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Stefano Stabellini

2012-Jul-26 15:33 UTC

[PATCH 00/24] Introduce Xen support on ARM

Hi all,
this patch series implements Xen support for ARMv7 with virtualization
extensions.  It allows a Linux guest to boot as dom0 and
as domU on Xen on ARM. PV console, disk and network frontends and
backends are all working correctly.

It has been tested on a Versatile Express Cortex A15 emulator, using the
latest Xen, and a simple ad-hoc tool to build guest domains
(marc.info/?l=xen-devel&m=134089788016546).

The patch marked with [HACK] shouldn''t be applied and is part of the
series only because it is needed to create domUs.

I am also attaching to this email the dts''es that I am currently using
for dom0 and domU: vexpress-v2p-ca15-tc1.dts is the dts used for dom0
and it is passed to Linux by Xen, while vexpress-virt.dts is the dts
used for other domUs and it is appended in binary form to the guest
kernel image. I am not sure where they are supposed to live yet, so I am
just attaching them here so that people can actually try out this series
if they want to.

Comments are very welcome!


Ian Campbell (2):
      ARM: enable earlyprintk=xen
      [HACK] xen/arm: implement xen_remap_domain_mfn_range

Stefano Stabellini (22):
      arm: initial Xen support
      xen/arm: hypercalls
      xen/arm: page.h definitions
      xen/arm: sync_bitops
      xen/arm: empty implementation of grant_table arch specific functions
      xen: missing includes
      xen/arm: Xen detection and shared_info page mapping
      xen/arm: Introduce xen_pfn_t for pfn and mfn types
      xen/arm: compile and run xenbus
      xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM
      xen/arm: introduce CONFIG_XEN on ARM
      xen/arm: Introduce xen_guest_init
      xen/arm: get privilege status
      xen/arm: initialize grant_table on ARM
      xen/arm: receive Xen events on ARM
      xen/arm: implement alloc/free_xenballooned_pages with alloc_pages/kfree
      xen: allow privcmd for HVM guests
      xen/arm: compile blkfront and blkback
      xen/arm: compile netback
      xen: update xen_add_to_physmap interface
      arm/v2m: initialize arch_timers even if v2m_timer is not present
      hvc_xen: allow dom0_write_console for HVM guests

 arch/arm/Kconfig                           |   10 ++
 arch/arm/Makefile                          |    1 +
 arch/arm/include/asm/hypervisor.h          |    6 +
 arch/arm/include/asm/sync_bitops.h         |   17 ++
 arch/arm/include/asm/xen/hypercall.h       |   69 ++++++++
 arch/arm/include/asm/xen/hypervisor.h      |   19 +++
 arch/arm/include/asm/xen/interface.h       |   66 ++++++++
 arch/arm/include/asm/xen/page.h            |   77 +++++++++
 arch/arm/kernel/early_printk.c             |   11 ++-
 arch/arm/mach-vexpress/v2m.c               |   11 +-
 arch/arm/xen/Makefile                      |    1 +
 arch/arm/xen/enlighten.c                   |  244 ++++++++++++++++++++++++++++
 arch/arm/xen/grant-table.c                 |   53 ++++++
 arch/arm/xen/hypercall.S                   |   65 ++++++++
 arch/ia64/include/asm/xen/interface.h      |    2 +-
 arch/x86/include/asm/xen/interface.h       |    2 +
 arch/x86/xen/enlighten.c                   |    9 +
 arch/x86/xen/irq.c                         |    1 +
 arch/x86/xen/xen-ops.h                     |    1 -
 drivers/block/xen-blkback/blkback.c        |    1 +
 drivers/net/xen-netback/netback.c          |    1 +
 drivers/net/xen-netfront.c                 |    1 +
 drivers/tty/hvc/hvc_xen.c                  |   14 +-
 drivers/xen/Makefile                       |    9 +-
 drivers/xen/events.c                       |   18 ++-
 drivers/xen/grant-table.c                  |    3 +-
 drivers/xen/privcmd.c                      |   20 +--
 drivers/xen/xenbus/xenbus_comms.c          |    2 +-
 drivers/xen/xenbus/xenbus_probe.c          |   27 ++--
 drivers/xen/xenbus/xenbus_probe_frontend.c |    1 +
 drivers/xen/xenbus/xenbus_xs.c             |    1 +
 drivers/xen/xenfs/super.c                  |    7 +
 include/xen/events.h                       |    2 +
 include/xen/interface/features.h           |    3 +
 include/xen/interface/grant_table.h        |    4 +-
 include/xen/interface/io/protocols.h       |    3 +
 include/xen/interface/memory.h             |   19 ++-
 include/xen/interface/platform.h           |    4 +-
 include/xen/interface/xen.h                |    9 +-
 include/xen/privcmd.h                      |    3 +-
 include/xen/xen.h                          |    4 +-
 41 files changed, 763 insertions(+), 58 deletions(-)


A branch based on 3.5-rc7 is available here:

git://xenbits.xen.org/people/sstabellini/linux-pvhvm.git 3.5-rc7-arm-1

Cheers,

Stefano

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 01/24] arm: initial Xen support

- Basic hypervisor.h and interface.h definitions.
- Skelethon enlighten.c, set xen_start_info to an empty struct.
- Do not limit xen_initial_domain to PV guests.

The new code only compiles when CONFIG_XEN is set, that is going to be
added to arch/arm/Kconfig in a later patch.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/Makefile                     |    1 +
 arch/arm/include/asm/hypervisor.h     |    6 +++
 arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
 arch/arm/include/asm/xen/interface.h  |   64 +++++++++++++++++++++++++++++++++
 arch/arm/xen/Makefile                 |    1 +
 arch/arm/xen/enlighten.c              |   35 ++++++++++++++++++
 include/xen/xen.h                     |    2 +-
 7 files changed, 127 insertions(+), 1 deletions(-)
 create mode 100644 arch/arm/include/asm/hypervisor.h
 create mode 100644 arch/arm/include/asm/xen/hypervisor.h
 create mode 100644 arch/arm/include/asm/xen/interface.h
 create mode 100644 arch/arm/xen/Makefile
 create mode 100644 arch/arm/xen/enlighten.c

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 0298b00..70aaa82 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -246,6 +246,7 @@ endif
 core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
 core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
 core-$(CONFIG_VFP)		+= arch/arm/vfp/
+core-$(CONFIG_XEN)		+= arch/arm/xen/
 
 # If we have a machine-specific directory, then include it in the build.
 core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
diff --git a/arch/arm/include/asm/hypervisor.h
b/arch/arm/include/asm/hypervisor.h
new file mode 100644
index 0000000..b90d9e5
--- /dev/null
+++ b/arch/arm/include/asm/hypervisor.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_ARM_HYPERVISOR_H
+#define _ASM_ARM_HYPERVISOR_H
+
+#include <asm/xen/hypervisor.h>
+
+#endif
diff --git a/arch/arm/include/asm/xen/hypervisor.h
b/arch/arm/include/asm/xen/hypervisor.h
new file mode 100644
index 0000000..d7ab99a
--- /dev/null
+++ b/arch/arm/include/asm/xen/hypervisor.h
@@ -0,0 +1,19 @@
+#ifndef _ASM_ARM_XEN_HYPERVISOR_H
+#define _ASM_ARM_XEN_HYPERVISOR_H
+
+extern struct shared_info *HYPERVISOR_shared_info;
+extern struct start_info *xen_start_info;
+
+/* Lazy mode for batching updates / context switch */
+enum paravirt_lazy_mode {
+	PARAVIRT_LAZY_NONE,
+	PARAVIRT_LAZY_MMU,
+	PARAVIRT_LAZY_CPU,
+};
+
+static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
+{
+	return PARAVIRT_LAZY_NONE;
+}
+
+#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
diff --git a/arch/arm/include/asm/xen/interface.h
b/arch/arm/include/asm/xen/interface.h
new file mode 100644
index 0000000..6c3ab59
--- /dev/null
+++ b/arch/arm/include/asm/xen/interface.h
@@ -0,0 +1,64 @@
+/******************************************************************************
+ * Guest OS interface to ARM Xen.
+ *
+ * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2011
+ */
+
+#ifndef _ASM_ARM_XEN_INTERFACE_H
+#define _ASM_ARM_XEN_INTERFACE_H
+
+#include <linux/types.h>
+
+#define __DEFINE_GUEST_HANDLE(name, type) \
+	typedef type * __guest_handle_ ## name
+
+#define DEFINE_GUEST_HANDLE_STRUCT(name) \
+	__DEFINE_GUEST_HANDLE(name, struct name)
+#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
+#define GUEST_HANDLE(name)        __guest_handle_ ## name
+
+#define set_xen_guest_handle(hnd, val)			\
+	do {						\
+		if (sizeof(hnd) == 8)			\
+			*(uint64_t *)&(hnd) = 0;	\
+		(hnd) = val;				\
+	} while (0)
+
+#ifndef __ASSEMBLY__
+/* Guest handles for primitive C types. */
+__DEFINE_GUEST_HANDLE(uchar, unsigned char);
+__DEFINE_GUEST_HANDLE(uint,  unsigned int);
+__DEFINE_GUEST_HANDLE(ulong, unsigned long);
+DEFINE_GUEST_HANDLE(char);
+DEFINE_GUEST_HANDLE(int);
+DEFINE_GUEST_HANDLE(long);
+DEFINE_GUEST_HANDLE(void);
+DEFINE_GUEST_HANDLE(uint64_t);
+DEFINE_GUEST_HANDLE(uint32_t);
+
+/* Maximum number of virtual CPUs in multi-processor guests. */
+#define MAX_VIRT_CPUS 1
+
+struct arch_vcpu_info { };
+struct arch_shared_info { };
+
+/* XXX: Move pvclock definitions some place arch independent */
+struct pvclock_vcpu_time_info {
+	u32   version;
+	u32   pad0;
+	u64   tsc_timestamp;
+	u64   system_time;
+	u32   tsc_to_system_mul;
+	s8    tsc_shift;
+	u8    flags;
+	u8    pad[2];
+} __attribute__((__packed__)); /* 32 bytes */
+
+struct pvclock_wall_clock {
+	u32   version;
+	u32   sec;
+	u32   nsec;
+} __attribute__((__packed__));
+#endif
+
+#endif /* _ASM_ARM_XEN_INTERFACE_H */
diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
new file mode 100644
index 0000000..0bad594
--- /dev/null
+++ b/arch/arm/xen/Makefile
@@ -0,0 +1 @@
+obj-y		:= enlighten.o
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
new file mode 100644
index 0000000..d27c2a6
--- /dev/null
+++ b/arch/arm/xen/enlighten.c
@@ -0,0 +1,35 @@
+#include <xen/xen.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/memory.h>
+#include <xen/platform_pci.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+#include <linux/module.h>
+
+struct start_info _xen_start_info;
+struct start_info *xen_start_info = &_xen_start_info;
+EXPORT_SYMBOL_GPL(xen_start_info);
+
+enum xen_domain_type xen_domain_type = XEN_NATIVE;
+EXPORT_SYMBOL_GPL(xen_domain_type);
+
+struct shared_info xen_dummy_shared_info;
+struct shared_info *HYPERVISOR_shared_info = (void
*)&xen_dummy_shared_info;
+
+DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
+
+/* XXX: to be removed */
+__read_mostly int xen_have_vector_callback;
+EXPORT_SYMBOL_GPL(xen_have_vector_callback);
+
+int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
+EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
+
+int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
+			       unsigned long addr,
+			       unsigned long mfn, int nr,
+			       pgprot_t prot, unsigned domid)
+{
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
diff --git a/include/xen/xen.h b/include/xen/xen.h
index a164024..2c0d3a5 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -23,7 +23,7 @@ extern enum xen_domain_type xen_domain_type;
 #include <xen/interface/xen.h>
 #include <asm/xen/hypervisor.h>
 
-#define xen_initial_domain()	(xen_pv_domain() && \
+#define xen_initial_domain()	(xen_domain() && \
 				 xen_start_info->flags & SIF_INITDOMAIN)
 #else  /* !CONFIG_XEN_DOM0 */
 #define xen_initial_domain()	(0)
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 02/24] xen/arm: hypercalls

Use r12 to pass the hypercall number to the hypervisor.

We need a register to pass the hypercall number because we might not
know it at compile time and HVC only takes an immediate argument.

Among the available registers r12 seems to be the best choice because it
is defined as "intra-procedure call scratch register".

Use the ISS to pass an hypervisor specific tag.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/include/asm/xen/hypercall.h |   50 ++++++++++++++++++++++++++
 arch/arm/xen/Makefile                |    2 +-
 arch/arm/xen/hypercall.S             |   65 ++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+), 1 deletions(-)
 create mode 100644 arch/arm/include/asm/xen/hypercall.h
 create mode 100644 arch/arm/xen/hypercall.S

diff --git a/arch/arm/include/asm/xen/hypercall.h
b/arch/arm/include/asm/xen/hypercall.h
new file mode 100644
index 0000000..4ac0624
--- /dev/null
+++ b/arch/arm/include/asm/xen/hypercall.h
@@ -0,0 +1,50 @@
+/******************************************************************************
+ * hypercall.h
+ *
+ * Linux-specific hypervisor handling.
+ *
+ * Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>, Citrix, 2012
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software
without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef _ASM_ARM_XEN_HYPERCALL_H
+#define _ASM_ARM_XEN_HYPERCALL_H
+
+#include <xen/interface/xen.h>
+
+long privcmd_call(unsigned call, unsigned long a1,
+		unsigned long a2, unsigned long a3,
+		unsigned long a4, unsigned long a5);
+int HYPERVISOR_xen_version(int cmd, void *arg);
+int HYPERVISOR_console_io(int cmd, int count, char *str);
+int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
+int HYPERVISOR_sched_op(int cmd, void *arg);
+int HYPERVISOR_event_channel_op(int cmd, void *arg);
+unsigned long HYPERVISOR_hvm_op(int op, void *arg);
+int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
+int HYPERVISOR_physdev_op(int cmd, void *arg);
+
+#endif /* _ASM_ARM_XEN_HYPERCALL_H */
diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
index 0bad594..b9d6acc 100644
--- a/arch/arm/xen/Makefile
+++ b/arch/arm/xen/Makefile
@@ -1 +1 @@
-obj-y		:= enlighten.o
+obj-y		:= enlighten.o hypercall.o
diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
new file mode 100644
index 0000000..038cc5b
--- /dev/null
+++ b/arch/arm/xen/hypercall.S
@@ -0,0 +1,65 @@
+/******************************************************************************
+ * hypercall.S
+ *
+ * Xen hypercall wrappers
+ *
+ * The Xen hypercall calling convention is very similar to the ARM
+ * procedure calling convention: the first paramter is passed in r0, the
+ * second in r1, the third in r2 and the third in r3. Considering that
+ * Xen hypercalls have 5 arguments at most, the fifth paramter is passed
+ * in r4, differently from the procedure calling convention of using the
+ * stack for that case.
+ *
+ * The hypercall number is passed in r12.
+ *
+ * The return value is in r0.
+ *
+ * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
+ * hypercall tag.
+ *
+ * Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>, Citrix, 2012
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <xen/interface/xen.h>
+
+
+/* HVC 0xEA1 */
+#ifdef CONFIG_THUMB2_KERNEL
+#define xen_hvc .word 0xf7e08ea1
+#else
+#define xen_hvc .word 0xe140ea71
+#endif
+
+/* We need to save and restore r4, because Xen clobbers it. */
+#define HYPERCALL(hypercall)			\
+ENTRY(HYPERVISOR_##hypercall)			\
+	mov r12, #__HYPERVISOR_##hypercall;	\
+	xen_hvc;							\
+	mov pc, lr;							\
+ENDPROC(HYPERVISOR_##hypercall)
+
+                .text
+
+HYPERCALL(xen_version);
+HYPERCALL(console_io);
+HYPERCALL(grant_table_op);
+HYPERCALL(sched_op);
+HYPERCALL(event_channel_op);
+HYPERCALL(hvm_op);
+HYPERCALL(memory_op);
+HYPERCALL(physdev_op);
+
+ENTRY(privcmd_call)
+	stmdb	sp!, {r4}
+	mov r12, r0
+	mov r0, r1
+	mov r1, r2
+	mov r2, r3
+	ldr r3, [sp, #8]
+	ldr r4, [sp, #4]
+	xen_hvc
+	pop {r4}
+	mov pc, lr
+ENDPROC(privcmd_call);
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 03/24] xen/arm: page.h definitions

ARM Xen guests always use paging in hardware, like PV on HVM guests in
the X86 world.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/include/asm/xen/page.h |   77 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 77 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/include/asm/xen/page.h

diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
new file mode 100644
index 0000000..6cfe9a1
--- /dev/null
+++ b/arch/arm/include/asm/xen/page.h
@@ -0,0 +1,77 @@
+#ifndef _ASM_ARM_XEN_PAGE_H
+#define _ASM_ARM_XEN_PAGE_H
+
+#include <asm/page.h>
+#include <linux/pfn.h>
+#include <linux/types.h>
+#include <asm/pgtable.h>
+#include <xen/interface/grant_table.h>
+
+#define pfn_to_mfn(pfn)			(pfn)
+#define phys_to_machine_mapping_valid	(1)
+#define mfn_to_pfn(mfn)			(mfn)
+#define mfn_to_virt(m)			(__va(mfn_to_pfn(m) << PAGE_SHIFT))
+
+#define pte_mfn	    pte_pfn
+#define mfn_pte	    pfn_pte
+
+/* Xen machine address */
+typedef struct xmaddr {
+	phys_addr_t maddr;
+} xmaddr_t;
+
+/* Xen pseudo-physical address */
+typedef struct xpaddr {
+	phys_addr_t paddr;
+} xpaddr_t;
+
+#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
+#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })
+
+static inline xmaddr_t phys_to_machine(xpaddr_t phys)
+{
+	unsigned offset = phys.paddr & ~PAGE_MASK;
+	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
+}
+
+static inline xpaddr_t machine_to_phys(xmaddr_t machine)
+{
+	unsigned offset = machine.maddr & ~PAGE_MASK;
+	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
+}
+/* VIRT <-> MACHINE conversion */
+#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
+#define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
+#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
+#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))
+
+static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
+{
+	/* XXX: assuming it is mapped in the kernel 1:1 */
+	return virt_to_machine(vaddr);
+}
+
+/* XXX: this shouldn''t be here */
+static inline pte_t *lookup_address(unsigned long address, unsigned int *level)
+{
+	BUG();
+	return NULL;
+}
+
+static inline int m2p_add_override(unsigned long mfn, struct page *page,
+		struct gnttab_map_grant_ref *kmap_op)
+{
+	return 0;
+}
+
+static inline int m2p_remove_override(struct page *page, bool clear_pte)
+{
+	return 0;
+}
+
+static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+	BUG();
+	return false;
+}
+#endif /* _ASM_ARM_XEN_PAGE_H */
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 04/24] xen/arm: sync_bitops

sync_bitops functions are equivalent to the SMP implementation of the
original functions, independently from CONFIG_SMP being defined.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/include/asm/sync_bitops.h |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/include/asm/sync_bitops.h

diff --git a/arch/arm/include/asm/sync_bitops.h
b/arch/arm/include/asm/sync_bitops.h
new file mode 100644
index 0000000..d975092903
--- /dev/null
+++ b/arch/arm/include/asm/sync_bitops.h
@@ -0,0 +1,17 @@
+#ifndef __ASM_SYNC_BITOPS_H__
+#define __ASM_SYNC_BITOPS_H__
+
+#include <asm/bitops.h>
+#include <asm/system.h>
+
+#define sync_set_bit(nr, p)		_set_bit(nr, p)
+#define sync_clear_bit(nr, p)		_clear_bit(nr, p)
+#define sync_change_bit(nr, p)		_change_bit(nr, p)
+#define sync_test_and_set_bit(nr, p)	_test_and_set_bit(nr, p)
+#define sync_test_and_clear_bit(nr, p)	_test_and_clear_bit(nr, p)
+#define sync_test_and_change_bit(nr, p)	_test_and_change_bit(nr, p)
+#define sync_test_bit(nr, addr)		test_bit(nr, addr)
+#define sync_cmpxchg			cmpxchg
+
+
+#endif
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/xen/Makefile      |    2 +-
 arch/arm/xen/grant-table.c |   53 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletions(-)
 create mode 100644 arch/arm/xen/grant-table.c

diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
index b9d6acc..4384103 100644
--- a/arch/arm/xen/Makefile
+++ b/arch/arm/xen/Makefile
@@ -1 +1 @@
-obj-y		:= enlighten.o hypercall.o
+obj-y		:= enlighten.o hypercall.o grant-table.o
diff --git a/arch/arm/xen/grant-table.c b/arch/arm/xen/grant-table.c
new file mode 100644
index 0000000..0a4ee80
--- /dev/null
+++ b/arch/arm/xen/grant-table.c
@@ -0,0 +1,53 @@
+/******************************************************************************
+ * grant_table.c
+ * ARM specific part
+ *
+ * Granting foreign access to our memory reservation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software
without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <xen/interface/xen.h>
+#include <xen/page.h>
+#include <xen/grant_table.h>
+
+int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
+			   unsigned long max_nr_gframes,
+			   void **__shared)
+{
+	return -1;
+}
+
+void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
+{
+	return;
+}
+
+int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
+			   unsigned long max_nr_gframes,
+			   grant_status_t **__shared)
+{
+	return -1;
+}
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 06/24] xen: missing includes

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 drivers/tty/hvc/hvc_xen.c                  |    2 ++
 drivers/xen/grant-table.c                  |    1 +
 drivers/xen/xenbus/xenbus_probe_frontend.c |    1 +
 include/xen/interface/xen.h                |    3 +++
 include/xen/privcmd.h                      |    1 +
 5 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 944eaeb..dc07f56 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -21,6 +21,7 @@
 #include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/irq.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/list.h>
@@ -35,6 +36,7 @@
 #include <xen/page.h>
 #include <xen/events.h>
 #include <xen/interface/io/console.h>
+#include <xen/interface/sched.h>
 #include <xen/hvc-console.h>
 #include <xen/xenbus.h>
 
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 0bfc1ef..1d0d95e 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -47,6 +47,7 @@
 #include <xen/interface/memory.h>
 #include <xen/hvc-console.h>
 #include <asm/xen/hypercall.h>
+#include <asm/xen/interface.h>
 
 #include <asm/pgtable.h>
 #include <asm/sync_bitops.h>
diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c
b/drivers/xen/xenbus/xenbus_probe_frontend.c
index a31b54d..3159a37 100644
--- a/drivers/xen/xenbus/xenbus_probe_frontend.c
+++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
@@ -21,6 +21,7 @@
 #include <xen/xenbus.h>
 #include <xen/events.h>
 #include <xen/page.h>
+#include <xen/xen.h>
 
 #include <xen/platform_pci.h>
 
diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
index a890804..4f29f33 100644
--- a/include/xen/interface/xen.h
+++ b/include/xen/interface/xen.h
@@ -10,7 +10,10 @@
 #define __XEN_PUBLIC_XEN_H__
 
 #include <asm/xen/interface.h>
+#include <linux/types.h>
+#ifdef CONFIG_X86
 #include <asm/pvclock-abi.h>
+#endif
 
 /*
  * XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS).
diff --git a/include/xen/privcmd.h b/include/xen/privcmd.h
index 17857fb..4d58881 100644
--- a/include/xen/privcmd.h
+++ b/include/xen/privcmd.h
@@ -35,6 +35,7 @@
 
 #include <linux/types.h>
 #include <linux/compiler.h>
+#include <xen/interface/xen.h>
 
 typedef unsigned long xen_pfn_t;
 
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

Check for a "/xen" node in the device tree, if it is present set
xen_domain_type to XEN_HVM_DOMAIN and continue initialization.

Map the real shared info page using XENMEM_add_to_physmap with
XENMAPSPACE_shared_info.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/xen/enlighten.c |   56 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 56 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index d27c2a6..8c923af 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -5,6 +5,9 @@
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
 
 struct start_info _xen_start_info;
 struct start_info *xen_start_info = &_xen_start_info;
@@ -33,3 +36,56 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 	return -ENOSYS;
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
+
+/*
+ * == Xen Device Tree format =+ * - /xen node;
+ * - compatible "arm,xen";
+ * - one interrupt for Xen event notifications;
+ * - one memory region to map the grant_table.
+ */
+static int __init xen_guest_init(void)
+{
+	int cpu;
+	struct xen_add_to_physmap xatp;
+	static struct shared_info *shared_info_page = 0;
+	struct device_node *node;
+
+	node = of_find_compatible_node(NULL, NULL, "arm,xen");
+	if (!node) {
+		pr_info("No Xen support\n");
+		return 0;
+	}
+	xen_domain_type = XEN_HVM_DOMAIN;
+
+	if (!shared_info_page)
+		shared_info_page = (struct shared_info *)
+			get_zeroed_page(GFP_KERNEL);
+	if (!shared_info_page) {
+		pr_err("not enough memory");
+		return -ENOMEM;
+	}
+	xatp.domid = DOMID_SELF;
+	xatp.idx = 0;
+	xatp.space = XENMAPSPACE_shared_info;
+	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
+	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
+		BUG();
+
+	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
+
+	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+	 * page, we use it in the event channel upcall and in some pvclock
+	 * related functions. We don''t need the vcpu_info placement
+	 * optimizations because we don''t use any pv_mmu or pv_irq op on
+	 * HVM.
+	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
+	 * online but xen_hvm_init_shared_info is run at resume time too and
+	 * in that case multiple vcpus might be online. */
+	for_each_online_cpu(cpu) {
+		per_cpu(xen_vcpu, cpu) +			&HYPERVISOR_shared_info->vcpu_info[cpu];
+	}
+	return 0;
+}
+core_initcall(xen_guest_init);
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types

All the original Xen headers have xen_pfn_t as mfn and pfn type, however
when they have been imported in Linux, xen_pfn_t has been replaced with
unsigned long. That might work for x86 and ia64 but it does not for arm.
Bring back xen_pfn_t and let each architecture define xen_pfn_t as they
see fit.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/include/asm/xen/interface.h  |    2 ++
 arch/ia64/include/asm/xen/interface.h |    2 +-
 arch/x86/include/asm/xen/interface.h  |    2 ++
 include/xen/interface/grant_table.h   |    4 ++--
 include/xen/interface/memory.h        |    6 +++---
 include/xen/interface/platform.h      |    4 ++--
 include/xen/interface/xen.h           |    6 +++---
 include/xen/privcmd.h                 |    2 --
 8 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/arch/arm/include/asm/xen/interface.h
b/arch/arm/include/asm/xen/interface.h
index 6c3ab59..76b1ebe 100644
--- a/arch/arm/include/asm/xen/interface.h
+++ b/arch/arm/include/asm/xen/interface.h
@@ -25,6 +25,7 @@
 	} while (0)
 
 #ifndef __ASSEMBLY__
+typedef uint64_t xen_pfn_t;
 /* Guest handles for primitive C types. */
 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
 __DEFINE_GUEST_HANDLE(uint,  unsigned int);
@@ -35,6 +36,7 @@ DEFINE_GUEST_HANDLE(long);
 DEFINE_GUEST_HANDLE(void);
 DEFINE_GUEST_HANDLE(uint64_t);
 DEFINE_GUEST_HANDLE(uint32_t);
+DEFINE_GUEST_HANDLE(xen_pfn_t);
 
 /* Maximum number of virtual CPUs in multi-processor guests. */
 #define MAX_VIRT_CPUS 1
diff --git a/arch/ia64/include/asm/xen/interface.h
b/arch/ia64/include/asm/xen/interface.h
index 09d5f7f..9efa068 100644
--- a/arch/ia64/include/asm/xen/interface.h
+++ b/arch/ia64/include/asm/xen/interface.h
@@ -67,6 +67,7 @@
 #define set_xen_guest_handle(hnd, val)	do { (hnd).p = val; } while (0)
 
 #ifndef __ASSEMBLY__
+typedef unsigned long xen_pfn_t;
 /* Guest handles for primitive C types. */
 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
 __DEFINE_GUEST_HANDLE(uint, unsigned int);
@@ -79,7 +80,6 @@ DEFINE_GUEST_HANDLE(void);
 DEFINE_GUEST_HANDLE(uint64_t);
 DEFINE_GUEST_HANDLE(uint32_t);
 
-typedef unsigned long xen_pfn_t;
 DEFINE_GUEST_HANDLE(xen_pfn_t);
 #define PRI_xen_pfn	"lx"
 #endif
diff --git a/arch/x86/include/asm/xen/interface.h
b/arch/x86/include/asm/xen/interface.h
index cbf0c9d..24c1b07 100644
--- a/arch/x86/include/asm/xen/interface.h
+++ b/arch/x86/include/asm/xen/interface.h
@@ -47,6 +47,7 @@
 #endif
 
 #ifndef __ASSEMBLY__
+typedef unsigned long xen_pfn_t;
 /* Guest handles for primitive C types. */
 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
 __DEFINE_GUEST_HANDLE(uint,  unsigned int);
@@ -57,6 +58,7 @@ DEFINE_GUEST_HANDLE(long);
 DEFINE_GUEST_HANDLE(void);
 DEFINE_GUEST_HANDLE(uint64_t);
 DEFINE_GUEST_HANDLE(uint32_t);
+DEFINE_GUEST_HANDLE(xen_pfn_t);
 #endif
 
 #ifndef HYPERVISOR_VIRT_START
diff --git a/include/xen/interface/grant_table.h
b/include/xen/interface/grant_table.h
index a17d844..7da811b 100644
--- a/include/xen/interface/grant_table.h
+++ b/include/xen/interface/grant_table.h
@@ -338,7 +338,7 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_dump_table);
 #define GNTTABOP_transfer                4
 struct gnttab_transfer {
     /* IN parameters. */
-    unsigned long mfn;
+    xen_pfn_t mfn;
     domid_t       domid;
     grant_ref_t   ref;
     /* OUT parameters. */
@@ -375,7 +375,7 @@ struct gnttab_copy {
 	struct {
 		union {
 			grant_ref_t ref;
-			unsigned long   gmfn;
+			xen_pfn_t   gmfn;
 		} u;
 		domid_t  domid;
 		uint16_t offset;
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index eac3ce1..abbbff0 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -31,7 +31,7 @@ struct xen_memory_reservation {
      *   OUT: GMFN bases of extents that were allocated
      *   (NB. This command also updates the mach_to_phys translation table)
      */
-    GUEST_HANDLE(ulong) extent_start;
+    GUEST_HANDLE(xen_pfn_t) extent_start;
 
     /* Number of extents, and size/alignment of each (2^extent_order pages). */
     unsigned long  nr_extents;
@@ -130,7 +130,7 @@ struct xen_machphys_mfn_list {
      * any large discontiguities in the machine address space, 2MB gaps in
      * the machphys table will be represented by an MFN base of zero.
      */
-    GUEST_HANDLE(ulong) extent_start;
+    GUEST_HANDLE(xen_pfn_t) extent_start;
 
     /*
      * Number of extents written to the above array. This will be smaller
@@ -172,7 +172,7 @@ struct xen_add_to_physmap {
     unsigned long idx;
 
     /* GPFN where the source mapping page should appear. */
-    unsigned long gpfn;
+    xen_pfn_t gpfn;
 };
 DEFINE_GUEST_HANDLE_STRUCT(xen_add_to_physmap);
 
diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h
index 486653f..0bea470 100644
--- a/include/xen/interface/platform.h
+++ b/include/xen/interface/platform.h
@@ -54,7 +54,7 @@ DEFINE_GUEST_HANDLE_STRUCT(xenpf_settime_t);
 #define XENPF_add_memtype         31
 struct xenpf_add_memtype {
 	/* IN variables. */
-	unsigned long mfn;
+	xen_pfn_t mfn;
 	uint64_t nr_mfns;
 	uint32_t type;
 	/* OUT variables. */
@@ -84,7 +84,7 @@ struct xenpf_read_memtype {
 	/* IN variables. */
 	uint32_t reg;
 	/* OUT variables. */
-	unsigned long mfn;
+	xen_pfn_t mfn;
 	uint64_t nr_mfns;
 	uint32_t type;
 };
diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
index 4f29f33..d59a991 100644
--- a/include/xen/interface/xen.h
+++ b/include/xen/interface/xen.h
@@ -192,7 +192,7 @@ struct mmuext_op {
 	unsigned int cmd;
 	union {
 		/* [UN]PIN_TABLE, NEW_BASEPTR, NEW_USER_BASEPTR */
-		unsigned long mfn;
+		xen_pfn_t mfn;
 		/* INVLPG_LOCAL, INVLPG_ALL, SET_LDT */
 		unsigned long linear_addr;
 	} arg1;
@@ -432,11 +432,11 @@ struct start_info {
 	unsigned long nr_pages;     /* Total pages allocated to this domain.  */
 	unsigned long shared_info;  /* MACHINE address of shared info struct. */
 	uint32_t flags;             /* SIF_xxx flags.                         */
-	unsigned long store_mfn;    /* MACHINE page number of shared page.    */
+	xen_pfn_t store_mfn;        /* MACHINE page number of shared page.    */
 	uint32_t store_evtchn;      /* Event channel for store communication. */
 	union {
 		struct {
-			unsigned long mfn;  /* MACHINE page number of console page.   */
+			xen_pfn_t mfn;      /* MACHINE page number of console page.   */
 			uint32_t  evtchn;   /* Event channel for console page.        */
 		} domU;
 		struct {
diff --git a/include/xen/privcmd.h b/include/xen/privcmd.h
index 4d58881..45c1aa1 100644
--- a/include/xen/privcmd.h
+++ b/include/xen/privcmd.h
@@ -37,8 +37,6 @@
 #include <linux/compiler.h>
 #include <xen/interface/xen.h>
 
-typedef unsigned long xen_pfn_t;
-
 struct privcmd_hypercall {
 	__u64 op;
 	__u64 arg[5];
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 09/24] xen/arm: compile and run xenbus

bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not
an error.

If Linux is running as an HVM domain and is running as Dom0, use
xenstored_local_init to initialize the xenstore page and event channel.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 drivers/xen/xenbus/xenbus_comms.c |    2 +-
 drivers/xen/xenbus/xenbus_probe.c |   27 +++++++++++++++++----------
 drivers/xen/xenbus/xenbus_xs.c    |    1 +
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_comms.c
b/drivers/xen/xenbus/xenbus_comms.c
index 52fe7ad..c5aa55c 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -224,7 +224,7 @@ int xb_init_comms(void)
 		int err;
 		err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
 						0, "xenbus", &xb_waitq);
-		if (err <= 0) {
+		if (err < 0) {
 			printk(KERN_ERR "XENBUS request irq failed %i\n", err);
 			return err;
 		}
diff --git a/drivers/xen/xenbus/xenbus_probe.c
b/drivers/xen/xenbus/xenbus_probe.c
index b793723..3ae47c2 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -729,16 +729,23 @@ static int __init xenbus_init(void)
 	xenbus_ring_ops_init();
 
 	if (xen_hvm_domain()) {
-		uint64_t v = 0;
-		err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
-		if (err)
-			goto out_error;
-		xen_store_evtchn = (int)v;
-		err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
-		if (err)
-			goto out_error;
-		xen_store_mfn = (unsigned long)v;
-		xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
+		if (xen_initial_domain()) {
+			err = xenstored_local_init();
+			xen_store_interface +				phys_to_virt(xen_store_mfn << PAGE_SHIFT);
+		} else {
+			uint64_t v = 0;
+			err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
+			if (err)
+				goto out_error;
+			xen_store_evtchn = (int)v;
+			err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
+			if (err)
+				goto out_error;
+			xen_store_mfn = (unsigned long)v;
+			xen_store_interface +				ioremap(xen_store_mfn << PAGE_SHIFT,
PAGE_SIZE);
+		}
 	} else {
 		xen_store_evtchn = xen_start_info->store_evtchn;
 		xen_store_mfn = xen_start_info->store_mfn;
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index d1c217b..f7feb3d 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -44,6 +44,7 @@
 #include <linux/rwsem.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <asm/xen/hypervisor.h>
 #include <xen/xenbus.h>
 #include <xen/xen.h>
 #include "xenbus_comms.h"
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 drivers/xen/Makefile |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index fc34886..0cfa6c47 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -1,11 +1,15 @@
-obj-y	+= grant-table.o features.o events.o manage.o balloon.o
+ifneq ($(CONFIG_ARM),y)
+obj-y	+= manage.o balloon.o
+obj-$(CONFIG_XEN_DOM0)			+= pci.o acpi.o
+obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
+endif
+obj-y	+= grant-table.o features.o events.o
 obj-y	+= xenbus/
 
 nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_features.o			:= $(nostackp)
 
 obj-$(CONFIG_BLOCK)			+= biomerge.o
-obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
 obj-$(CONFIG_XEN_XENCOMM)		+= xencomm.o
 obj-$(CONFIG_XEN_BALLOON)		+= xen-balloon.o
 obj-$(CONFIG_XEN_SELFBALLOONING)	+= xen-selfballoon.o
@@ -17,7 +21,6 @@ obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
 obj-$(CONFIG_XEN_PVHVM)			+= platform-pci.o
 obj-$(CONFIG_XEN_TMEM)			+= tmem.o
 obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o
-obj-$(CONFIG_XEN_DOM0)			+= pci.o acpi.o
 obj-$(CONFIG_XEN_PCIDEV_BACKEND)	+= xen-pciback/
 obj-$(CONFIG_XEN_PRIVCMD)		+= xen-privcmd.o
 obj-$(CONFIG_XEN_ACPI_PROCESSOR)	+= xen-acpi-processor.o
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 11/24] xen/arm: introduce CONFIG_XEN on ARM

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/Kconfig |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a91009c..9c54cb4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2228,6 +2228,16 @@ config NEON
 	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
 	  Extension.
 
+config XEN_DOM0
+	def_bool y
+
+config XEN
+	bool "Xen guest support on ARM"
+	depends on ARM && OF
+	select XEN_DOM0
+	help
+	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
+
 endmenu
 
 menu "Userspace binary formats"
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 12/24] xen/arm: Introduce xen_guest_init

We used to rely on a core_initcall to initialize Xen on ARM, however
core_initcalls are actually called after early consoles are initialized.
That means that hvc_xen.c is going to be initialized before Xen.

Given the lack of a better alternative, just call a new Xen
initialization function (xen_guest_init) from xen_cons_init.

xen_guest_init has to be arch independent, so write both an ARM and an
x86 implementation. The x86 implementation is currently empty because we
can be sure that xen_hvm_guest_init is called early enough.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/xen/enlighten.c  |    7 ++++++-
 arch/x86/xen/enlighten.c  |    8 ++++++++
 drivers/tty/hvc/hvc_xen.c |    7 ++++++-
 include/xen/xen.h         |    2 ++
 4 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 8c923af..dc68074 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -44,7 +44,7 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
  * - one interrupt for Xen event notifications;
  * - one memory region to map the grant_table.
  */
-static int __init xen_guest_init(void)
+int __init xen_guest_init(void)
 {
 	int cpu;
 	struct xen_add_to_physmap xatp;
@@ -58,6 +58,10 @@ static int __init xen_guest_init(void)
 	}
 	xen_domain_type = XEN_HVM_DOMAIN;
 
+	/* already setup */
+	if (shared_info_page != 0 && HYPERVISOR_shared_info ==
shared_info_page)
+		return 0;
+
 	if (!shared_info_page)
 		shared_info_page = (struct shared_info *)
 			get_zeroed_page(GFP_KERNEL);
@@ -88,4 +92,5 @@ static int __init xen_guest_init(void)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(xen_guest_init);
 core_initcall(xen_guest_init);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index ff962d4..6131d43 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1567,4 +1567,12 @@ const struct hypervisor_x86 x86_hyper_xen_hvm __refconst
= {
 	.init_platform		= xen_hvm_guest_init,
 };
 EXPORT_SYMBOL(x86_hyper_xen_hvm);
+
+int __init xen_guest_init(void)
+{
+	/* do nothing: rely on x86_hyper_xen_hvm for the initialization */
+	return 0;
+	
+}
+EXPORT_SYMBOL_GPL(xen_guest_init);
 #endif
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index dc07f56..3c04fb8 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -577,6 +577,12 @@ static void __exit xen_hvc_fini(void)
 static int xen_cons_init(void)
 {
 	const struct hv_ops *ops;
+	int r;
+
+	/* retrieve xen infos  */
+	r = xen_guest_init();
+	if (r < 0)
+		return r;
 
 	if (!xen_domain())
 		return 0;
@@ -584,7 +590,6 @@ static int xen_cons_init(void)
 	if (xen_initial_domain())
 		ops = &dom0_hvc_ops;
 	else {
-		int r;
 		ops = &domU_hvc_ops;
 
 		if (xen_hvm_domain())
diff --git a/include/xen/xen.h b/include/xen/xen.h
index 2c0d3a5..792a4d2 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -9,8 +9,10 @@ enum xen_domain_type {
 
 #ifdef CONFIG_XEN
 extern enum xen_domain_type xen_domain_type;
+int xen_guest_init(void);
 #else
 #define xen_domain_type		XEN_NATIVE
+static inline int xen_guest_init(void) { return 0; }
 #endif
 
 #define xen_domain()		(xen_domain_type != XEN_NATIVE)
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 13/24] xen/arm: get privilege status

Use Xen features to figure out if we are privileged.

XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/xen/enlighten.c         |    7 +++++++
 include/xen/interface/features.h |    3 +++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index dc68074..2e013cf 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -2,6 +2,7 @@
 #include <xen/interface/xen.h>
 #include <xen/interface/memory.h>
 #include <xen/platform_pci.h>
+#include <xen/features.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <linux/module.h>
@@ -58,6 +59,12 @@ int __init xen_guest_init(void)
 	}
 	xen_domain_type = XEN_HVM_DOMAIN;
 
+	xen_setup_features();
+	if (xen_feature(XENFEAT_dom0))
+		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
+	else
+		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
+
 	/* already setup */
 	if (shared_info_page != 0 && HYPERVISOR_shared_info ==
shared_info_page)
 		return 0;
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index b6ca39a..131a6cc 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -50,6 +50,9 @@
 /* x86: pirq can be used by HVM guests */
 #define XENFEAT_hvm_pirqs           10
 
+/* operation as Dom0 is supported */
+#define XENFEAT_dom0                      11
+
 #define XENFEAT_NR_SUBMAPS 1
 
 #endif /* __XEN_PUBLIC_FEATURES_H__ */
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 14/24] xen/arm: initialize grant_table on ARM

Initialize the grant table mapping at the address specified at index 0
in the DT under the /xen node.
After the grant table is initialized, call xenbus_probe (if not dom0).

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/xen/enlighten.c  |   13 +++++++++++++
 drivers/xen/grant-table.c |    2 +-
 2 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 2e013cf..854af1e 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -1,8 +1,12 @@
 #include <xen/xen.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/memory.h>
+#include <xen/interface/hvm/params.h>
 #include <xen/platform_pci.h>
 #include <xen/features.h>
+#include <xen/grant_table.h>
+#include <xen/hvm.h>
+#include <xen/xenbus.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <linux/module.h>
@@ -51,12 +55,16 @@ int __init xen_guest_init(void)
 	struct xen_add_to_physmap xatp;
 	static struct shared_info *shared_info_page = 0;
 	struct device_node *node;
+	struct resource res;
 
 	node = of_find_compatible_node(NULL, NULL, "arm,xen");
 	if (!node) {
 		pr_info("No Xen support\n");
 		return 0;
 	}
+	if (of_address_to_resource(node, 0, &res))
+		return -EINVAL;
+	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
 	xen_domain_type = XEN_HVM_DOMAIN;
 
 	xen_setup_features();
@@ -97,6 +105,11 @@ int __init xen_guest_init(void)
 		per_cpu(xen_vcpu, cpu)  			&HYPERVISOR_shared_info->vcpu_info[cpu];
 	}
+
+	gnttab_init();
+	if (!xen_initial_domain())
+		xenbus_probe(NULL);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xen_guest_init);
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 1d0d95e..fd2137a 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -62,7 +62,7 @@
 
 static grant_ref_t **gnttab_list;
 static unsigned int nr_grant_frames;
-static unsigned int boot_max_nr_grant_frames;
+static unsigned int boot_max_nr_grant_frames = 1;
 static int gnttab_free_count;
 static grant_ref_t gnttab_free_head;
 static DEFINE_SPINLOCK(gnttab_list_lock);
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 15/24] xen/arm: receive Xen events on ARM

Compile events.c on ARM.
Parse, map and enable the IRQ to get event notifications from the device
tree (node "/xen").

On ARM Linux irqs are not enabled by default:

- call enable_percpu_irq for xen_events_irq (drivers are supposed
to call enable_irq after request_irq);

- reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by
default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn''t call
irq_startup, that is responsible for calling irq_unmask at startup time.
As a result event channels remain masked.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/xen/enlighten.c |   33 +++++++++++++++++++++++++++++++++
 arch/x86/xen/enlighten.c |    1 +
 arch/x86/xen/irq.c       |    1 +
 arch/x86/xen/xen-ops.h   |    1 -
 drivers/xen/events.c     |   18 +++++++++++++++---
 include/xen/events.h     |    2 ++
 6 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 854af1e..60d6d36 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -7,8 +7,11 @@
 #include <xen/grant_table.h>
 #include <xen/hvm.h>
 #include <xen/xenbus.h>
+#include <xen/events.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -33,6 +36,8 @@ EXPORT_SYMBOL_GPL(xen_have_vector_callback);
 int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
 EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
 
+static __read_mostly int xen_events_irq = -1;
+
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
 			       unsigned long mfn, int nr,
@@ -65,6 +70,9 @@ int __init xen_guest_init(void)
 	if (of_address_to_resource(node, 0, &res))
 		return -EINVAL;
 	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
+	xen_events_irq = irq_of_parse_and_map(node, 0);
+	pr_info("Xen support found, events_irq=%d gnttab_frame_pfn=%lx\n",
+			xen_events_irq, xen_hvm_resume_frames);
 	xen_domain_type = XEN_HVM_DOMAIN;
 
 	xen_setup_features();
@@ -114,3 +122,28 @@ int __init xen_guest_init(void)
 }
 EXPORT_SYMBOL_GPL(xen_guest_init);
 core_initcall(xen_guest_init);
+
+static irqreturn_t xen_arm_callback(int irq, void *arg)
+{
+	xen_hvm_evtchn_do_upcall();
+	return 0;
+}
+
+static int __init xen_init_events(void)
+{
+	if (!xen_domain() || xen_events_irq < 0)
+		return -ENODEV;
+
+	xen_init_IRQ();
+
+	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
+			"events", xen_vcpu)) {
+		pr_err("Error requesting IRQ %d\n", xen_events_irq);
+		return -EINVAL;
+	}
+
+	enable_percpu_irq(xen_events_irq, 0);
+
+	return 0;
+}
+postcore_initcall(xen_init_events);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 6131d43..5a30502 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -33,6 +33,7 @@
 #include <linux/memblock.h>
 
 #include <xen/xen.h>
+#include <xen/events.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/version.h>
 #include <xen/interface/physdev.h>
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 1573376..01a4dc0 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -5,6 +5,7 @@
 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
 #include <xen/interface/vcpu.h>
+#include <xen/events.h>
 
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 202d4c1..2368295 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -35,7 +35,6 @@ void xen_set_pat(u64);
 
 char * __init xen_memory_setup(void);
 void __init xen_arch_setup(void);
-void __init xen_init_IRQ(void);
 void xen_enable_sysenter(void);
 void xen_enable_syscall(void);
 void xen_vcpu_restore(void);
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 7da65d3..9b506b2 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -31,14 +31,16 @@
 #include <linux/irqnr.h>
 #include <linux/pci.h>
 
+#ifdef CONFIG_X86
 #include <asm/desc.h>
 #include <asm/ptrace.h>
 #include <asm/irq.h>
 #include <asm/idle.h>
 #include <asm/io_apic.h>
-#include <asm/sync_bitops.h>
 #include <asm/xen/page.h>
 #include <asm/xen/pci.h>
+#endif
+#include <asm/sync_bitops.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
 
@@ -50,6 +52,9 @@
 #include <xen/interface/event_channel.h>
 #include <xen/interface/hvm/hvm_op.h>
 #include <xen/interface/hvm/params.h>
+#include <xen/interface/physdev.h>
+#include <xen/interface/sched.h>
+#include <asm/hw_irq.h>
 
 /*
  * This lock protects updates to the following mapping and reference-count
@@ -834,6 +839,7 @@ int bind_evtchn_to_irq(unsigned int evtchn)
 		struct irq_info *info = info_for_irq(irq);
 		WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 	}
+	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
 
 out:
 	mutex_unlock(&irq_mapping_update_lock);
@@ -1377,7 +1383,9 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
+#ifdef CONFIG_X86
 	exit_idle();
+#endif
 	irq_enter();
 
 	__xen_evtchn_do_upcall();
@@ -1786,9 +1794,9 @@ void xen_callback_vector(void)
 void xen_callback_vector(void) {}
 #endif
 
-void __init xen_init_IRQ(void)
+void xen_init_IRQ(void)
 {
-	int i, rc;
+	int i;
 
 	evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
 				    GFP_KERNEL);
@@ -1804,6 +1812,7 @@ void __init xen_init_IRQ(void)
 
 	pirq_needs_eoi = pirq_needs_eoi_flag;
 
+#ifdef CONFIG_X86
 	if (xen_hvm_domain()) {
 		xen_callback_vector();
 		native_init_IRQ();
@@ -1811,6 +1820,7 @@ void __init xen_init_IRQ(void)
 		 * __acpi_register_gsi can point at the right function */
 		pci_xen_hvm_init();
 	} else {
+		int rc;
 		struct physdev_pirq_eoi_gmfn eoi_gmfn;
 
 		irq_ctx_init(smp_processor_id());
@@ -1826,4 +1836,6 @@ void __init xen_init_IRQ(void)
 		} else
 			pirq_needs_eoi = pirq_check_eoi_map;
 	}
+#endif
 }
+EXPORT_SYMBOL_GPL(xen_init_IRQ);
diff --git a/include/xen/events.h b/include/xen/events.h
index 04399b2..c6bfe01 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -109,4 +109,6 @@ int xen_irq_from_gsi(unsigned gsi);
 /* Determine whether to ignore this IRQ if it is passed to a guest. */
 int xen_test_irq_shared(int irq);
 
+/* initialize Xen IRQ subsystem */
+void xen_init_IRQ(void);
 #endif	/* _XEN_EVENTS_H */
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 16/24] xen/arm: implement alloc/free_xenballooned_pages with alloc_pages/kfree

Only until we get the balloon driver to work.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/xen/enlighten.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 60d6d36..1476b0b 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -121,6 +121,24 @@ int __init xen_guest_init(void)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xen_guest_init);
+
+/* XXX: only until balloon is properly working */
+int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem)
+{
+	*pages = alloc_pages(highmem ? GFP_HIGHUSER : GFP_KERNEL,
+			get_order(nr_pages));
+	if (*pages == NULL)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(alloc_xenballooned_pages);
+
+void free_xenballooned_pages(int nr_pages, struct page **pages)
+{
+	kfree(*pages);
+	*pages = NULL;
+}
+EXPORT_SYMBOL_GPL(free_xenballooned_pages);
 core_initcall(xen_guest_init);
 
 static irqreturn_t xen_arm_callback(int irq, void *arg)
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:33 UTC

head link

[PATCH 17/24] xen: allow privcmd for HVM guests

In order for privcmd mmap to work correctly, xen_remap_domain_mfn_range
needs to be implemented for HVM guests.
If it is not, mmap is going to fail later on.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 drivers/xen/privcmd.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index ccee0f1..85226cb 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -380,10 +380,6 @@ static struct vm_operations_struct privcmd_vm_ops = {
 
 static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	/* Unsupported for auto-translate guests. */
-	if (xen_feature(XENFEAT_auto_translated_physmap))
-		return -ENOSYS;
-
 	/* DONTCOPY is essential for Xen because copy_page_range doesn''t know
 	 * how to recreate these mappings */
 	vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 18/24] xen/arm: compile blkfront and blkback

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 drivers/block/xen-blkback/blkback.c  |    1 +
 include/xen/interface/io/protocols.h |    3 +++
 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c
b/drivers/block/xen-blkback/blkback.c
index 73f196c..63dd5b9 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -42,6 +42,7 @@
 
 #include <xen/events.h>
 #include <xen/page.h>
+#include <xen/xen.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include "common.h"
diff --git a/include/xen/interface/io/protocols.h
b/include/xen/interface/io/protocols.h
index 01fc8ae..0eafaf2 100644
--- a/include/xen/interface/io/protocols.h
+++ b/include/xen/interface/io/protocols.h
@@ -5,6 +5,7 @@
 #define XEN_IO_PROTO_ABI_X86_64     "x86_64-abi"
 #define XEN_IO_PROTO_ABI_IA64       "ia64-abi"
 #define XEN_IO_PROTO_ABI_POWERPC64  "powerpc64-abi"
+#define XEN_IO_PROTO_ABI_ARM        "arm-abi"
 
 #if defined(__i386__)
 # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_32
@@ -14,6 +15,8 @@
 # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_IA64
 #elif defined(__powerpc64__)
 # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_POWERPC64
+#elif defined(__arm__)
+# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_ARM
 #else
 # error arch fixup needed here
 #endif
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 19/24] xen/arm: compile netback

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/include/asm/xen/hypercall.h |   19 +++++++++++++++++++
 drivers/net/xen-netback/netback.c    |    1 +
 drivers/net/xen-netfront.c           |    1 +
 3 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/arch/arm/include/asm/xen/hypercall.h
b/arch/arm/include/asm/xen/hypercall.h
index 4ac0624..8a82325 100644
--- a/arch/arm/include/asm/xen/hypercall.h
+++ b/arch/arm/include/asm/xen/hypercall.h
@@ -47,4 +47,23 @@ unsigned long HYPERVISOR_hvm_op(int op, void *arg);
 int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
 int HYPERVISOR_physdev_op(int cmd, void *arg);
 
+static inline void
+MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
+			unsigned int new_val, unsigned long flags)
+{
+	BUG();
+}
+
+static inline void
+MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
+		 int count, int *success_count, domid_t domid)
+{
+	BUG();
+}
+
+static inline int
+HYPERVISOR_multicall(void *call_list, int nr_calls)
+{
+	BUG();
+}
 #endif /* _ASM_ARM_XEN_HYPERCALL_H */
diff --git a/drivers/net/xen-netback/netback.c
b/drivers/net/xen-netback/netback.c
index f4a6fca..ab4f81c 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -40,6 +40,7 @@
 
 #include <net/tcp.h>
 
+#include <xen/xen.h>
 #include <xen/events.h>
 #include <xen/interface/memory.h>
 
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 3089990..bf4ba2b 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -43,6 +43,7 @@
 #include <linux/slab.h>
 #include <net/ip.h>
 
+#include <asm/xen/page.h>
 #include <xen/xen.h>
 #include <xen/xenbus.h>
 #include <xen/events.h>
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 20/24] xen: update xen_add_to_physmap interface

Update struct xen_add_to_physmap to be in sync with Xen''s version of
the
structure.
The size field was introduced by:

changeset:   24164:707d27fe03e7
user:        Jean Guyader
<jean.guyader-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
date:        Fri Nov 18 13:42:08 2011 +0000
summary:     mm: New XENMEM space, XENMAPSPACE_gmfn_range

According to the comment:

"This new field .size is located in the 16 bits padding between .domid
and .space in struct xen_add_to_physmap to stay compatible with older
versions."

This is not true on ARM where there is not padding, but it is valid on
X86, so introducing size is safe on X86 and it is going to fix the
interace for ARM.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 include/xen/interface/memory.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index abbbff0..d8e33a9 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -163,6 +163,9 @@ struct xen_add_to_physmap {
     /* Which domain to change the mapping for. */
     domid_t domid;
 
+    /* Number of pages to go through for gmfn_range */
+    uint16_t    size;
+
     /* Source mapping space. */
 #define XENMAPSPACE_shared_info 0 /* shared info page */
 #define XENMAPSPACE_grant_table 1 /* grant table page */
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/mach-vexpress/v2m.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index fde26ad..dee1451 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -637,16 +637,17 @@ static void __init v2m_dt_timer_init(void)
 	node = of_find_compatible_node(NULL, NULL, "arm,sp810");
 	v2m_sysctl_init(of_iomap(node, 0));
 
-	err = of_property_read_string(of_aliases, "arm,v2m_timer",
&path);
-	if (WARN_ON(err))
-		return;
-	node = of_find_node_by_path(path);
-	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
 	if (arch_timer_of_register() != 0)
 		twd_local_timer_of_register();
 
 	if (arch_timer_sched_clock_init() != 0)
 		versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ, 24000000);
+
+	err = of_property_read_string(of_aliases, "arm,v2m_timer",
&path);
+	if (WARN_ON(err))
+		return;
+	node = of_find_node_by_path(path);
+	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
 }
 
 static struct sys_timer v2m_dt_timer = {
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 22/24] ARM: enable earlyprintk=xen

From: Ian Campbell <ian.campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>

Currently ARM setup_early_printk does not support alternative early
consoles and it always registers early_console only.

This patch adds support for xenboot_console.

Signed-off-by: Ian Campbell
<ian.campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/kernel/early_printk.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kernel/early_printk.c b/arch/arm/kernel/early_printk.c
index 85aa2b2..eecfa21 100644
--- a/arch/arm/kernel/early_printk.c
+++ b/arch/arm/kernel/early_printk.c
@@ -11,6 +11,8 @@
 #include <linux/kernel.h>
 #include <linux/console.h>
 #include <linux/init.h>
+#include <linux/string.h>
+#include <xen/hvc-console.h>
 
 extern void printch(int);
 
@@ -50,7 +52,14 @@ asmlinkage void early_printk(const char *fmt, ...)
 
 static int __init setup_early_printk(char *buf)
 {
-	register_console(&early_console);
+	if (!buf || !strncmp(buf, "serial", 6))
+		register_console(&early_console);
+
+#ifdef CONFIG_HVC_XEN
+	if (!strncmp(buf, "xen", 3))
+		register_console(&xenboot_console);
+#endif
+
 	return 0;
 }
 
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 23/24] hvc_xen: allow dom0_write_console for HVM guests

On ARM all guests are HVM guests, including Dom0.
Allow dom0_write_console to be called by an HVM domain.

Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 drivers/tty/hvc/hvc_xen.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 3c04fb8..949edc2 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -616,12 +616,9 @@ static void xenboot_write_console(struct console *console,
const char *string,
 	unsigned int linelen, off = 0;
 	const char *pos;
 
-	if (!xen_pv_domain())
-		return;
-
 	dom0_write_console(0, string, len);
 
-	if (xen_initial_domain())
+	if (!xen_pv_domain())
 		return;
 
 	domU_write_console(0, "(early) ", 8);
-- 
1.7.2.5

Stefano Stabellini

2012-Jul-26 15:34 UTC

head link

[PATCH 24/24] [HACK] xen/arm: implement xen_remap_domain_mfn_range

From: Ian Campbell <Ian.Campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>

Do not apply!

This is a simple, hacky implementation of xen_remap_domain_mfn_range,
using XENMAPSPACE_gmfn_foreign.

It should use same interface as hybrid x86.

Signed-off-by: Ian Campbell
<Ian.Campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
---
 arch/arm/xen/enlighten.c       |   79 +++++++++++++++++++++++++++++++++++++++-
 drivers/xen/privcmd.c          |   16 +++++----
 drivers/xen/xenfs/super.c      |    7 ++++
 include/xen/interface/memory.h |   10 ++++--
 4 files changed, 101 insertions(+), 11 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 1476b0b..7092015 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -16,6 +16,10 @@
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
+#include <linux/mm.h>
+#include <linux/ioport.h>
+
+#include <asm/pgtable.h>
 
 struct start_info _xen_start_info;
 struct start_info *xen_start_info = &_xen_start_info;
@@ -38,12 +42,85 @@ EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
 
 static __read_mostly int xen_events_irq = -1;
 
+#define FOREIGN_MAP_BUFFER 0x90000000UL
+#define FOREIGN_MAP_BUFFER_SIZE 0x10000000UL
+struct resource foreign_map_resource = {
+	.start = FOREIGN_MAP_BUFFER,
+	.end = FOREIGN_MAP_BUFFER + FOREIGN_MAP_BUFFER_SIZE,
+	.name = "Xen foreign map buffer",
+	.flags = 0,
+};
+
+static unsigned long foreign_map_buffer_pfn = FOREIGN_MAP_BUFFER >>
PAGE_SHIFT;
+
+struct remap_data {
+	struct mm_struct *mm;
+	unsigned long mfn;
+	pgprot_t prot;
+};
+
+static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
+				 unsigned long addr, void *data)
+{
+	struct remap_data *rmd = data;
+	pte_t pte = pfn_pte(rmd->mfn, rmd->prot);
+
+	if (rmd->mfn < 0x90010)
+		pr_crit("%s: ptep %p addr %#lx => %#x / %#lx\n",
+		       __func__, ptep, addr, pte_val(pte), rmd->mfn);
+
+	set_pte_at(rmd->mm, addr, ptep, pte);
+
+	rmd->mfn++;
+	return 0;
+}
+
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
 			       unsigned long mfn, int nr,
 			       pgprot_t prot, unsigned domid)
 {
-	return -ENOSYS;
+	int i, rc = 0;
+	struct remap_data rmd = {
+		.mm = vma->vm_mm,
+		.prot = prot,
+	};
+	struct xen_add_to_physmap xatp = {
+		.domid = DOMID_SELF,
+		.space = XENMAPSPACE_gmfn_foreign,
+
+		.foreign_domid = domid,
+	};
+
+	if (foreign_map_buffer_pfn + nr > ((FOREIGN_MAP_BUFFER +
+					FOREIGN_MAP_BUFFER_SIZE)>>PAGE_SHIFT)) {
+		pr_crit("RAM out of foreign map buffers...\n");
+		return -EBUSY;
+	}
+
+	for (i = 0; i < nr; i++) {
+		xatp.idx = mfn + i;
+		xatp.gpfn = foreign_map_buffer_pfn + i;
+		rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
+		if (rc != 0) {
+			pr_crit("foreign map add_to_physmap failed, err=%d\n", rc);
+			goto out;
+		}
+	}
+
+	rmd.mfn = foreign_map_buffer_pfn;
+	rc = apply_to_page_range(vma->vm_mm,
+				 addr,
+				 (unsigned long)nr << PAGE_SHIFT,
+				 remap_area_mfn_pte_fn, &rmd);
+	if (rc != 0) {
+		pr_crit("apply_to_page_range failed rc=%d\n", rc);
+		goto out;
+	}
+
+	foreign_map_buffer_pfn += nr;
+out:
+	return rc;
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
 
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 85226cb..3e15c22 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -20,6 +20,8 @@
 #include <linux/pagemap.h>
 #include <linux/seq_file.h>
 #include <linux/miscdevice.h>
+#include <linux/resource.h>
+#include <linux/ioport.h>
 
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
@@ -196,9 +198,6 @@ static long privcmd_ioctl_mmap(void __user *udata)
 	LIST_HEAD(pagelist);
 	struct mmap_mfn_state state;
 
-	if (!xen_initial_domain())
-		return -EPERM;
-
 	if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
 		return -EFAULT;
 
@@ -286,9 +285,6 @@ static long privcmd_ioctl_mmap_batch(void __user *udata)
 	LIST_HEAD(pagelist);
 	struct mmap_batch_state state;
 
-	if (!xen_initial_domain())
-		return -EPERM;
-
 	if (copy_from_user(&m, udata, sizeof(m)))
 		return -EFAULT;
 
@@ -365,6 +361,11 @@ static long privcmd_ioctl(struct file *file,
 	return ret;
 }
 
+static void privcmd_close(struct vm_area_struct *vma)
+{
+	/* TODO: unmap VMA */
+}
+
 static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx,
uv=%p\n",
@@ -375,7 +376,8 @@ static int privcmd_fault(struct vm_area_struct *vma, struct
vm_fault *vmf)
 }
 
 static struct vm_operations_struct privcmd_vm_ops = {
-	.fault = privcmd_fault
+	.fault = privcmd_fault,
+	.close = privcmd_close,
 };
 
 static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index a84b53c..edbe22f 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/magic.h>
+#include <linux/ioport.h>
 
 #include <xen/xen.h>
 
@@ -80,6 +81,8 @@ static const struct file_operations capabilities_file_ops = {
 	.llseek = default_llseek,
 };
 
+extern struct resource foreign_map_resource;
+
 static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	static struct tree_descr xenfs_files[] = {
@@ -100,6 +103,10 @@ static int xenfs_fill_super(struct super_block *sb, void
*data, int silent)
 				  &xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR);
 		xenfs_create_file(sb, sb->s_root, "xsd_port",
 				  &xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR);
+		rc = request_resource(&iomem_resource, &foreign_map_resource);
+		if (rc < 0)
+			pr_crit("failed to register foreign map resource\n");
+		rc = 0; /* ignore */
 	}
 
 	return rc;
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index d8e33a9..ec68945 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -167,9 +167,13 @@ struct xen_add_to_physmap {
     uint16_t    size;
 
     /* Source mapping space. */
-#define XENMAPSPACE_shared_info 0 /* shared info page */
-#define XENMAPSPACE_grant_table 1 /* grant table page */
-    unsigned int space;
+#define XENMAPSPACE_shared_info  0 /* shared info page */
+#define XENMAPSPACE_grant_table  1 /* grant table page */
+#define XENMAPSPACE_gmfn         2 /* GMFN */
+#define XENMAPSPACE_gmfn_range   3 /* GMFN range */
+#define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another guest */
+    uint16_t space;
+    domid_t foreign_domid; /* IFF gmfn_foreign */
 
     /* Index into source mapping space. */
     unsigned long idx;
-- 
1.7.2.5

Konrad Rzeszutek Wilk

2012-Jul-26 16:30 UTC

head link

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

On Thu, Jul 26, 2012 at 04:33:43PM +0100, Stefano Stabellini
wrote:> - Basic hypervisor.h and interface.h definitions.
> - Skelethon enlighten.c, set xen_start_info to an empty struct.
Skeleton
> - Do not limit xen_initial_domain to PV guests.
Better wording: Make xen_initial_domain dependent on the SIF_PRIVILIGED_BIT.

Which reminds me - what about PV guests that do PCI passthrough. Aren''t
they "more" priviligied than normal PV guests? Or not
really?> 
> The new code only compiles when CONFIG_XEN is set, that is going to be
> added to arch/arm/Kconfig in a later patch.
s/later patch/<name of patch>/
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/Makefile                     |    1 +
>  arch/arm/include/asm/hypervisor.h     |    6 +++
>  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
>  arch/arm/include/asm/xen/interface.h  |   64
+++++++++++++++++++++++++++++++++
>  arch/arm/xen/Makefile                 |    1 +
>  arch/arm/xen/enlighten.c              |   35 ++++++++++++++++++
>  include/xen/xen.h                     |    2 +-
>  7 files changed, 127 insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/include/asm/hypervisor.h
>  create mode 100644 arch/arm/include/asm/xen/hypervisor.h
>  create mode 100644 arch/arm/include/asm/xen/interface.h
>  create mode 100644 arch/arm/xen/Makefile
>  create mode 100644 arch/arm/xen/enlighten.c
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 0298b00..70aaa82 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -246,6 +246,7 @@ endif
>  core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
>  core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
>  core-$(CONFIG_VFP)		+= arch/arm/vfp/
> +core-$(CONFIG_XEN)		+= arch/arm/xen/
>  
>  # If we have a machine-specific directory, then include it in the build.
>  core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
> diff --git a/arch/arm/include/asm/hypervisor.h
b/arch/arm/include/asm/hypervisor.h
> new file mode 100644
> index 0000000..b90d9e5
> --- /dev/null
> +++ b/arch/arm/include/asm/hypervisor.h
> @@ -0,0 +1,6 @@
> +#ifndef _ASM_ARM_HYPERVISOR_H
> +#define _ASM_ARM_HYPERVISOR_H
> +
> +#include <asm/xen/hypervisor.h>
> +
> +#endif
> diff --git a/arch/arm/include/asm/xen/hypervisor.h
b/arch/arm/include/asm/xen/hypervisor.h
> new file mode 100644
> index 0000000..d7ab99a
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/hypervisor.h
> @@ -0,0 +1,19 @@
> +#ifndef _ASM_ARM_XEN_HYPERVISOR_H
> +#define _ASM_ARM_XEN_HYPERVISOR_H
> +
> +extern struct shared_info *HYPERVISOR_shared_info;
> +extern struct start_info *xen_start_info;
> +
> +/* Lazy mode for batching updates / context switch */
> +enum paravirt_lazy_mode {
> +	PARAVIRT_LAZY_NONE,
> +	PARAVIRT_LAZY_MMU,
> +	PARAVIRT_LAZY_CPU,
> +};
> +
> +static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
> +{
> +	return PARAVIRT_LAZY_NONE;
> +}
> +
> +#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
> diff --git a/arch/arm/include/asm/xen/interface.h
b/arch/arm/include/asm/xen/interface.h
> new file mode 100644
> index 0000000..6c3ab59
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/interface.h
> @@ -0,0 +1,64 @@
>
+/******************************************************************************
> + * Guest OS interface to ARM Xen.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix,
2011
2012
> + */
> +
> +#ifndef _ASM_ARM_XEN_INTERFACE_H
> +#define _ASM_ARM_XEN_INTERFACE_H
> +
> +#include <linux/types.h>
> +
> +#define __DEFINE_GUEST_HANDLE(name, type) \
> +	typedef type * __guest_handle_ ## name
> +
> +#define DEFINE_GUEST_HANDLE_STRUCT(name) \
> +	__DEFINE_GUEST_HANDLE(name, struct name)
> +#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
> +#define GUEST_HANDLE(name)        __guest_handle_ ## name
> +
> +#define set_xen_guest_handle(hnd, val)			\
> +	do {						\
> +		if (sizeof(hnd) == 8)			\
> +			*(uint64_t *)&(hnd) = 0;	\
> +		(hnd) = val;				\
> +	} while (0)
> +
> +#ifndef __ASSEMBLY__
> +/* Guest handles for primitive C types. */
> +__DEFINE_GUEST_HANDLE(uchar, unsigned char);
> +__DEFINE_GUEST_HANDLE(uint,  unsigned int);
> +__DEFINE_GUEST_HANDLE(ulong, unsigned long);
> +DEFINE_GUEST_HANDLE(char);
> +DEFINE_GUEST_HANDLE(int);
> +DEFINE_GUEST_HANDLE(long);
> +DEFINE_GUEST_HANDLE(void);
> +DEFINE_GUEST_HANDLE(uint64_t);
> +DEFINE_GUEST_HANDLE(uint32_t);
> +
> +/* Maximum number of virtual CPUs in multi-processor guests. */
> +#define MAX_VIRT_CPUS 1
> +
> +struct arch_vcpu_info { };
> +struct arch_shared_info { };
> +
> +/* XXX: Move pvclock definitions some place arch independent */
> +struct pvclock_vcpu_time_info {
> +	u32   version;
> +	u32   pad0;
> +	u64   tsc_timestamp;
> +	u64   system_time;
> +	u32   tsc_to_system_mul;
> +	s8    tsc_shift;
> +	u8    flags;
> +	u8    pad[2];
> +} __attribute__((__packed__)); /* 32 bytes */
> +
> +struct pvclock_wall_clock {
> +	u32   version;
> +	u32   sec;
> +	u32   nsec;
> +} __attribute__((__packed__));
That is weird. It is 4+4+4 = 12 bytes? Don''t you want it to be 16
bytes?
> +#endif
> +
> +#endif /* _ASM_ARM_XEN_INTERFACE_H */
> diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> new file mode 100644
> index 0000000..0bad594
> --- /dev/null
> +++ b/arch/arm/xen/Makefile
> @@ -0,0 +1 @@
> +obj-y		:= enlighten.o
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> new file mode 100644
> index 0000000..d27c2a6
> --- /dev/null
> +++ b/arch/arm/xen/enlighten.c
> @@ -0,0 +1,35 @@
> +#include <xen/xen.h>
> +#include <xen/interface/xen.h>
> +#include <xen/interface/memory.h>
> +#include <xen/platform_pci.h>
> +#include <asm/xen/hypervisor.h>
> +#include <asm/xen/hypercall.h>
> +#include <linux/module.h>
> +
> +struct start_info _xen_start_info;
> +struct start_info *xen_start_info = &_xen_start_info;
> +EXPORT_SYMBOL_GPL(xen_start_info);
> +
> +enum xen_domain_type xen_domain_type = XEN_NATIVE;
> +EXPORT_SYMBOL_GPL(xen_domain_type);
> +
> +struct shared_info xen_dummy_shared_info;
> +struct shared_info *HYPERVISOR_shared_info = (void
*)&xen_dummy_shared_info;
> +
> +DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
> +
> +/* XXX: to be removed */
In this patch series later on? Or just when you try to collapse the x86 and arm
variant
together?
> +__read_mostly int xen_have_vector_callback;
> +EXPORT_SYMBOL_GPL(xen_have_vector_callback);
> +
> +int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
> +EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
> +
> +int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> +			       unsigned long addr,
> +			       unsigned long mfn, int nr,
> +			       pgprot_t prot, unsigned domid)
> +{
> +	return -ENOSYS;
> +}
> +EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> diff --git a/include/xen/xen.h b/include/xen/xen.h
> index a164024..2c0d3a5 100644
> --- a/include/xen/xen.h
> +++ b/include/xen/xen.h
> @@ -23,7 +23,7 @@ extern enum xen_domain_type xen_domain_type;
>  #include <xen/interface/xen.h>
>  #include <asm/xen/hypervisor.h>
>  
> -#define xen_initial_domain()	(xen_pv_domain() && \
> +#define xen_initial_domain()	(xen_domain() && \
>  				 xen_start_info->flags & SIF_INITDOMAIN)
>  #else  /* !CONFIG_XEN_DOM0 */
>  #define xen_initial_domain()	(0)
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Konrad Rzeszutek Wilk

2012-Jul-26 16:33 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Thu, Jul 26, 2012 at 04:33:44PM +0100, Stefano Stabellini
wrote:> Use r12 to pass the hypercall number to the hypervisor.
> 
> We need a register to pass the hypercall number because we might not
> know it at compile time and HVC only takes an immediate argument.
> 
> Among the available registers r12 seems to be the best choice because it
> is defined as "intra-procedure call scratch register".
> 
> Use the ISS to pass an hypervisor specific tag.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/include/asm/xen/hypercall.h |   50 ++++++++++++++++++++++++++
>  arch/arm/xen/Makefile                |    2 +-
>  arch/arm/xen/hypercall.S             |   65
++++++++++++++++++++++++++++++++++
>  3 files changed, 116 insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/include/asm/xen/hypercall.h
>  create mode 100644 arch/arm/xen/hypercall.S
> 
> diff --git a/arch/arm/include/asm/xen/hypercall.h
b/arch/arm/include/asm/xen/hypercall.h
> new file mode 100644
> index 0000000..4ac0624
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/hypercall.h
> @@ -0,0 +1,50 @@
>
+/******************************************************************************
> + * hypercall.h
> + *
> + * Linux-specific hypervisor handling.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix,
2012
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation; or, when distributed
> + * separately from the Linux kernel or incorporated into other
> + * software packages, subject to the following license:
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
copy
> + * of this source file (the "Software"), to deal in the Software
without
> + * restriction, including without limitation the rights to use, copy,
modify,
> + * merge, publish, distribute, sublicense, and/or sell copies of the
Software,
> + * and to permit persons to whom the Software is furnished to do so,
subject to
> + * the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included
in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#ifndef _ASM_ARM_XEN_HYPERCALL_H
> +#define _ASM_ARM_XEN_HYPERCALL_H
> +
> +#include <xen/interface/xen.h>
> +
> +long privcmd_call(unsigned call, unsigned long a1,
> +		unsigned long a2, unsigned long a3,
> +		unsigned long a4, unsigned long a5);
> +int HYPERVISOR_xen_version(int cmd, void *arg);
> +int HYPERVISOR_console_io(int cmd, int count, char *str);
> +int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int
count);
> +int HYPERVISOR_sched_op(int cmd, void *arg);
> +int HYPERVISOR_event_channel_op(int cmd, void *arg);
> +unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> +int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> +int HYPERVISOR_physdev_op(int cmd, void *arg);
> +
> +#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> index 0bad594..b9d6acc 100644
> --- a/arch/arm/xen/Makefile
> +++ b/arch/arm/xen/Makefile
> @@ -1 +1 @@
> -obj-y		:= enlighten.o
> +obj-y		:= enlighten.o hypercall.o
> diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
> new file mode 100644
> index 0000000..038cc5b
> --- /dev/null
> +++ b/arch/arm/xen/hypercall.S
> @@ -0,0 +1,65 @@
>
+/******************************************************************************
> + * hypercall.S
> + *
> + * Xen hypercall wrappers
> + *
> + * The Xen hypercall calling convention is very similar to the ARM
> + * procedure calling convention: the first paramter is passed in r0, the
> + * second in r1, the third in r2 and the third in r3. Considering that
I think you meant ''and the fourth in r3''.

So where does the similarity end?  Just in that we use r12?
> + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed
> + * in r4, differently from the procedure calling convention of using the
> + * stack for that case.
> + *
> + * The hypercall number is passed in r12.
> + *
> + * The return value is in r0.
> + *
> + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> + * hypercall tag.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix,
2012
> + */
> +
> +#include <linux/linkage.h>
> +#include <asm/assembler.h>
> +#include <xen/interface/xen.h>
> +
> +
> +/* HVC 0xEA1 */
> +#ifdef CONFIG_THUMB2_KERNEL
> +#define xen_hvc .word 0xf7e08ea1
> +#else
> +#define xen_hvc .word 0xe140ea71
> +#endif
> +
> +/* We need to save and restore r4, because Xen clobbers it. */
Hmm, the comment says r4, but right below I see r12?
Should this comment be by ''privcmd_call''?
> +#define HYPERCALL(hypercall)			\
> +ENTRY(HYPERVISOR_##hypercall)			\
> +	mov r12, #__HYPERVISOR_##hypercall;	\
> +	xen_hvc;							\
> +	mov pc, lr;							\
> +ENDPROC(HYPERVISOR_##hypercall)
> +
> +                .text
> +
> +HYPERCALL(xen_version);
> +HYPERCALL(console_io);
> +HYPERCALL(grant_table_op);
> +HYPERCALL(sched_op);
> +HYPERCALL(event_channel_op);
> +HYPERCALL(hvm_op);
> +HYPERCALL(memory_op);
> +HYPERCALL(physdev_op);
> +
> +ENTRY(privcmd_call)
> +	stmdb	sp!, {r4}
> +	mov r12, r0
> +	mov r0, r1
> +	mov r1, r2
> +	mov r2, r3
> +	ldr r3, [sp, #8]
> +	ldr r4, [sp, #4]
> +	xen_hvc
> +	pop {r4}
> +	mov pc, lr
> +ENDPROC(privcmd_call);
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Konrad Rzeszutek Wilk

2012-Jul-26 16:36 UTC

head link

Re: [Xen-devel] [PATCH 03/24] xen/arm: page.h definitions

On Thu, Jul 26, 2012 at 04:33:45PM +0100, Stefano Stabellini
wrote:> ARM Xen guests always use paging in hardware, like PV on HVM guests in
> the X86 world.
Nice, so no dealing with the P2M at all in the guest?
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/include/asm/xen/page.h |   77
+++++++++++++++++++++++++++++++++++++++
>  1 files changed, 77 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/include/asm/xen/page.h
> 
> diff --git a/arch/arm/include/asm/xen/page.h
b/arch/arm/include/asm/xen/page.h
> new file mode 100644
> index 0000000..6cfe9a1
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/page.h
> @@ -0,0 +1,77 @@
> +#ifndef _ASM_ARM_XEN_PAGE_H
> +#define _ASM_ARM_XEN_PAGE_H
> +
> +#include <asm/page.h>
> +#include <linux/pfn.h>
> +#include <linux/types.h>
> +#include <asm/pgtable.h>
> +#include <xen/interface/grant_table.h>
I don''t if it makes such a difference, but putting the headers in
sorted
order is sometimes nicer than just randomly.. But that might be just
me liking an orderly world nowadays :-)
> +
> +#define pfn_to_mfn(pfn)			(pfn)
> +#define phys_to_machine_mapping_valid	(1)
> +#define mfn_to_pfn(mfn)			(mfn)
> +#define mfn_to_virt(m)			(__va(mfn_to_pfn(m) << PAGE_SHIFT))
> +
> +#define pte_mfn	    pte_pfn
> +#define mfn_pte	    pfn_pte
> +
> +/* Xen machine address */
> +typedef struct xmaddr {
> +	phys_addr_t maddr;
> +} xmaddr_t;
> +
> +/* Xen pseudo-physical address */
> +typedef struct xpaddr {
> +	phys_addr_t paddr;
> +} xpaddr_t;
> +
> +#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
> +#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })
> +
> +static inline xmaddr_t phys_to_machine(xpaddr_t phys)
> +{
> +	unsigned offset = phys.paddr & ~PAGE_MASK;
> +	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
> +}
> +
> +static inline xpaddr_t machine_to_phys(xmaddr_t machine)
> +{
> +	unsigned offset = machine.maddr & ~PAGE_MASK;
> +	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
> +}
> +/* VIRT <-> MACHINE conversion */
> +#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
> +#define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
> +#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
> +#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))
> +
> +static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
> +{
> +	/* XXX: assuming it is mapped in the kernel 1:1 */
> +	return virt_to_machine(vaddr);
> +}
> +
> +/* XXX: this shouldn''t be here */
So why is it here?
> +static inline pte_t *lookup_address(unsigned long address, unsigned int
*level)
> +{
> +	BUG();
> +	return NULL;
> +}
> +
> +static inline int m2p_add_override(unsigned long mfn, struct page *page,
> +		struct gnttab_map_grant_ref *kmap_op)
> +{
> +	return 0;
> +}
> +
> +static inline int m2p_remove_override(struct page *page, bool clear_pte)
> +{
> +	return 0;
> +}
> +
> +static inline bool set_phys_to_machine(unsigned long pfn, unsigned long
mfn)
> +{
> +	BUG();
> +	return false;
> +}
> +#endif /* _ASM_ARM_XEN_PAGE_H */
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Konrad Rzeszutek Wilk

2012-Jul-26 16:37 UTC

head link

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

On Thu, Jul 26, 2012 at 04:33:46PM +0100, Stefano Stabellini
wrote:> sync_bitops functions are equivalent to the SMP implementation of the
> original functions, independently from CONFIG_SMP being defined.
So why can''t the code be changed to use that? Is it that
the _set_bit, _clear_bit, etc are not available with !CONFIG_SMP?
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/include/asm/sync_bitops.h |   17 +++++++++++++++++
>  1 files changed, 17 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/include/asm/sync_bitops.h
> 
> diff --git a/arch/arm/include/asm/sync_bitops.h
b/arch/arm/include/asm/sync_bitops.h
> new file mode 100644
> index 0000000..d975092903
> --- /dev/null
> +++ b/arch/arm/include/asm/sync_bitops.h
> @@ -0,0 +1,17 @@
> +#ifndef __ASM_SYNC_BITOPS_H__
> +#define __ASM_SYNC_BITOPS_H__
> +
> +#include <asm/bitops.h>
> +#include <asm/system.h>
> +
> +#define sync_set_bit(nr, p)		_set_bit(nr, p)
> +#define sync_clear_bit(nr, p)		_clear_bit(nr, p)
> +#define sync_change_bit(nr, p)		_change_bit(nr, p)
> +#define sync_test_and_set_bit(nr, p)	_test_and_set_bit(nr, p)
> +#define sync_test_and_clear_bit(nr, p)	_test_and_clear_bit(nr, p)
> +#define sync_test_and_change_bit(nr, p)	_test_and_change_bit(nr, p)
> +#define sync_test_bit(nr, addr)		test_bit(nr, addr)
> +#define sync_cmpxchg			cmpxchg
> +
> +
> +#endif
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

David Vrabel

2012-Jul-26 16:56 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On 26/07/12 16:33, Stefano Stabellini wrote:> 
> + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> + * hypercall tag.
Is this number, 0xea1, assigned to Xen by some external body?

David

Stefano Stabellini

2012-Jul-26 17:19 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Thu, 26 Jul 2012, David Vrabel wrote:> On 26/07/12 16:33, Stefano Stabellini wrote:
> > 
> > + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> > + * hypercall tag.
> 
> Is this number, 0xea1, assigned to Xen by some external body?
I am not aware of any "external body" that could assign us such a
number
but it is specified in the Xen hypercall calling convention, documented
here:

http://xenbits.xensource.com/hg/xen-unstable.hg/file/663eb766cdde/xen/include/public/arch-arm.h

Christopher Covington

2012-Jul-26 19:19 UTC

head link

Re: [PATCH 02/24] xen/arm: hypercalls

Hi Stefano,

On 07/26/2012 11:33 AM, Stefano Stabellini wrote:> Use r12 to pass the hypercall number to the hypervisor.
> 
> We need a register to pass the hypercall number because we might not
> know it at compile time and HVC only takes an immediate argument.
You''re not going to JIT assemble the appropriate HVC instruction? Darn.

How many call numbers are there, though? 8? It seems like it''d be
reasonable to take the approach that seems to be favored for MRC/MCR
instructions, using a function containing switch statement that chooses
between several inline assembly instructions based off an enum passed to
the function. See for example arch_timer_reg_read in
arch/arm/kernel/arch_timer.c.

Regards,
Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Jan Beulich

2012-Jul-27 06:57 UTC

head link

Re: [Xen-devel] [PATCH 06/24] xen: missing includes

>>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> --- a/include/xen/interface/xen.h
> +++ b/include/xen/interface/xen.h
> @@ -10,7 +10,10 @@
>  #define __XEN_PUBLIC_XEN_H__
>  
>  #include <asm/xen/interface.h>
> +#include <linux/types.h>
> +#ifdef CONFIG_X86
>  #include <asm/pvclock-abi.h>
> +#endif
Rather than hacking around this, why not clean it up:
asm/pvclock-abi.h clearly isn''t intended to be included here
(from the perspective of the origin of xen/interface/xen.h, at
least), nor is linux/types.h.

Or if it is really needed to deviate from the original header in
this respect, then clearly the inclusion ought to not be arch
specific or be moved to an arch specific header.

Jan
>  
>  /*
>   * XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS).

Jan Beulich

2012-Jul-27 07:01 UTC

head link

Re: [Xen-devel] [PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM

>>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> --- a/drivers/xen/Makefile
> +++ b/drivers/xen/Makefile
> @@ -1,11 +1,15 @@
> -obj-y	+= grant-table.o features.o events.o manage.o balloon.o
> +ifneq ($(CONFIG_ARM),y)
> +obj-y	+= manage.o balloon.o
While I assume that this part (and the cpu_hotplug one below) is
temporary, ...
> +obj-$(CONFIG_XEN_DOM0)			+= pci.o acpi.o
... at least this one should imo be solved with a proper long term
mechanism, i.e. the usual var-$(CONFIG_...) approach, i.e.

dom0-$(CONFIG_PCI) := pci.o
dom0-$(CONFIG_ACPI) := acpi.o
obj-$(CONFIG_XEN_DOM0)			+= $(dom0-y)

Jan
> +obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
> +endif
> +obj-y	+= grant-table.o features.o events.o
>  obj-y	+= xenbus/
>  
>  nostackp := $(call cc-option, -fno-stack-protector)
>  CFLAGS_features.o			:= $(nostackp)
>  
>  obj-$(CONFIG_BLOCK)			+= biomerge.o
> -obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
>  obj-$(CONFIG_XEN_XENCOMM)		+= xencomm.o
>  obj-$(CONFIG_XEN_BALLOON)		+= xen-balloon.o
>  obj-$(CONFIG_XEN_SELFBALLOONING)	+= xen-selfballoon.o
> @@ -17,7 +21,6 @@ obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
>  obj-$(CONFIG_XEN_PVHVM)			+= platform-pci.o
>  obj-$(CONFIG_XEN_TMEM)			+= tmem.o
>  obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o
> -obj-$(CONFIG_XEN_DOM0)			+= pci.o acpi.o
>  obj-$(CONFIG_XEN_PCIDEV_BACKEND)	+= xen-pciback/
>  obj-$(CONFIG_XEN_PRIVCMD)		+= xen-privcmd.o
>  obj-$(CONFIG_XEN_ACPI_PROCESSOR)	+= xen-acpi-processor.o
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org 
> http://lists.xen.org/xen-devel

Jan Beulich

2012-Jul-27 07:04 UTC

head link

Re: [Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

>>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> In order for privcmd mmap to work correctly, xen_remap_domain_mfn_range
> needs to be implemented for HVM guests.
> If it is not, mmap is going to fail later on.
Somehow, for me at least, this description doesn''t connect to the
actual change.
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  drivers/xen/privcmd.c |    4 ----
>  1 files changed, 0 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> index ccee0f1..85226cb 100644
> --- a/drivers/xen/privcmd.c
> +++ b/drivers/xen/privcmd.c
> @@ -380,10 +380,6 @@ static struct vm_operations_struct privcmd_vm_ops = {
>  
>  static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	/* Unsupported for auto-translate guests. */
> -	if (xen_feature(XENFEAT_auto_translated_physmap))
> -		return -ENOSYS;
> -
Is this safe on x86?

Jan
>  	/* DONTCOPY is essential for Xen because copy_page_range doesn''t
know
>  	 * how to recreate these mappings */
>  	vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;

Ian Campbell

2012-Jul-27 09:00 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Thu, 2012-07-26 at 17:56 +0100, David Vrabel wrote:> On 26/07/12 16:33, Stefano Stabellini wrote:
> > 
> > + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> > + * hypercall tag.
> 
> Is this number, 0xea1, assigned to Xen by some external body?
The value and semantics of the hvc instructions immediate operand is
entirely up to the hypervisor authors. We could have chosen 0 or some
random number, we went for the latter because it increases the chances,
by some tiny amount, that we won''t clash with some other hypervisors
ABI
which makes supporting "foreign" guests that bit easier should it even
come to it.

IOW it''s arbitrary in the same way that a Linux system calls used to
use
int 0x80.

Ian.

Ian Campbell

2012-Jul-27 09:17 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Thu, 2012-07-26 at 17:33 +0100, Konrad Rzeszutek Wilk
wrote:> On Thu, Jul 26, 2012 at 04:33:44PM +0100, Stefano Stabellini wrote:
> > Use r12 to pass the hypercall number to the hypervisor.
> > 
> > We need a register to pass the hypercall number because we might not
> > know it at compile time and HVC only takes an immediate argument.
> > 
> > Among the available registers r12 seems to be the best choice because
it
> > is defined as "intra-procedure call scratch register".
> > 
> > Use the ISS to pass an hypervisor specific tag.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/include/asm/xen/hypercall.h |   50
++++++++++++++++++++++++++
> >  arch/arm/xen/Makefile                |    2 +-
> >  arch/arm/xen/hypercall.S             |   65
++++++++++++++++++++++++++++++++++
> >  3 files changed, 116 insertions(+), 1 deletions(-)
> >  create mode 100644 arch/arm/include/asm/xen/hypercall.h
> >  create mode 100644 arch/arm/xen/hypercall.S
> > 
> > diff --git a/arch/arm/include/asm/xen/hypercall.h
b/arch/arm/include/asm/xen/hypercall.h
> > new file mode 100644
> > index 0000000..4ac0624
> > --- /dev/null
> > +++ b/arch/arm/include/asm/xen/hypercall.h
> > @@ -0,0 +1,50 @@
> >
+/******************************************************************************
> > + * hypercall.h
> > + *
> > + * Linux-specific hypervisor handling.
> > + *
> > + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Citrix, 2012
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
version 2
> > + * as published by the Free Software Foundation; or, when distributed
> > + * separately from the Linux kernel or incorporated into other
> > + * software packages, subject to the following license:
> > + *
> > + * Permission is hereby granted, free of charge, to any person
obtaining a copy
> > + * of this source file (the "Software"), to deal in the
Software without
> > + * restriction, including without limitation the rights to use, copy,
modify,
> > + * merge, publish, distribute, sublicense, and/or sell copies of the
Software,
> > + * and to permit persons to whom the Software is furnished to do so,
subject to
> > + * the following conditions:
> > + *
> > + * The above copyright notice and this permission notice shall be
included in
> > + * all copies or substantial portions of the Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
SHALL THE
> > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING
> > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS
> > + * IN THE SOFTWARE.
> > + */
> > +
> > +#ifndef _ASM_ARM_XEN_HYPERCALL_H
> > +#define _ASM_ARM_XEN_HYPERCALL_H
> > +
> > +#include <xen/interface/xen.h>
> > +
> > +long privcmd_call(unsigned call, unsigned long a1,
> > +		unsigned long a2, unsigned long a3,
> > +		unsigned long a4, unsigned long a5);
> > +int HYPERVISOR_xen_version(int cmd, void *arg);
> > +int HYPERVISOR_console_io(int cmd, int count, char *str);
> > +int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned
int count);
> > +int HYPERVISOR_sched_op(int cmd, void *arg);
> > +int HYPERVISOR_event_channel_op(int cmd, void *arg);
> > +unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> > +int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> > +int HYPERVISOR_physdev_op(int cmd, void *arg);
> > +
> > +#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> > diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> > index 0bad594..b9d6acc 100644
> > --- a/arch/arm/xen/Makefile
> > +++ b/arch/arm/xen/Makefile
> > @@ -1 +1 @@
> > -obj-y		:= enlighten.o
> > +obj-y		:= enlighten.o hypercall.o
> > diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
> > new file mode 100644
> > index 0000000..038cc5b
> > --- /dev/null
> > +++ b/arch/arm/xen/hypercall.S
> > @@ -0,0 +1,65 @@
> >
+/******************************************************************************
> > + * hypercall.S
> > + *
> > + * Xen hypercall wrappers
> > + *
> > + * The Xen hypercall calling convention is very similar to the ARM
> > + * procedure calling convention: the first paramter is passed in r0,
the
> > + * second in r1, the third in r2 and the third in r3. Considering
that
> 
> I think you meant ''and the fourth in r3''.
> 
> So where does the similarity end?  Just in that we use r12?
The standard ARM function calling convention is arguments 1-4 on r0-r3
and arguments 5+ on the stack. r12 is a scratch register which can be
clobbered by the *linker* on subroutine call (r12 is also called "ip"
the intra-procedure call scratch register).

The hypervisor doesn''t want to be accessing hypercall arguments off the
guest stack, for obvious reasons, so we use r4 for the fifth argument
(and if we even implemented 6 argument hypercalls we''d use r5, etc).
There is no equivalent to the hypercall number in the procedure calling
convention so we picked r12 because it is up and out of the way and is
otherwise a scratch register. Obviously that you must not make a
procedure call between setting the hypercall number in r12 and calling
the hvc instruction.
> 
> > + * Xen hypercalls have 5 arguments at most, the fifth paramter is
passed
> > + * in r4, differently from the procedure calling convention of using
the
> 
> > + * stack for that case.
> > + *
> > + * The hypercall number is passed in r12.
> > + *
> > + * The return value is in r0.
> > + *
> > + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> > + * hypercall tag.
> > + *
> > + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Citrix, 2012
> > + */
> > +
> > +#include <linux/linkage.h>
> > +#include <asm/assembler.h>
> > +#include <xen/interface/xen.h>
> > +
> > +
> > +/* HVC 0xEA1 */
> > +#ifdef CONFIG_THUMB2_KERNEL
> > +#define xen_hvc .word 0xf7e08ea1
> > +#else
> > +#define xen_hvc .word 0xe140ea71
> > +#endif
> > +
> > +/* We need to save and restore r4, because Xen clobbers it. */
> 
> Hmm, the comment says r4, but right below I see r12?
The ARM procedure calling convention allows a subroutine to clobber
r1..r3 (r0 is the return value) but not r4 which must be preserved. But
the hypervisor ABI clobbers all argument registers so the caller has to
specially preserve r4 in this context whenever there is a 5 argument
hypercall.

I presume that none of the hypercalls defined below have 5 arguments and
therefore we don''t need to preserve r4 except in the generic
privcmd_call function. 

To be honest I prefer the style which we use on x86 which is to define
hypercall{0,1,2,3,4,5} macros and to wrap those with the specific names
using inline functions.

I find the x86 way more self documenting, and being in C prevents errors
around the number of arguments. It also allows for better in-lining and
exposes to gcc the actual clobbers, which might allow it to avoid saving
r4 on the stack at all etc.
> Should this comment be by ''privcmd_call''?
When we add a 5 argument hypercall I suppose we''ll see the required
push/pop of r4 added to this macro too.
> > +#define HYPERCALL(hypercall)			\
> > +ENTRY(HYPERVISOR_##hypercall)			\
> > +	mov r12, #__HYPERVISOR_##hypercall;	\
> > +	xen_hvc;							\
> > +	mov pc, lr;							\
> > +ENDPROC(HYPERVISOR_##hypercall)
> > +
> > +                .text
> > +
> > +HYPERCALL(xen_version);
> > +HYPERCALL(console_io);
> > +HYPERCALL(grant_table_op);
> > +HYPERCALL(sched_op);
> > +HYPERCALL(event_channel_op);
> > +HYPERCALL(hvm_op);
> > +HYPERCALL(memory_op);
> > +HYPERCALL(physdev_op);
> > +
> > +ENTRY(privcmd_call)
> > +	stmdb	sp!, {r4}
> > +	mov r12, r0
> > +	mov r0, r1
> > +	mov r1, r2
> > +	mov r2, r3
> > +	ldr r3, [sp, #8]
> > +	ldr r4, [sp, #4]
> > +	xen_hvc
> > +	pop {r4}
Why not ldmdb for symmetry?
> > +	mov pc, lr
> > +ENDPROC(privcmd_call);
> > -- 
> > 1.7.2.5
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xen.org
> > http://lists.xen.org/xen-devel

Ian Campbell

2012-Jul-27 09:19 UTC

head link

Re: [PATCH 02/24] xen/arm: hypercalls

On Thu, 2012-07-26 at 20:19 +0100, Christopher Covington
wrote:> Hi Stefano,
> 
> On 07/26/2012 11:33 AM, Stefano Stabellini wrote:
> > Use r12 to pass the hypercall number to the hypervisor.
> > 
> > We need a register to pass the hypercall number because we might not
> > know it at compile time and HVC only takes an immediate argument.
> 
> You''re not going to JIT assemble the appropriate HVC instruction?
Darn.
;-)
> How many call numbers are there, though? 8?
The maximum currently defined hypercall number is 55, although there are
some small gaps so there''s actually more like 45 in total.
>  It seems like it''d be
> reasonable to take the approach that seems to be favored for MRC/MCR
> instructions, using a function containing switch statement that chooses
> between several inline assembly instructions based off an enum passed to
> the function. See for example arch_timer_reg_read in
> arch/arm/kernel/arch_timer.c.
I don''t think it is feasible with this number of hypercalls, even
accepting that in many cases the number will be a constant so gcc can
likely optimise almost all of it away.

Is there something wrong with the r12 based approach?

Ian.

Ian Campbell

2012-Jul-27 09:28 UTC

head link

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

On Thu, 2012-07-26 at 17:37 +0100, Konrad Rzeszutek Wilk
wrote:> On Thu, Jul 26, 2012 at 04:33:46PM +0100, Stefano Stabellini wrote:
> > sync_bitops functions are equivalent to the SMP implementation of the
> > original functions, independently from CONFIG_SMP being defined.
> 
> So why can''t the code be changed to use that? Is it that
> the _set_bit, _clear_bit, etc are not available with !CONFIG_SMP?
_set_bit etc are not SMP safe if !CONFIG_SMP. But under Xen you might be
communicating with a completely external entity who might be on another
CPU (e.g. two uniprocessor guests communicating via event channels and
grant tables). So we need a variant of the bit ops which are SMP safe
even on a UP kernel.

The users are common code and the sync_foo vs foo distinction matters on
some platforms (e.g. x86 where a UP kernel would omit the LOCK prefix
for the normal ones).
> 
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/include/asm/sync_bitops.h |   17 +++++++++++++++++
> >  1 files changed, 17 insertions(+), 0 deletions(-)
> >  create mode 100644 arch/arm/include/asm/sync_bitops.h
> > 
> > diff --git a/arch/arm/include/asm/sync_bitops.h
b/arch/arm/include/asm/sync_bitops.h
> > new file mode 100644
> > index 0000000..d975092903
> > --- /dev/null
> > +++ b/arch/arm/include/asm/sync_bitops.h
> > @@ -0,0 +1,17 @@
> > +#ifndef __ASM_SYNC_BITOPS_H__
> > +#define __ASM_SYNC_BITOPS_H__
> > +
> > +#include <asm/bitops.h>
> > +#include <asm/system.h>
> > +
> > +#define sync_set_bit(nr, p)		_set_bit(nr, p)
> > +#define sync_clear_bit(nr, p)		_clear_bit(nr, p)
> > +#define sync_change_bit(nr, p)		_change_bit(nr, p)
> > +#define sync_test_and_set_bit(nr, p)	_test_and_set_bit(nr, p)
> > +#define sync_test_and_clear_bit(nr, p)	_test_and_clear_bit(nr, p)
> > +#define sync_test_and_change_bit(nr, p)	_test_and_change_bit(nr, p)
> > +#define sync_test_bit(nr, addr)		test_bit(nr, addr)
> > +#define sync_cmpxchg			cmpxchg
> > +
> > +
> > +#endif
> > -- 
> > 1.7.2.5
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xen.org
> > http://lists.xen.org/xen-devel

Ian Campbell

2012-Jul-27 09:36 UTC

head link

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini
wrote:> Check for a "/xen" node in the device tree, if it is present set
> xen_domain_type to XEN_HVM_DOMAIN and continue initialization.
> 
> Map the real shared info page using XENMEM_add_to_physmap with
> XENMAPSPACE_shared_info.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c |   56
++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 56 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index d27c2a6..8c923af 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -5,6 +5,9 @@
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
>  
>  struct start_info _xen_start_info;
>  struct start_info *xen_start_info = &_xen_start_info;
> @@ -33,3 +36,56 @@ int xen_remap_domain_mfn_range(struct vm_area_struct
*vma,
>  	return -ENOSYS;
>  }
>  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> +
> +/*
> + * == Xen Device Tree format => + * - /xen node;
> + * - compatible "arm,xen";
> + * - one interrupt for Xen event notifications;
> + * - one memory region to map the grant_table.
> + */
> +static int __init xen_guest_init(void)
> +{
> +	int cpu;
> +	struct xen_add_to_physmap xatp;
> +	static struct shared_info *shared_info_page = 0;
> +	struct device_node *node;
> +
> +	node = of_find_compatible_node(NULL, NULL, "arm,xen");
> +	if (!node) {
> +		pr_info("No Xen support\n");
> +		return 0;
> +	}
This should either only print in the success case (to avoid spamming
everyone) or we need a little bit of infrastructure like on x86 so that
we print exactly one of:
	"Booting natively on bearmetal"
	"Booting paravirtualised on %s", hypervisor->name
> +	xen_domain_type = XEN_HVM_DOMAIN;
> +
> +	if (!shared_info_page)
> +		shared_info_page = (struct shared_info *)
> +			get_zeroed_page(GFP_KERNEL);
> +	if (!shared_info_page) {
> +		pr_err("not enough memory");
> +		return -ENOMEM;
> +	}
> +	xatp.domid = DOMID_SELF;
> +	xatp.idx = 0;
> +	xatp.space = XENMAPSPACE_shared_info;
> +	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> +		BUG();
> +
> +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> +
> +	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
> +	 * page, we use it in the event channel upcall and in some pvclock
> +	 * related functions. We don''t need the vcpu_info placement
> +	 * optimizations because we don''t use any pv_mmu or pv_irq op on
> +	 * HVM.
> +	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
> +	 * online but xen_hvm_init_shared_info is run at resume time too and
> +	 * in that case multiple vcpus might be online. */
> +	for_each_online_cpu(cpu) {
> +		per_cpu(xen_vcpu, cpu) > +		
&HYPERVISOR_shared_info->vcpu_info[cpu];
On ARM the shared info contains exactly 1 CPU (the boot CPU). The guest
is required to use VCPUOP_register_vcpu_info to place vcpu info for
secondary CPUs as they are brought up.

Ian.

Ian Campbell

2012-Jul-27 09:42 UTC

head link

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini
wrote:> We used to rely on a core_initcall to initialize Xen on ARM, however
> core_initcalls are actually called after early consoles are initialized.
> That means that hvc_xen.c is going to be initialized before Xen.
> 
> Given the lack of a better alternative, just call a new Xen
> initialization function (xen_guest_init) from xen_cons_init.
Can''t we just arrange for this to be called super early on from
setup_arch? That''s got to be better than calling it from some random
function which happens to get called early enough.

I presume that KVM is going to want some similarly early init hooks etc
and therefore ARM could benefit from the same sort of infrastructure as
is in arch/x86/include/asm/hypervisor.h?

> 
> xen_guest_init has to be arch independent, so write both an ARM and an
> x86 implementation. The x86 implementation is currently empty because we
> can be sure that xen_hvm_guest_init is called early enough.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c  |    7 ++++++-
>  arch/x86/xen/enlighten.c  |    8 ++++++++
>  drivers/tty/hvc/hvc_xen.c |    7 ++++++-
>  include/xen/xen.h         |    2 ++
>  4 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 8c923af..dc68074 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -44,7 +44,7 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
>   * - one interrupt for Xen event notifications;
>   * - one memory region to map the grant_table.
>   */
> -static int __init xen_guest_init(void)
> +int __init xen_guest_init(void)
>  {
>  	int cpu;
>  	struct xen_add_to_physmap xatp;
> @@ -58,6 +58,10 @@ static int __init xen_guest_init(void)
>  	}
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
> +	/* already setup */
> +	if (shared_info_page != 0 && HYPERVISOR_shared_info ==
shared_info_page)
> +		return 0;
> +
>  	if (!shared_info_page)
>  		shared_info_page = (struct shared_info *)
>  			get_zeroed_page(GFP_KERNEL);
> @@ -88,4 +92,5 @@ static int __init xen_guest_init(void)
>  	}
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(xen_guest_init);
>  core_initcall(xen_guest_init);
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index ff962d4..6131d43 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1567,4 +1567,12 @@ const struct hypervisor_x86 x86_hyper_xen_hvm
__refconst = {
>  	.init_platform		= xen_hvm_guest_init,
>  };
>  EXPORT_SYMBOL(x86_hyper_xen_hvm);
> +
> +int __init xen_guest_init(void)
> +{
> +	/* do nothing: rely on x86_hyper_xen_hvm for the initialization */
> +	return 0;
> +	
> +}
> +EXPORT_SYMBOL_GPL(xen_guest_init);
>  #endif
> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> index dc07f56..3c04fb8 100644
> --- a/drivers/tty/hvc/hvc_xen.c
> +++ b/drivers/tty/hvc/hvc_xen.c
> @@ -577,6 +577,12 @@ static void __exit xen_hvc_fini(void)
>  static int xen_cons_init(void)
>  {
>  	const struct hv_ops *ops;
> +	int r;
> +
> +	/* retrieve xen infos  */
> +	r = xen_guest_init();
> +	if (r < 0)
> +		return r;
>  
>  	if (!xen_domain())
>  		return 0;
> @@ -584,7 +590,6 @@ static int xen_cons_init(void)
>  	if (xen_initial_domain())
>  		ops = &dom0_hvc_ops;
>  	else {
> -		int r;
>  		ops = &domU_hvc_ops;
>  
>  		if (xen_hvm_domain())
> diff --git a/include/xen/xen.h b/include/xen/xen.h
> index 2c0d3a5..792a4d2 100644
> --- a/include/xen/xen.h
> +++ b/include/xen/xen.h
> @@ -9,8 +9,10 @@ enum xen_domain_type {
>  
>  #ifdef CONFIG_XEN
>  extern enum xen_domain_type xen_domain_type;
> +int xen_guest_init(void);
>  #else
>  #define xen_domain_type		XEN_NATIVE
> +static inline int xen_guest_init(void) { return 0; }
>  #endif
>  
>  #define xen_domain()		(xen_domain_type != XEN_NATIVE)

Ian Campbell

2012-Jul-27 09:44 UTC

head link

Re: [PATCH 13/24] xen/arm: get privilege status

On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini
wrote:> Use Xen features to figure out if we are privileged.
> 
> XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c         |    7 +++++++
>  include/xen/interface/features.h |    3 +++
>  2 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index dc68074..2e013cf 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -2,6 +2,7 @@
>  #include <xen/interface/xen.h>
>  #include <xen/interface/memory.h>
>  #include <xen/platform_pci.h>
> +#include <xen/features.h>
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include <linux/module.h>
> @@ -58,6 +59,12 @@ int __init xen_guest_init(void)
>  	}
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
> +	xen_setup_features();
> +	if (xen_feature(XENFEAT_dom0))
> +		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
> +	else
> +		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
What happens here on platforms prior to hypervisor changeset 23735?
> +
>  	/* already setup */
>  	if (shared_info_page != 0 && HYPERVISOR_shared_info ==
shared_info_page)
>  		return 0;
> diff --git a/include/xen/interface/features.h
b/include/xen/interface/features.h
> index b6ca39a..131a6cc 100644
> --- a/include/xen/interface/features.h
> +++ b/include/xen/interface/features.h
> @@ -50,6 +50,9 @@
>  /* x86: pirq can be used by HVM guests */
>  #define XENFEAT_hvm_pirqs           10
>  
> +/* operation as Dom0 is supported */
> +#define XENFEAT_dom0                      11
> +
>  #define XENFEAT_NR_SUBMAPS 1
>  
>  #endif /* __XEN_PUBLIC_FEATURES_H__ */

Ian Campbell

2012-Jul-27 09:48 UTC

head link

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

On Thu, 2012-07-26 at 16:34 +0100, Stefano Stabellini
wrote:> 
> +#define XEN_IO_PROTO_ABI_ARM        "arm-abi" 
I wonder if we ought to call this arm-aarch32-abi or something?

I wonder if we can also take the opportunity to fix the ABI cockup for
disks on ARM and make the structs the same for both 32 and 64 bit?

Ian.

Stefano Stabellini

2012-Jul-27 11:56 UTC

head link

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

On Thu, 26 Jul 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:43PM +0100, Stefano Stabellini wrote:
> > - Basic hypervisor.h and interface.h definitions.
> > - Skelethon enlighten.c, set xen_start_info to an empty struct.
> 
> Skeleton
> 
> > - Do not limit xen_initial_domain to PV guests.
> 
> Better wording: Make xen_initial_domain dependent on the
SIF_PRIVILIGED_BIT.
> 
> Which reminds me - what about PV guests that do PCI passthrough.
Aren''t
> they "more" priviligied than normal PV guests? Or not really?
Not really, from the Xen POV.

> > The new code only compiles when CONFIG_XEN is set, that is going to be
> > added to arch/arm/Kconfig in a later patch.
> 
> s/later patch/<name of patch>/
> 
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/Makefile                     |    1 +
> >  arch/arm/include/asm/hypervisor.h     |    6 +++
> >  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
> >  arch/arm/include/asm/xen/interface.h  |   64
+++++++++++++++++++++++++++++++++
> >  arch/arm/xen/Makefile                 |    1 +
> >  arch/arm/xen/enlighten.c              |   35 ++++++++++++++++++
> >  include/xen/xen.h                     |    2 +-
> >  7 files changed, 127 insertions(+), 1 deletions(-)
> >  create mode 100644 arch/arm/include/asm/hypervisor.h
> >  create mode 100644 arch/arm/include/asm/xen/hypervisor.h
> >  create mode 100644 arch/arm/include/asm/xen/interface.h
> >  create mode 100644 arch/arm/xen/Makefile
> >  create mode 100644 arch/arm/xen/enlighten.c
> > 
> > diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> > index 0298b00..70aaa82 100644
> > --- a/arch/arm/Makefile
> > +++ b/arch/arm/Makefile
> > @@ -246,6 +246,7 @@ endif
> >  core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
> >  core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
> >  core-$(CONFIG_VFP)		+= arch/arm/vfp/
> > +core-$(CONFIG_XEN)		+= arch/arm/xen/
> >  
> >  # If we have a machine-specific directory, then include it in the
build.
> >  core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
> > diff --git a/arch/arm/include/asm/hypervisor.h
b/arch/arm/include/asm/hypervisor.h
> > new file mode 100644
> > index 0000000..b90d9e5
> > --- /dev/null
> > +++ b/arch/arm/include/asm/hypervisor.h
> > @@ -0,0 +1,6 @@
> > +#ifndef _ASM_ARM_HYPERVISOR_H
> > +#define _ASM_ARM_HYPERVISOR_H
> > +
> > +#include <asm/xen/hypervisor.h>
> > +
> > +#endif
> > diff --git a/arch/arm/include/asm/xen/hypervisor.h
b/arch/arm/include/asm/xen/hypervisor.h
> > new file mode 100644
> > index 0000000..d7ab99a
> > --- /dev/null
> > +++ b/arch/arm/include/asm/xen/hypervisor.h
> > @@ -0,0 +1,19 @@
> > +#ifndef _ASM_ARM_XEN_HYPERVISOR_H
> > +#define _ASM_ARM_XEN_HYPERVISOR_H
> > +
> > +extern struct shared_info *HYPERVISOR_shared_info;
> > +extern struct start_info *xen_start_info;
> > +
> > +/* Lazy mode for batching updates / context switch */
> > +enum paravirt_lazy_mode {
> > +	PARAVIRT_LAZY_NONE,
> > +	PARAVIRT_LAZY_MMU,
> > +	PARAVIRT_LAZY_CPU,
> > +};
> > +
> > +static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
> > +{
> > +	return PARAVIRT_LAZY_NONE;
> > +}
> > +
> > +#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
> > diff --git a/arch/arm/include/asm/xen/interface.h
b/arch/arm/include/asm/xen/interface.h
> > new file mode 100644
> > index 0000000..6c3ab59
> > --- /dev/null
> > +++ b/arch/arm/include/asm/xen/interface.h
> > @@ -0,0 +1,64 @@
> >
+/******************************************************************************
> > + * Guest OS interface to ARM Xen.
> > + *
> > + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Citrix, 2011
> 
> 2012
> 
> > + */
> > +
> > +#ifndef _ASM_ARM_XEN_INTERFACE_H
> > +#define _ASM_ARM_XEN_INTERFACE_H
> > +
> > +#include <linux/types.h>
> > +
> > +#define __DEFINE_GUEST_HANDLE(name, type) \
> > +	typedef type * __guest_handle_ ## name
> > +
> > +#define DEFINE_GUEST_HANDLE_STRUCT(name) \
> > +	__DEFINE_GUEST_HANDLE(name, struct name)
> > +#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
> > +#define GUEST_HANDLE(name)        __guest_handle_ ## name
> > +
> > +#define set_xen_guest_handle(hnd, val)			\
> > +	do {						\
> > +		if (sizeof(hnd) == 8)			\
> > +			*(uint64_t *)&(hnd) = 0;	\
> > +		(hnd) = val;				\
> > +	} while (0)
> > +
> > +#ifndef __ASSEMBLY__
> > +/* Guest handles for primitive C types. */
> > +__DEFINE_GUEST_HANDLE(uchar, unsigned char);
> > +__DEFINE_GUEST_HANDLE(uint,  unsigned int);
> > +__DEFINE_GUEST_HANDLE(ulong, unsigned long);
> > +DEFINE_GUEST_HANDLE(char);
> > +DEFINE_GUEST_HANDLE(int);
> > +DEFINE_GUEST_HANDLE(long);
> > +DEFINE_GUEST_HANDLE(void);
> > +DEFINE_GUEST_HANDLE(uint64_t);
> > +DEFINE_GUEST_HANDLE(uint32_t);
> > +
> > +/* Maximum number of virtual CPUs in multi-processor guests. */
> > +#define MAX_VIRT_CPUS 1
> > +
> > +struct arch_vcpu_info { };
> > +struct arch_shared_info { };
> > +
> > +/* XXX: Move pvclock definitions some place arch independent */
> > +struct pvclock_vcpu_time_info {
> > +	u32   version;
> > +	u32   pad0;
> > +	u64   tsc_timestamp;
> > +	u64   system_time;
> > +	u32   tsc_to_system_mul;
> > +	s8    tsc_shift;
> > +	u8    flags;
> > +	u8    pad[2];
> > +} __attribute__((__packed__)); /* 32 bytes */
> > +
> > +struct pvclock_wall_clock {
> > +	u32   version;
> > +	u32   sec;
> > +	u32   nsec;
> > +} __attribute__((__packed__));
> 
> That is weird. It is 4+4+4 = 12 bytes? Don''t you want it to be 16
bytes?
I agree that 16 bytes would be a better choice, but it needs to match
the struct in Xen that is defined as follow:

    uint32_t wc_version;      /* Version counter: see vcpu_time_info_t. */
    uint32_t wc_sec;          /* Secs  00:00:00 UTC, Jan 1, 1970.  */
    uint32_t wc_nsec;         /* Nsecs 00:00:00 UTC, Jan 1, 1970.  */

in xen/include/public/xen.h.

> > +#endif
> > +
> > +#endif /* _ASM_ARM_XEN_INTERFACE_H */
> > diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> > new file mode 100644
> > index 0000000..0bad594
> > --- /dev/null
> > +++ b/arch/arm/xen/Makefile
> > @@ -0,0 +1 @@
> > +obj-y		:= enlighten.o
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > new file mode 100644
> > index 0000000..d27c2a6
> > --- /dev/null
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -0,0 +1,35 @@
> > +#include <xen/xen.h>
> > +#include <xen/interface/xen.h>
> > +#include <xen/interface/memory.h>
> > +#include <xen/platform_pci.h>
> > +#include <asm/xen/hypervisor.h>
> > +#include <asm/xen/hypercall.h>
> > +#include <linux/module.h>
> > +
> > +struct start_info _xen_start_info;
> > +struct start_info *xen_start_info = &_xen_start_info;
> > +EXPORT_SYMBOL_GPL(xen_start_info);
> > +
> > +enum xen_domain_type xen_domain_type = XEN_NATIVE;
> > +EXPORT_SYMBOL_GPL(xen_domain_type);
> > +
> > +struct shared_info xen_dummy_shared_info;
> > +struct shared_info *HYPERVISOR_shared_info = (void
*)&xen_dummy_shared_info;
> > +
> > +DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
> > +
> > +/* XXX: to be removed */
> 
> In this patch series later on? Or just when you try to collapse the x86 and
arm variant
> together?
The latter.
It is not harmful but we don''t need xen_have_vector_callback on ARM, so
it
would be nice if we didn''t have to define it here.

> > +__read_mostly int xen_have_vector_callback;
> > +EXPORT_SYMBOL_GPL(xen_have_vector_callback);
> > +
> > +int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
> > +EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
> > +
> > +int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> > +			       unsigned long addr,
> > +			       unsigned long mfn, int nr,
> > +			       pgprot_t prot, unsigned domid)
> > +{
> > +	return -ENOSYS;
> > +}
> > +EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> > diff --git a/include/xen/xen.h b/include/xen/xen.h
> > index a164024..2c0d3a5 100644
> > --- a/include/xen/xen.h
> > +++ b/include/xen/xen.h
> > @@ -23,7 +23,7 @@ extern enum xen_domain_type xen_domain_type;
> >  #include <xen/interface/xen.h>
> >  #include <asm/xen/hypervisor.h>
> >  
> > -#define xen_initial_domain()	(xen_pv_domain() && \
> > +#define xen_initial_domain()	(xen_domain() && \
> >  				 xen_start_info->flags & SIF_INITDOMAIN)
> >  #else  /* !CONFIG_XEN_DOM0 */
> >  #define xen_initial_domain()	(0)
> > -- 
> > 1.7.2.5
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xen.org
> > http://lists.xen.org/xen-devel
>

Christopher Covington

2012-Jul-27 12:56 UTC

head link

Re: [PATCH 02/24] xen/arm: hypercalls

On 07/27/2012 05:19 AM, Ian Campbell wrote:> On Thu, 2012-07-26 at 20:19 +0100, Christopher Covington wrote:
>> Hi Stefano,
>>
>> On 07/26/2012 11:33 AM, Stefano Stabellini wrote:
>>> Use r12 to pass the hypercall number to the hypervisor.
>>>
>>> We need a register to pass the hypercall number because we might
not
>>> know it at compile time and HVC only takes an immediate argument.
>>
>> You''re not going to JIT assemble the appropriate HVC
instruction? Darn.
> 
> ;-)
> 
>> How many call numbers are there, though? 8?
> 
> The maximum currently defined hypercall number is 55, although there are
> some small gaps so there''s actually more like 45 in total.
> 
>>  It seems like it''d be
>> reasonable to take the approach that seems to be favored for MRC/MCR
>> instructions, using a function containing switch statement that chooses
>> between several inline assembly instructions based off an enum passed
to
>> the function. See for example arch_timer_reg_read in
>> arch/arm/kernel/arch_timer.c.
> 
> I don''t think it is feasible with this number of hypercalls, even
> accepting that in many cases the number will be a constant so gcc can
> likely optimise almost all of it away.
> 
> Is there something wrong with the r12 based approach?
Only that you''re defining a custom interface for something that there
is
a potentially more standard interface for. I just wanted to double check
that all the ways of using the potentially more standard interface had
been explored and found to be unreasonable.

Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

Stefano Stabellini

2012-Jul-27 13:02 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, 27 Jul 2012, Ian Campbell wrote:> On Thu, 2012-07-26 at 17:33 +0100, Konrad Rzeszutek Wilk wrote:
> > On Thu, Jul 26, 2012 at 04:33:44PM +0100, Stefano Stabellini wrote:
> > > Use r12 to pass the hypercall number to the hypervisor.
> > > 
> > > We need a register to pass the hypercall number because we might
not
> > > know it at compile time and HVC only takes an immediate argument.
> > > 
> > > Among the available registers r12 seems to be the best choice
because it
> > > is defined as "intra-procedure call scratch register".
> > > 
> > > Use the ISS to pass an hypervisor specific tag.
> > > 
> > > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > > ---
> > >  arch/arm/include/asm/xen/hypercall.h |   50
++++++++++++++++++++++++++
> > >  arch/arm/xen/Makefile                |    2 +-
> > >  arch/arm/xen/hypercall.S             |   65
++++++++++++++++++++++++++++++++++
> > >  3 files changed, 116 insertions(+), 1 deletions(-)
> > >  create mode 100644 arch/arm/include/asm/xen/hypercall.h
> > >  create mode 100644 arch/arm/xen/hypercall.S
> > > 
> > > diff --git a/arch/arm/include/asm/xen/hypercall.h
b/arch/arm/include/asm/xen/hypercall.h
> > > new file mode 100644
> > > index 0000000..4ac0624
> > > --- /dev/null
> > > +++ b/arch/arm/include/asm/xen/hypercall.h
> > > @@ -0,0 +1,50 @@
> > >
+/******************************************************************************
> > > + * hypercall.h
> > > + *
> > > + * Linux-specific hypervisor handling.
> > > + *
> > > + * Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>, Citrix, 2012
> > > + *
> > > + * This program is free software; you can redistribute it and/or
> > > + * modify it under the terms of the GNU General Public License
version 2
> > > + * as published by the Free Software Foundation; or, when
distributed
> > > + * separately from the Linux kernel or incorporated into other
> > > + * software packages, subject to the following license:
> > > + *
> > > + * Permission is hereby granted, free of charge, to any person
obtaining a copy
> > > + * of this source file (the "Software"), to deal in
the Software without
> > > + * restriction, including without limitation the rights to use,
copy, modify,
> > > + * merge, publish, distribute, sublicense, and/or sell copies of
the Software,
> > > + * and to permit persons to whom the Software is furnished to do
so, subject to
> > > + * the following conditions:
> > > + *
> > > + * The above copyright notice and this permission notice shall
be included in
> > > + * all copies or substantial portions of the Software.
> > > + *
> > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY
OF ANY KIND, EXPRESS OR
> > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
> > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
EVENT SHALL THE
> > > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
OR OTHER
> > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
OTHERWISE, ARISING
> > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS
> > > + * IN THE SOFTWARE.
> > > + */
> > > +
> > > +#ifndef _ASM_ARM_XEN_HYPERCALL_H
> > > +#define _ASM_ARM_XEN_HYPERCALL_H
> > > +
> > > +#include <xen/interface/xen.h>
> > > +
> > > +long privcmd_call(unsigned call, unsigned long a1,
> > > +		unsigned long a2, unsigned long a3,
> > > +		unsigned long a4, unsigned long a5);
> > > +int HYPERVISOR_xen_version(int cmd, void *arg);
> > > +int HYPERVISOR_console_io(int cmd, int count, char *str);
> > > +int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop,
unsigned int count);
> > > +int HYPERVISOR_sched_op(int cmd, void *arg);
> > > +int HYPERVISOR_event_channel_op(int cmd, void *arg);
> > > +unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> > > +int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> > > +int HYPERVISOR_physdev_op(int cmd, void *arg);
> > > +
> > > +#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> > > diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> > > index 0bad594..b9d6acc 100644
> > > --- a/arch/arm/xen/Makefile
> > > +++ b/arch/arm/xen/Makefile
> > > @@ -1 +1 @@
> > > -obj-y		:= enlighten.o
> > > +obj-y		:= enlighten.o hypercall.o
> > > diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
> > > new file mode 100644
> > > index 0000000..038cc5b
> > > --- /dev/null
> > > +++ b/arch/arm/xen/hypercall.S
> > > @@ -0,0 +1,65 @@
> > >
+/******************************************************************************
> > > + * hypercall.S
> > > + *
> > > + * Xen hypercall wrappers
> > > + *
> > > + * The Xen hypercall calling convention is very similar to the
ARM
> > > + * procedure calling convention: the first paramter is passed in
r0, the
> > > + * second in r1, the third in r2 and the third in r3.
Considering that
> > 
> > I think you meant ''and the fourth in r3''.
> > 
> > So where does the similarity end?  Just in that we use r12?
> 
> The standard ARM function calling convention is arguments 1-4 on r0-r3
> and arguments 5+ on the stack. r12 is a scratch register which can be
> clobbered by the *linker* on subroutine call (r12 is also called
"ip"
> the intra-procedure call scratch register).
> 
> The hypervisor doesn''t want to be accessing hypercall arguments
off the
> guest stack, for obvious reasons, so we use r4 for the fifth argument
> (and if we even implemented 6 argument hypercalls we''d use r5,
etc).
> There is no equivalent to the hypercall number in the procedure calling
> convention so we picked r12 because it is up and out of the way and is
> otherwise a scratch register. Obviously that you must not make a
> procedure call between setting the hypercall number in r12 and calling
> the hvc instruction.
> 
> > 
> > > + * Xen hypercalls have 5 arguments at most, the fifth paramter
is passed
> > > + * in r4, differently from the procedure calling convention of
using the
> > 
> > > + * stack for that case.
> > > + *
> > > + * The hypercall number is passed in r12.
> > > + *
> > > + * The return value is in r0.
> > > + *
> > > + * The hvc ISS is required to be 0xEA1, that is the Xen specific
ARM
> > > + * hypercall tag.
> > > + *
> > > + * Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>, Citrix, 2012
> > > + */
> > > +
> > > +#include <linux/linkage.h>
> > > +#include <asm/assembler.h>
> > > +#include <xen/interface/xen.h>
> > > +
> > > +
> > > +/* HVC 0xEA1 */
> > > +#ifdef CONFIG_THUMB2_KERNEL
> > > +#define xen_hvc .word 0xf7e08ea1
> > > +#else
> > > +#define xen_hvc .word 0xe140ea71
> > > +#endif
> > > +
> > > +/* We need to save and restore r4, because Xen clobbers it. */
> > 
> > Hmm, the comment says r4, but right below I see r12?
> 
> The ARM procedure calling convention allows a subroutine to clobber
> r1..r3 (r0 is the return value) but not r4 which must be preserved. But
> the hypervisor ABI clobbers all argument registers so the caller has to
> specially preserve r4 in this context whenever there is a 5 argument
> hypercall.
> 
> I presume that none of the hypercalls defined below have 5 arguments and
> therefore we don''t need to preserve r4 except in the generic
> privcmd_call function. 
> 
> To be honest I prefer the style which we use on x86 which is to define
> hypercall{0,1,2,3,4,5} macros and to wrap those with the specific names
> using inline functions.
> 
> I find the x86 way more self documenting, and being in C prevents errors
> around the number of arguments. It also allows for better in-lining and
> exposes to gcc the actual clobbers, which might allow it to avoid saving
> r4 on the stack at all etc.
Considering that we cannot do the same thing that we do on x86 (see this
thread http://marc.info/?l=linux-kernel&m=133052035426427&w=2), I
decided to go for the assembly implementation because it is much shorter
and easier to understand (for me at least, being just 3 lines of code in
the generic case and just one macro) and this way we can exploit the
code generated by gcc to put the arguments in the right registers.

Also I like the fact that it is the same strategy used by libc to issue
syscalls.

As you can see it results in 3 lines of code for all the hypercalls
except the ones that might take more than 4 arguments, that right now is
just privcmd.


> > Should this comment be by ''privcmd_call''?
> 
> When we add a 5 argument hypercall I suppose we''ll see the
required
> push/pop of r4 added to this macro too.
For performance and simplicity I would add a second macro that push/pop
r4, only required for hypercalls with more than 4 arguments.

> > > +#define HYPERCALL(hypercall)			\
> > > +ENTRY(HYPERVISOR_##hypercall)			\
> > > +	mov r12, #__HYPERVISOR_##hypercall;	\
> > > +	xen_hvc;							\
> > > +	mov pc, lr;							\
> > > +ENDPROC(HYPERVISOR_##hypercall)
> > > +
> > > +                .text
> > > +
> > > +HYPERCALL(xen_version);
> > > +HYPERCALL(console_io);
> > > +HYPERCALL(grant_table_op);
> > > +HYPERCALL(sched_op);
> > > +HYPERCALL(event_channel_op);
> > > +HYPERCALL(hvm_op);
> > > +HYPERCALL(memory_op);
> > > +HYPERCALL(physdev_op);
> > > +
> > > +ENTRY(privcmd_call)
> > > +	stmdb	sp!, {r4}
> > > +	mov r12, r0
> > > +	mov r0, r1
> > > +	mov r1, r2
> > > +	mov r2, r3
> > > +	ldr r3, [sp, #8]
> > > +	ldr r4, [sp, #4]
> > > +	xen_hvc
> > > +	pop {r4}
> 
> Why not ldmdb for symmetry?
Yep, I can do that.

Ian Campbell

2012-Jul-27 13:18 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, 2012-07-27 at 14:02 +0100, Stefano Stabellini
wrote:> On Fri, 27 Jul 2012, Ian Campbell wrote:
> > On Thu, 2012-07-26 at 17:33 +0100, Konrad Rzeszutek Wilk wrote:
> > > On Thu, Jul 26, 2012 at 04:33:44PM +0100, Stefano Stabellini
wrote:
> > > > Use r12 to pass the hypercall number to the hypervisor.
> > > > 
> > > > We need a register to pass the hypercall number because we
might not
> > > > know it at compile time and HVC only takes an immediate
argument.
> > > > 
> > > > Among the available registers r12 seems to be the best
choice because it
> > > > is defined as "intra-procedure call scratch
register".
> > > > 
> > > > Use the ISS to pass an hypervisor specific tag.
> > > > 
> > > > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > > > ---
> > > >  arch/arm/include/asm/xen/hypercall.h |   50
++++++++++++++++++++++++++
> > > >  arch/arm/xen/Makefile                |    2 +-
> > > >  arch/arm/xen/hypercall.S             |   65
++++++++++++++++++++++++++++++++++
> > > >  3 files changed, 116 insertions(+), 1 deletions(-)
> > > >  create mode 100644 arch/arm/include/asm/xen/hypercall.h
> > > >  create mode 100644 arch/arm/xen/hypercall.S
> > > > 
> > > > diff --git a/arch/arm/include/asm/xen/hypercall.h
b/arch/arm/include/asm/xen/hypercall.h
> > > > new file mode 100644
> > > > index 0000000..4ac0624
> > > > --- /dev/null
> > > > +++ b/arch/arm/include/asm/xen/hypercall.h
> > > > @@ -0,0 +1,50 @@
> > > >
+/******************************************************************************
> > > > + * hypercall.h
> > > > + *
> > > > + * Linux-specific hypervisor handling.
> > > > + *
> > > > + * Stefano Stabellini
<stefano.stabellini@eu.citrix.com>, Citrix, 2012
> > > > + *
> > > > + * This program is free software; you can redistribute it
and/or
> > > > + * modify it under the terms of the GNU General Public
License version 2
> > > > + * as published by the Free Software Foundation; or, when
distributed
> > > > + * separately from the Linux kernel or incorporated into
other
> > > > + * software packages, subject to the following license:
> > > > + *
> > > > + * Permission is hereby granted, free of charge, to any
person obtaining a copy
> > > > + * of this source file (the "Software"), to deal
in the Software without
> > > > + * restriction, including without limitation the rights to
use, copy, modify,
> > > > + * merge, publish, distribute, sublicense, and/or sell
copies of the Software,
> > > > + * and to permit persons to whom the Software is furnished
to do so, subject to
> > > > + * the following conditions:
> > > > + *
> > > > + * The above copyright notice and this permission notice
shall be included in
> > > > + * all copies or substantial portions of the Software.
> > > > + *
> > > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT
WARRANTY OF ANY KIND, EXPRESS OR
> > > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
> > > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
NO EVENT SHALL THE
> > > > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER
> > > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
OTHERWISE, ARISING
> > > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
USE OR OTHER DEALINGS
> > > > + * IN THE SOFTWARE.
> > > > + */
> > > > +
> > > > +#ifndef _ASM_ARM_XEN_HYPERCALL_H
> > > > +#define _ASM_ARM_XEN_HYPERCALL_H
> > > > +
> > > > +#include <xen/interface/xen.h>
> > > > +
> > > > +long privcmd_call(unsigned call, unsigned long a1,
> > > > +		unsigned long a2, unsigned long a3,
> > > > +		unsigned long a4, unsigned long a5);
> > > > +int HYPERVISOR_xen_version(int cmd, void *arg);
> > > > +int HYPERVISOR_console_io(int cmd, int count, char *str);
> > > > +int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop,
unsigned int count);
> > > > +int HYPERVISOR_sched_op(int cmd, void *arg);
> > > > +int HYPERVISOR_event_channel_op(int cmd, void *arg);
> > > > +unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> > > > +int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> > > > +int HYPERVISOR_physdev_op(int cmd, void *arg);
> > > > +
> > > > +#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> > > > diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> > > > index 0bad594..b9d6acc 100644
> > > > --- a/arch/arm/xen/Makefile
> > > > +++ b/arch/arm/xen/Makefile
> > > > @@ -1 +1 @@
> > > > -obj-y		:= enlighten.o
> > > > +obj-y		:= enlighten.o hypercall.o
> > > > diff --git a/arch/arm/xen/hypercall.S
b/arch/arm/xen/hypercall.S
> > > > new file mode 100644
> > > > index 0000000..038cc5b
> > > > --- /dev/null
> > > > +++ b/arch/arm/xen/hypercall.S
> > > > @@ -0,0 +1,65 @@
> > > >
+/******************************************************************************
> > > > + * hypercall.S
> > > > + *
> > > > + * Xen hypercall wrappers
> > > > + *
> > > > + * The Xen hypercall calling convention is very similar to
the ARM
> > > > + * procedure calling convention: the first paramter is
passed in r0, the
> > > > + * second in r1, the third in r2 and the third in r3.
Considering that
> > > 
> > > I think you meant ''and the fourth in r3''.
> > > 
> > > So where does the similarity end?  Just in that we use r12?
> > 
> > The standard ARM function calling convention is arguments 1-4 on r0-r3
> > and arguments 5+ on the stack. r12 is a scratch register which can be
> > clobbered by the *linker* on subroutine call (r12 is also called
"ip"
> > the intra-procedure call scratch register).
> > 
> > The hypervisor doesn''t want to be accessing hypercall
arguments off the
> > guest stack, for obvious reasons, so we use r4 for the fifth argument
> > (and if we even implemented 6 argument hypercalls we''d use
r5, etc).
> > There is no equivalent to the hypercall number in the procedure
calling
> > convention so we picked r12 because it is up and out of the way and is
> > otherwise a scratch register. Obviously that you must not make a
> > procedure call between setting the hypercall number in r12 and calling
> > the hvc instruction.
> > 
> > > 
> > > > + * Xen hypercalls have 5 arguments at most, the fifth
paramter is passed
> > > > + * in r4, differently from the procedure calling convention
of using the
> > > 
> > > > + * stack for that case.
> > > > + *
> > > > + * The hypercall number is passed in r12.
> > > > + *
> > > > + * The return value is in r0.
> > > > + *
> > > > + * The hvc ISS is required to be 0xEA1, that is the Xen
specific ARM
> > > > + * hypercall tag.
> > > > + *
> > > > + * Stefano Stabellini
<stefano.stabellini@eu.citrix.com>, Citrix, 2012
> > > > + */
> > > > +
> > > > +#include <linux/linkage.h>
> > > > +#include <asm/assembler.h>
> > > > +#include <xen/interface/xen.h>
> > > > +
> > > > +
> > > > +/* HVC 0xEA1 */
> > > > +#ifdef CONFIG_THUMB2_KERNEL
> > > > +#define xen_hvc .word 0xf7e08ea1
> > > > +#else
> > > > +#define xen_hvc .word 0xe140ea71
> > > > +#endif
> > > > +
> > > > +/* We need to save and restore r4, because Xen clobbers it.
*/
> > > 
> > > Hmm, the comment says r4, but right below I see r12?
> > 
> > The ARM procedure calling convention allows a subroutine to clobber
> > r1..r3 (r0 is the return value) but not r4 which must be preserved.
But
> > the hypervisor ABI clobbers all argument registers so the caller has
to
> > specially preserve r4 in this context whenever there is a 5 argument
> > hypercall.
> > 
> > I presume that none of the hypercalls defined below have 5 arguments
and
> > therefore we don''t need to preserve r4 except in the generic
> > privcmd_call function. 
> > 
> > To be honest I prefer the style which we use on x86 which is to define
> > hypercall{0,1,2,3,4,5} macros and to wrap those with the specific
names
> > using inline functions.
> > 
> > I find the x86 way more self documenting, and being in C prevents
errors
> > around the number of arguments. It also allows for better in-lining
and
> > exposes to gcc the actual clobbers, which might allow it to avoid
saving
> > r4 on the stack at all etc.
> 
> Considering that we cannot do the same thing that we do on x86 (see this
> thread http://marc.info/?l=linux-kernel&m=133052035426427&w=2),
I''d forgotten all about this arm-gcc braindamage.
>  I
> decided to go for the assembly implementation because it is much shorter
> and easier to understand (for me at least, being just 3 lines of code in
> the generic case and just one macro) and this way we can exploit the
> code generated by gcc to put the arguments in the right registers.
> 
> Also I like the fact that it is the same strategy used by libc to issue
> syscalls.
Fair enough.
> As you can see it results in 3 lines of code for all the hypercalls
> except the ones that might take more than 4 arguments, that right now is
> just privcmd.
> 
> 
> 
> > > Should this comment be by ''privcmd_call''?
> > 
> > When we add a 5 argument hypercall I suppose we''ll see the
required
> > push/pop of r4 added to this macro too.
> 
> For performance and simplicity I would add a second macro that push/pop
> r4, only required for hypercalls with more than 4 arguments.
For clarity / documentation purposes it might actually be worthwhile to
define all of HYPERCALL{0,1,2,3,4} even if the {0,1,2,3} cases are all
just:
        #define HYPERCALL0(x) HYPERCALL_SIMPLE(x)
> > > > +#define HYPERCALL(hypercall)			\
> > > > +ENTRY(HYPERVISOR_##hypercall)			\
> > > > +	mov r12, #__HYPERVISOR_##hypercall;	\
> > > > +	xen_hvc;							\
> > > > +	mov pc, lr;							\
> > > > +ENDPROC(HYPERVISOR_##hypercall)
> > > > +
> > > > +                .text
> > > > +
> > > > +HYPERCALL(xen_version);
> > > > +HYPERCALL(console_io);
> > > > +HYPERCALL(grant_table_op);
> > > > +HYPERCALL(sched_op);
> > > > +HYPERCALL(event_channel_op);
> > > > +HYPERCALL(hvm_op);
> > > > +HYPERCALL(memory_op);
> > > > +HYPERCALL(physdev_op);
> > > > +
> > > > +ENTRY(privcmd_call)
> > > > +	stmdb	sp!, {r4}
> > > > +	mov r12, r0
> > > > +	mov r0, r1
> > > > +	mov r1, r2
> > > > +	mov r2, r3
> > > > +	ldr r3, [sp, #8]
> > > > +	ldr r4, [sp, #4]
> > > > +	xen_hvc
> > > > +	pop {r4}
> > 
> > Why not ldmdb for symmetry?
> 
> Yep, I can do that.

Stefano Stabellini

2012-Jul-27 13:41 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, 27 Jul 2012, Ian Campbell wrote:> > > > Should this comment be by ''privcmd_call''?
> > > 
> > > When we add a 5 argument hypercall I suppose we''ll see
the required
> > > push/pop of r4 added to this macro too.
> > 
> > For performance and simplicity I would add a second macro that
push/pop
> > r4, only required for hypercalls with more than 4 arguments.
> 
> For clarity / documentation purposes it might actually be worthwhile to
> define all of HYPERCALL{0,1,2,3,4} even if the {0,1,2,3} cases are all
> just:
>         #define HYPERCALL0(x) HYPERCALL_SIMPLE(x)
I agree
> > > > > +#define HYPERCALL(hypercall)			\
> > > > > +ENTRY(HYPERVISOR_##hypercall)			\
> > > > > +	mov r12, #__HYPERVISOR_##hypercall;	\
> > > > > +	xen_hvc;							\
> > > > > +	mov pc, lr;							\
> > > > > +ENDPROC(HYPERVISOR_##hypercall)
> > > > > +
> > > > > +                .text
> > > > > +
> > > > > +HYPERCALL(xen_version);
> > > > > +HYPERCALL(console_io);
> > > > > +HYPERCALL(grant_table_op);
> > > > > +HYPERCALL(sched_op);
> > > > > +HYPERCALL(event_channel_op);
> > > > > +HYPERCALL(hvm_op);
> > > > > +HYPERCALL(memory_op);
> > > > > +HYPERCALL(physdev_op);
> > > > > +
> > > > > +ENTRY(privcmd_call)
> > > > > +	stmdb	sp!, {r4}
> > > > > +	mov r12, r0
> > > > > +	mov r0, r1
> > > > > +	mov r1, r2
> > > > > +	mov r2, r3
> > > > > +	ldr r3, [sp, #8]
> > > > > +	ldr r4, [sp, #4]
> > > > > +	xen_hvc
> > > > > +	pop {r4}
> > > 
> > > Why not ldmdb for symmetry?
> > 
> > Yep, I can do that.
Actually it is just ldm or ldmia

Stefano Stabellini

2012-Jul-27 13:47 UTC

head link

Re: [Xen-devel] [PATCH 03/24] xen/arm: page.h definitions

On Thu, 26 Jul 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:45PM +0100, Stefano Stabellini wrote:
> > ARM Xen guests always use paging in hardware, like PV on HVM guests in
> > the X86 world.
> 
> Nice, so no dealing with the P2M at all in the guest?
Nope ;-)

> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > ---
> >  arch/arm/include/asm/xen/page.h |   77
+++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 77 insertions(+), 0 deletions(-)
> >  create mode 100644 arch/arm/include/asm/xen/page.h
> > 
> > diff --git a/arch/arm/include/asm/xen/page.h
b/arch/arm/include/asm/xen/page.h
> > new file mode 100644
> > index 0000000..6cfe9a1
> > --- /dev/null
> > +++ b/arch/arm/include/asm/xen/page.h
> > @@ -0,0 +1,77 @@
> > +#ifndef _ASM_ARM_XEN_PAGE_H
> > +#define _ASM_ARM_XEN_PAGE_H
> > +
> > +#include <asm/page.h>
> > +#include <linux/pfn.h>
> > +#include <linux/types.h>
> > +#include <asm/pgtable.h>
> > +#include <xen/interface/grant_table.h>
> 
> I don''t if it makes such a difference, but putting the headers in
sorted
> order is sometimes nicer than just randomly.. But that might be just
> me liking an orderly world nowadays :-)
I can do that

> > +
> > +#define pfn_to_mfn(pfn)			(pfn)
> > +#define phys_to_machine_mapping_valid	(1)
> > +#define mfn_to_pfn(mfn)			(mfn)
> > +#define mfn_to_virt(m)			(__va(mfn_to_pfn(m) << PAGE_SHIFT))
> > +
> > +#define pte_mfn	    pte_pfn
> > +#define mfn_pte	    pfn_pte
> > +
> > +/* Xen machine address */
> > +typedef struct xmaddr {
> > +	phys_addr_t maddr;
> > +} xmaddr_t;
> > +
> > +/* Xen pseudo-physical address */
> > +typedef struct xpaddr {
> > +	phys_addr_t paddr;
> > +} xpaddr_t;
> > +
> > +#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
> > +#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })
> > +
> > +static inline xmaddr_t phys_to_machine(xpaddr_t phys)
> > +{
> > +	unsigned offset = phys.paddr & ~PAGE_MASK;
> > +	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
> > +}
> > +
> > +static inline xpaddr_t machine_to_phys(xmaddr_t machine)
> > +{
> > +	unsigned offset = machine.maddr & ~PAGE_MASK;
> > +	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) |
offset);
> > +}
> > +/* VIRT <-> MACHINE conversion */
> > +#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
> > +#define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
> > +#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
> > +#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))
> > +
> > +static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
> > +{
> > +	/* XXX: assuming it is mapped in the kernel 1:1 */
> > +	return virt_to_machine(vaddr);
> > +}
> > +
> > +/* XXX: this shouldn''t be here */
> 
> So why is it here?
lookup_address shouldn''t be here because it is an x86-only interface.
However both gntdev.c and xenbus_client.c call it (in PV only code paths
that are never taken in a PV on HVM guest), so in order to compile them
I have to define lookup_address.

> > +static inline pte_t *lookup_address(unsigned long address, unsigned
int *level)
> > +{
> > +	BUG();
> > +	return NULL;
> > +}
> > +
> > +static inline int m2p_add_override(unsigned long mfn, struct page
*page,
> > +		struct gnttab_map_grant_ref *kmap_op)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline int m2p_remove_override(struct page *page, bool
clear_pte)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline bool set_phys_to_machine(unsigned long pfn, unsigned
long mfn)
> > +{
> > +	BUG();
> > +	return false;
> > +}
> > +#endif /* _ASM_ARM_XEN_PAGE_H */

Stefano Stabellini

2012-Jul-27 13:57 UTC

head link

Re: [PATCH 02/24] xen/arm: hypercalls

On Fri, 27 Jul 2012, Christopher Covington wrote:> On 07/27/2012 05:19 AM, Ian Campbell wrote:
> > On Thu, 2012-07-26 at 20:19 +0100, Christopher Covington wrote:
> >> Hi Stefano,
> >>
> >> On 07/26/2012 11:33 AM, Stefano Stabellini wrote:
> >>> Use r12 to pass the hypercall number to the hypervisor.
> >>>
> >>> We need a register to pass the hypercall number because we
might not
> >>> know it at compile time and HVC only takes an immediate
argument.
> >>
> >> You''re not going to JIT assemble the appropriate HVC
instruction? Darn.
> > 
> > ;-)
> > 
I admit having spent few hours thinking about how to implement a
self-modifying function able to change the ISS at run time. Fortunately
few hours later I was struck by common sense and I decided to follow a
different direction ;-)

> > The maximum currently defined hypercall number is 55, although there
are
> > some small gaps so there''s actually more like 45 in total.
> > 
> >>  It seems like it''d be
> >> reasonable to take the approach that seems to be favored for
MRC/MCR
> >> instructions, using a function containing switch statement that
chooses
> >> between several inline assembly instructions based off an enum
passed to
> >> the function. See for example arch_timer_reg_read in
> >> arch/arm/kernel/arch_timer.c.
> > 
> > I don''t think it is feasible with this number of hypercalls,
even
> > accepting that in many cases the number will be a constant so gcc can
> > likely optimise almost all of it away.
> > 
> > Is there something wrong with the r12 based approach?
> 
> Only that you''re defining a custom interface for something that
there is
> a potentially more standard interface for. I just wanted to double check
> that all the ways of using the potentially more standard interface had
> been explored and found to be unreasonable.
Yep, thanks for helping us reviewing the code.

Stefano Stabellini

2012-Jul-27 14:10 UTC

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Re: [Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

On Fri, 27 Jul 2012, Jan Beulich wrote:> >>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org> wrote:
> > In order for privcmd mmap to work correctly,
xen_remap_domain_mfn_range
> > needs to be implemented for HVM guests.
> > If it is not, mmap is going to fail later on.
> 
> Somehow, for me at least, this description doesn''t connect to the
> actual change.
We can remove the "return -ENOSYS" from privcmd_mmap but the actual
mmap
is still not going to work unless xen_remap_domain_mfn_range is
implemented correctly.
The x86 implementation of xen_remap_domain_mfn_range is PV only so it is
not going to work for HVM or auto_translated_physmap guests.
As a result mmap_batch_fn is going to fail.

> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > ---
> >  drivers/xen/privcmd.c |    4 ----
> >  1 files changed, 0 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> > index ccee0f1..85226cb 100644
> > --- a/drivers/xen/privcmd.c
> > +++ b/drivers/xen/privcmd.c
> > @@ -380,10 +380,6 @@ static struct vm_operations_struct privcmd_vm_ops
= {
> >  
> >  static int privcmd_mmap(struct file *file, struct vm_area_struct
*vma)
> >  {
> > -	/* Unsupported for auto-translate guests. */
> > -	if (xen_feature(XENFEAT_auto_translated_physmap))
> > -		return -ENOSYS;
> > -
> 
> Is this safe on x86?
> 
It is safe in the sense that is not going to crash dom0 or the
hypervisor, but it is not going to work.

Actually in order for it to be safe we need this additional change:

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 3a73785..885a223 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2310,6 +2310,9 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 	unsigned long range;
 	int err = 0;
 
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return -EINVAL;
+
 	prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP);
 
 	BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_RESERVED | VM_IO)) ==

Russell King - ARM Linux

2012-Jul-27 14:21 UTC

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Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, Jul 27, 2012 at 02:02:18PM +0100, Stefano Stabellini
wrote:> > > >
+/******************************************************************************
> > > > + * hypercall.h
> > > > + *
> > > > + * Linux-specific hypervisor handling.
> > > > + *
> > > > + * Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>, Citrix, 2012
> > > > + *
> > > > + * This program is free software; you can redistribute it
and/or
> > > > + * modify it under the terms of the GNU General Public
License version 2
> > > > + * as published by the Free Software Foundation; or, when
distributed
> > > > + * separately from the Linux kernel or incorporated into
other
> > > > + * software packages, subject to the following license:
> > > > + *
> > > > + * Permission is hereby granted, free of charge, to any
person obtaining a copy
> > > > + * of this source file (the "Software"), to deal
in the Software without
Erm, is that an additional restriction on the GPL which prevents me from
shipping this code on a CD and charging for the act of creating the CD
and shipping it?  That would technically make the above statement
incompatible with the GPL.

Stefano Stabellini

2012-Jul-27 14:25 UTC

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Re: [PATCH 13/24] xen/arm: get privilege status

On Fri, 27 Jul 2012, Ian Campbell wrote:> On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > Use Xen features to figure out if we are privileged.
> > 
> > XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/xen/enlighten.c         |    7 +++++++
> >  include/xen/interface/features.h |    3 +++
> >  2 files changed, 10 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index dc68074..2e013cf 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -2,6 +2,7 @@
> >  #include <xen/interface/xen.h>
> >  #include <xen/interface/memory.h>
> >  #include <xen/platform_pci.h>
> > +#include <xen/features.h>
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> >  #include <linux/module.h>
> > @@ -58,6 +59,12 @@ int __init xen_guest_init(void)
> >  	}
> >  	xen_domain_type = XEN_HVM_DOMAIN;
> >  
> > +	xen_setup_features();
> > +	if (xen_feature(XENFEAT_dom0))
> > +		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
> > +	else
> > +		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
> 
> What happens here on platforms prior to hypervisor changeset 23735?
It wouldn''t work.
Considering that we are certainly not going to backport ARM support to
Xen 4.1, and that both ARM and XENFEAT_dom0 will be present in Xen 4.2,
do we really need to support the Xen unstable changesets between ARM was
introduced and XENFEAT_dom0 appeared?

Ian Campbell

2012-Jul-27 14:33 UTC

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Re: [PATCH 13/24] xen/arm: get privilege status

On Fri, 2012-07-27 at 15:25 +0100, Stefano Stabellini
wrote:> On Fri, 27 Jul 2012, Ian Campbell wrote:
> > On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > > Use Xen features to figure out if we are privileged.
> > > 
> > > XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.
> > > 
> > > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > > ---
> > >  arch/arm/xen/enlighten.c         |    7 +++++++
> > >  include/xen/interface/features.h |    3 +++
> > >  2 files changed, 10 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > > index dc68074..2e013cf 100644
> > > --- a/arch/arm/xen/enlighten.c
> > > +++ b/arch/arm/xen/enlighten.c
> > > @@ -2,6 +2,7 @@
> > >  #include <xen/interface/xen.h>
> > >  #include <xen/interface/memory.h>
> > >  #include <xen/platform_pci.h>
> > > +#include <xen/features.h>
> > >  #include <asm/xen/hypervisor.h>
> > >  #include <asm/xen/hypercall.h>
> > >  #include <linux/module.h>
> > > @@ -58,6 +59,12 @@ int __init xen_guest_init(void)
> > >  	}
> > >  	xen_domain_type = XEN_HVM_DOMAIN;
> > >  
> > > +	xen_setup_features();
> > > +	if (xen_feature(XENFEAT_dom0))
> > > +		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
> > > +	else
> > > +		xen_start_info->flags &=
~(SIF_INITDOMAIN|SIF_PRIVILEGED);
> > 
> > What happens here on platforms prior to hypervisor changeset 23735?
> 
> It wouldn''t work.
> Considering that we are certainly not going to backport ARM support to
> Xen 4.1, and that both ARM and XENFEAT_dom0 will be present in Xen 4.2,
> do we really need to support the Xen unstable changesets between ARM was
> introduced and XENFEAT_dom0 appeared?
Sorry, I missed the "arm" in the path.

Ian.

Stefano Stabellini

2012-Jul-27 14:36 UTC

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Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, 27 Jul 2012, Russell King - ARM Linux wrote:> On Fri, Jul 27, 2012 at 02:02:18PM +0100, Stefano Stabellini wrote:
> > > > >
+/******************************************************************************
> > > > > + * hypercall.h
> > > > > + *
> > > > > + * Linux-specific hypervisor handling.
> > > > > + *
> > > > > + * Stefano Stabellini
<stefano.stabellini@eu.citrix.com>, Citrix, 2012
> > > > > + *
> > > > > + * This program is free software; you can redistribute
it and/or
> > > > > + * modify it under the terms of the GNU General Public
License version 2
> > > > > + * as published by the Free Software Foundation; or,
when distributed
> > > > > + * separately from the Linux kernel or incorporated
into other
> > > > > + * software packages, subject to the following
license:
> > > > > + *
> > > > > + * Permission is hereby granted, free of charge, to
any person obtaining a copy
> > > > > + * of this source file (the "Software"), to
deal in the Software without
> 
> Erm, is that an additional restriction on the GPL which prevents me from
> shipping this code on a CD and charging for the act of creating the CD
> and shipping it?  That would technically make the above statement
> incompatible with the GPL.
IMNAL but this is just an alternative, less strict, MIT license for this
file, same as the x86 counterpart
(arch/x86/include/asm/xen/hypercall.h). The intent is to allow other
operating systems, the BSDs for example, to be able to use it if they
want to.
Actually, given that the ARM implementation is not inline, I should
remember to add this copyright header to the assembly source file too.

Ian Campbell

2012-Jul-27 14:39 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, 2012-07-27 at 15:21 +0100, Russell King - ARM Linux
wrote:> On Fri, Jul 27, 2012 at 02:02:18PM +0100, Stefano Stabellini wrote:
> > > > >
+/******************************************************************************
> > > > > + * hypercall.h
> > > > > + *
> > > > > + * Linux-specific hypervisor handling.
> > > > > + *
> > > > > + * Stefano Stabellini
<stefano.stabellini@eu.citrix.com>, Citrix, 2012
> > > > > + *
> > > > > + * This program is free software; you can redistribute
it and/or
> > > > > + * modify it under the terms of the GNU General Public
License version 2
> > > > > + * as published by the Free Software Foundation; or,
when distributed
> > > > > + * separately from the Linux kernel or incorporated
into other
> > > > > + * software packages, subject to the following
license:
> > > > > + *
> > > > > + * Permission is hereby granted, free of charge, to
any person obtaining a copy
> > > > > + * of this source file (the "Software"), to
deal in the Software without
> 
> Erm, is that an additional restriction on the GPL which prevents me from
> shipping this code on a CD and charging for the act of creating the CD
> and shipping it?  That would technically make the above statement
> incompatible with the GPL.
There''s an "or" in there.

The non-GPL alternative license is the standard one applied by upstream
Xen to the interface headers:
       
http://xenbits.xen.org/hg/xen-unstable.hg/file/tip/xen/include/public/COPYING

It''s the X11/MIT license IIRC, which the FSF say is GPL compatible.
http://www.gnu.org/licenses/license-list.html#X11License

The same license is used a few other places in the kernel, e.g. the DRM
code.

Ian.

Stefano Stabellini

2012-Jul-27 14:48 UTC

head link

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

On Fri, 27 Jul 2012, Ian Campbell wrote:> On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > Check for a "/xen" node in the device tree, if it is present
set
> > xen_domain_type to XEN_HVM_DOMAIN and continue initialization.
> > 
> > Map the real shared info page using XENMEM_add_to_physmap with
> > XENMAPSPACE_shared_info.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/xen/enlighten.c |   56
++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 56 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index d27c2a6..8c923af 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -5,6 +5,9 @@
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> >  #include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/of_address.h>
> >  
> >  struct start_info _xen_start_info;
> >  struct start_info *xen_start_info = &_xen_start_info;
> > @@ -33,3 +36,56 @@ int xen_remap_domain_mfn_range(struct
vm_area_struct *vma,
> >  	return -ENOSYS;
> >  }
> >  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> > +
> > +/*
> > + * == Xen Device Tree format => > + * - /xen node;
> > + * - compatible "arm,xen";
> > + * - one interrupt for Xen event notifications;
> > + * - one memory region to map the grant_table.
> > + */
> > +static int __init xen_guest_init(void)
> > +{
> > +	int cpu;
> > +	struct xen_add_to_physmap xatp;
> > +	static struct shared_info *shared_info_page = 0;
> > +	struct device_node *node;
> > +
> > +	node = of_find_compatible_node(NULL, NULL, "arm,xen");
> > +	if (!node) {
> > +		pr_info("No Xen support\n");
> > +		return 0;
> > +	}
> 
> This should either only print in the success case (to avoid spamming
> everyone) or we need a little bit of infrastructure like on x86 so that
> we print exactly one of:
> 	"Booting natively on bearmetal"
> 	"Booting paravirtualised on %s", hypervisor->name
This function is only going to be called once (actually it might be
called twice with the change introduced by "xen/arm: Introduce
xen_guest_init").

I thought that it would be an acceptible level of verbosity for pr_info.
Maybe I should just turn the pr_info into pr_debug?

> > +	xen_domain_type = XEN_HVM_DOMAIN;
> > +
> > +	if (!shared_info_page)
> > +		shared_info_page = (struct shared_info *)
> > +			get_zeroed_page(GFP_KERNEL);
> > +	if (!shared_info_page) {
> > +		pr_err("not enough memory");
> > +		return -ENOMEM;
> > +	}
> > +	xatp.domid = DOMID_SELF;
> > +	xatp.idx = 0;
> > +	xatp.space = XENMAPSPACE_shared_info;
> > +	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> > +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> > +		BUG();
> > +
> > +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> > +
> > +	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
> > +	 * page, we use it in the event channel upcall and in some pvclock
> > +	 * related functions. We don''t need the vcpu_info placement
> > +	 * optimizations because we don''t use any pv_mmu or pv_irq
op on
> > +	 * HVM.
> > +	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
> > +	 * online but xen_hvm_init_shared_info is run at resume time too and
> > +	 * in that case multiple vcpus might be online. */
> > +	for_each_online_cpu(cpu) {
> > +		per_cpu(xen_vcpu, cpu) > > +		
&HYPERVISOR_shared_info->vcpu_info[cpu];
> 
> On ARM the shared info contains exactly 1 CPU (the boot CPU). The guest
> is required to use VCPUOP_register_vcpu_info to place vcpu info for
> secondary CPUs as they are brought up.
OK

Ian Campbell

2012-Jul-27 14:51 UTC

head link

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

On Fri, 2012-07-27 at 15:48 +0100, Stefano Stabellini
wrote:> On Fri, 27 Jul 2012, Ian Campbell wrote:
> > On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > > Check for a "/xen" node in the device tree, if it is
present set
> > > xen_domain_type to XEN_HVM_DOMAIN and continue initialization.
> > > 
> > > Map the real shared info page using XENMEM_add_to_physmap with
> > > XENMAPSPACE_shared_info.
> > > 
> > > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > > ---
> > >  arch/arm/xen/enlighten.c |   56
++++++++++++++++++++++++++++++++++++++++++++++
> > >  1 files changed, 56 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > > index d27c2a6..8c923af 100644
> > > --- a/arch/arm/xen/enlighten.c
> > > +++ b/arch/arm/xen/enlighten.c
> > > @@ -5,6 +5,9 @@
> > >  #include <asm/xen/hypervisor.h>
> > >  #include <asm/xen/hypercall.h>
> > >  #include <linux/module.h>
> > > +#include <linux/of.h>
> > > +#include <linux/of_irq.h>
> > > +#include <linux/of_address.h>
> > >  
> > >  struct start_info _xen_start_info;
> > >  struct start_info *xen_start_info = &_xen_start_info;
> > > @@ -33,3 +36,56 @@ int xen_remap_domain_mfn_range(struct
vm_area_struct *vma,
> > >  	return -ENOSYS;
> > >  }
> > >  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> > > +
> > > +/*
> > > + * == Xen Device Tree format => > > + * - /xen node;
> > > + * - compatible "arm,xen";
> > > + * - one interrupt for Xen event notifications;
> > > + * - one memory region to map the grant_table.
> > > + */
> > > +static int __init xen_guest_init(void)
> > > +{
> > > +	int cpu;
> > > +	struct xen_add_to_physmap xatp;
> > > +	static struct shared_info *shared_info_page = 0;
> > > +	struct device_node *node;
> > > +
> > > +	node = of_find_compatible_node(NULL, NULL,
"arm,xen");
> > > +	if (!node) {
> > > +		pr_info("No Xen support\n");
> > > +		return 0;
> > > +	}
> > 
> > This should either only print in the success case (to avoid spamming
> > everyone) or we need a little bit of infrastructure like on x86 so
that
> > we print exactly one of:
> > 	"Booting natively on bearmetal"
> > 	"Booting paravirtualised on %s", hypervisor->name
> 
> This function is only going to be called once (actually it might be
> called twice with the change introduced by "xen/arm: Introduce
> xen_guest_init").
Once (or twice), per boot, per ARM system running Linux in the world...

Ian.

Russell King - ARM Linux

2012-Jul-27 14:59 UTC

head link

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

On Fri, Jul 27, 2012 at 03:39:31PM +0100, Ian Campbell
wrote:> On Fri, 2012-07-27 at 15:21 +0100, Russell King - ARM Linux wrote:
> > On Fri, Jul 27, 2012 at 02:02:18PM +0100, Stefano Stabellini wrote:
> > > > > >
+/******************************************************************************
> > > > > > + * hypercall.h
> > > > > > + *
> > > > > > + * Linux-specific hypervisor handling.
> > > > > > + *
> > > > > > + * Stefano Stabellini
<stefano.stabellini@eu.citrix.com>, Citrix, 2012
> > > > > > + *
> > > > > > + * This program is free software; you can
redistribute it and/or
> > > > > > + * modify it under the terms of the GNU General
Public License version 2
> > > > > > + * as published by the Free Software Foundation;
or, when distributed
> > > > > > + * separately from the Linux kernel or
incorporated into other
> > > > > > + * software packages, subject to the following
license:
> > > > > > + *
> > > > > > + * Permission is hereby granted, free of charge,
to any person obtaining a copy
> > > > > > + * of this source file (the
"Software"), to deal in the Software without
> > 
> > Erm, is that an additional restriction on the GPL which prevents me
from
> > shipping this code on a CD and charging for the act of creating the CD
> > and shipping it?  That would technically make the above statement
> > incompatible with the GPL.
> 
> There''s an "or" in there.
> 
> The non-GPL alternative license is the standard one applied by upstream
> Xen to the interface headers:
>        
http://xenbits.xen.org/hg/xen-unstable.hg/file/tip/xen/include/public/COPYING
> 
> It''s the X11/MIT license IIRC, which the FSF say is GPL
compatible.
> http://www.gnu.org/licenses/license-list.html#X11License
> 
> The same license is used a few other places in the kernel, e.g. the DRM
> code.
Ok, but be aware that you won''t be able to take code from the Linux
kernel and place it in a file marked with that license header (because
the code authors haven''t given permission for it to be placed under any
other license other than GPLv2.)

Stefano Stabellini

2012-Jul-27 15:54 UTC

head link

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

On Fri, 27 Jul 2012, Ian Campbell wrote:> On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > We used to rely on a core_initcall to initialize Xen on ARM, however
> > core_initcalls are actually called after early consoles are
initialized.
> > That means that hvc_xen.c is going to be initialized before Xen.
> > 
> > Given the lack of a better alternative, just call a new Xen
> > initialization function (xen_guest_init) from xen_cons_init.
> 
> Can''t we just arrange for this to be called super early on from
> setup_arch? That''s got to be better than calling it from some
random
> function which happens to get called early enough.
While I agree with you that an explicit call to xen_guest_init from
generic code might be better, xen_cons_init is not just a random
function: it is a console_initcall and therefore we know for sure that
it is going be the first one to be called.

In fact if we didn''t want the PV console to work so early we could just
rely on a core_initcall to initialize everything and we wouldn''t have
any issues.


In any case if the ARM maintainers agree I could add a generic
hypervisor initialization call the end of setup_arch.


> I presume that KVM is going to want some similarly early init hooks etc
> and therefore ARM could benefit from the same sort of infrastructure as
> is in arch/x86/include/asm/hypervisor.h?

Ian Campbell

2012-Jul-27 16:11 UTC

head link

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

On Fri, 2012-07-27 at 16:54 +0100, Stefano Stabellini
wrote:> On Fri, 27 Jul 2012, Ian Campbell wrote:
> > On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > > We used to rely on a core_initcall to initialize Xen on ARM,
however
> > > core_initcalls are actually called after early consoles are
initialized.
> > > That means that hvc_xen.c is going to be initialized before Xen.
> > > 
> > > Given the lack of a better alternative, just call a new Xen
> > > initialization function (xen_guest_init) from xen_cons_init.
> > 
> > Can''t we just arrange for this to be called super early on
from
> > setup_arch? That''s got to be better than calling it from some
random
> > function which happens to get called early enough.
> 
> While I agree with you that an explicit call to xen_guest_init from
> generic code might be better, xen_cons_init is not just a random
> function: it is a console_initcall and therefore we know for sure that
> it is going be the first one to be called.
Initialising something != console in a console_initcall just because it
happens to be called early enough meets my definition of calling it from
a random place.
> In fact if we didn''t want the PV console to work so early we could
just
> rely on a core_initcall to initialize everything and we wouldn''t
have
> any issues.
> 
> 
> In any case if the ARM maintainers agree I could add a generic
> hypervisor initialization call the end of setup_arch.
> 
> 
> 
> > I presume that KVM is going to want some similarly early init hooks
etc
> > and therefore ARM could benefit from the same sort of infrastructure
as
> > is in arch/x86/include/asm/hypervisor.h?

Stefano Stabellini

2012-Jul-27 16:25 UTC

head link

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

On Fri, 27 Jul 2012, Ian Campbell wrote:> On Thu, 2012-07-26 at 16:34 +0100, Stefano Stabellini wrote:
> > 
> > +#define XEN_IO_PROTO_ABI_ARM        "arm-abi" 
> 
> I wonder if we ought to call this arm-aarch32-abi or something?
So aarch64 has just been renamed to arm64 and you want to rename arm-abi
to aarch32-abi? :-)

> I wonder if we can also take the opportunity to fix the ABI cockup for
> disks on ARM and make the structs the same for both 32 and 64 bit?
I think it should be a separate patch, but I''ll try to come up with one

Stefano Stabellini

2012-Jul-27 16:47 UTC

head link

Re: [Xen-devel] [PATCH 06/24] xen: missing includes

On Fri, 27 Jul 2012, Jan Beulich wrote:> >>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> > --- a/include/xen/interface/xen.h
> > +++ b/include/xen/interface/xen.h
> > @@ -10,7 +10,10 @@
> >  #define __XEN_PUBLIC_XEN_H__
> >  
> >  #include <asm/xen/interface.h>
> > +#include <linux/types.h>
> > +#ifdef CONFIG_X86
> >  #include <asm/pvclock-abi.h>
> > +#endif
> 
> Rather than hacking around this, why not clean it up:
> asm/pvclock-abi.h clearly isn''t intended to be included here
> (from the perspective of the origin of xen/interface/xen.h, at
> least), nor is linux/types.h.
> 
> Or if it is really needed to deviate from the original header in
> this respect, then clearly the inclusion ought to not be arch
> specific or be moved to an arch specific header.
I think you are right: linux/types.h is not actually needed and
pvclock-abi.h should probably be included by asm/xen/interface.h.

Stefano Stabellini

2012-Jul-27 16:51 UTC

head link

Re: [Xen-devel] [PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM

On Fri, 27 Jul 2012, Jan Beulich wrote:> >>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> > --- a/drivers/xen/Makefile
> > +++ b/drivers/xen/Makefile
> > @@ -1,11 +1,15 @@
> > -obj-y	+= grant-table.o features.o events.o manage.o balloon.o
> > +ifneq ($(CONFIG_ARM),y)
> > +obj-y	+= manage.o balloon.o
> 
> While I assume that this part (and the cpu_hotplug one below) is
> temporary, ...
> 
> > +obj-$(CONFIG_XEN_DOM0)			+= pci.o acpi.o
> 
> ... at least this one should imo be solved with a proper long term
> mechanism, i.e. the usual var-$(CONFIG_...) approach, i.e.
> 
> dom0-$(CONFIG_PCI) := pci.o
> dom0-$(CONFIG_ACPI) := acpi.o
> obj-$(CONFIG_XEN_DOM0)			+= $(dom0-y)
That''s a good suggestion, thanks!

Konrad Rzeszutek Wilk

2012-Aug-01 10:42 UTC

head link

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

> > > +struct pvclock_wall_clock {
> > > +	u32   version;
> > > +	u32   sec;
> > > +	u32   nsec;
> > > +} __attribute__((__packed__));
> > 
> > That is weird. It is 4+4+4 = 12 bytes? Don''t you want it to
be 16 bytes?
> 
> I agree that 16 bytes would be a better choice, but it needs to match
> the struct in Xen that is defined as follow:
> 
>     uint32_t wc_version;      /* Version counter: see vcpu_time_info_t. */
>     uint32_t wc_sec;          /* Secs  00:00:00 UTC, Jan 1, 1970.  */
>     uint32_t wc_nsec;         /* Nsecs 00:00:00 UTC, Jan 1, 1970.  */
Would it make sense to add some paddigin then at least? In both
cases? Or is it too late for this?

Konrad Rzeszutek Wilk

2012-Aug-01 14:16 UTC

head link

Re: [PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions

On Thu, Jul 26, 2012 at 04:33:47PM +0100, Stefano Stabellini
wrote:> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/Makefile      |    2 +-
>  arch/arm/xen/grant-table.c |   53
++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 54 insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/xen/grant-table.c
> 
> diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> index b9d6acc..4384103 100644
> --- a/arch/arm/xen/Makefile
> +++ b/arch/arm/xen/Makefile
> @@ -1 +1 @@
> -obj-y		:= enlighten.o hypercall.o
> +obj-y		:= enlighten.o hypercall.o grant-table.o
> diff --git a/arch/arm/xen/grant-table.c b/arch/arm/xen/grant-table.c
> new file mode 100644
> index 0000000..0a4ee80
> --- /dev/null
> +++ b/arch/arm/xen/grant-table.c
> @@ -0,0 +1,53 @@
>
+/******************************************************************************
> + * grant_table.c
> + * ARM specific part
> + *
> + * Granting foreign access to our memory reservation.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation; or, when distributed
> + * separately from the Linux kernel or incorporated into other
> + * software packages, subject to the following license:
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
copy
> + * of this source file (the "Software"), to deal in the Software
without
> + * restriction, including without limitation the rights to use, copy,
modify,
> + * merge, publish, distribute, sublicense, and/or sell copies of the
Software,
> + * and to permit persons to whom the Software is furnished to do so,
subject to
> + * the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included
in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include <xen/interface/xen.h>
> +#include <xen/page.h>
> +#include <xen/grant_table.h>
> +
> +int arch_gnttab_map_shared(unsigned long *frames, unsigned long
nr_gframes,
> +			   unsigned long max_nr_gframes,
> +			   void **__shared)
> +{
> +	return -1;
-ENOSYS> +}
> +
> +void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
> +{
> +	return;
> +}
> +
> +int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
> +			   unsigned long max_nr_gframes,
> +			   grant_status_t **__shared)
> +{
> +	return -1;
Same here -ENOSYS> +}
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:19 UTC

head link

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

On Thu, Jul 26, 2012 at 04:33:49PM +0100, Stefano Stabellini
wrote:> Check for a "/xen" node in the device tree, if it is present set
> xen_domain_type to XEN_HVM_DOMAIN and continue initialization.
> 
> Map the real shared info page using XENMEM_add_to_physmap with
> XENMAPSPACE_shared_info.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c |   56
++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 56 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index d27c2a6..8c923af 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -5,6 +5,9 @@
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
>  
>  struct start_info _xen_start_info;
>  struct start_info *xen_start_info = &_xen_start_info;
> @@ -33,3 +36,56 @@ int xen_remap_domain_mfn_range(struct vm_area_struct
*vma,
>  	return -ENOSYS;
>  }
>  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> +
> +/*
> + * == Xen Device Tree format => + * - /xen node;
> + * - compatible "arm,xen";
> + * - one interrupt for Xen event notifications;
> + * - one memory region to map the grant_table.
> + */
> +static int __init xen_guest_init(void)
> +{
> +	int cpu;
> +	struct xen_add_to_physmap xatp;
> +	static struct shared_info *shared_info_page = 0;
> +	struct device_node *node;
> +
> +	node = of_find_compatible_node(NULL, NULL, "arm,xen");
> +	if (!node) {
> +		pr_info("No Xen support\n");
I don''t think the pr_info is appropiate here?> +		return 0;
Should this be -ENODEV?
> +	}
> +	xen_domain_type = XEN_HVM_DOMAIN;
> +
> +	if (!shared_info_page)
> +		shared_info_page = (struct shared_info *)
> +			get_zeroed_page(GFP_KERNEL);
> +	if (!shared_info_page) {
> +		pr_err("not enough memory");
\n
> +		return -ENOMEM;
> +	}
> +	xatp.domid = DOMID_SELF;
> +	xatp.idx = 0;
> +	xatp.space = XENMAPSPACE_shared_info;
> +	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> +		BUG();
> +
> +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> +
> +	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
> +	 * page, we use it in the event channel upcall and in some pvclock
> +	 * related functions. We don''t need the vcpu_info placement
> +	 * optimizations because we don''t use any pv_mmu or pv_irq op on
> +	 * HVM.
> +	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
> +	 * online but xen_hvm_init_shared_info is run at resume time too and
> +	 * in that case multiple vcpus might be online. */
> +	for_each_online_cpu(cpu) {
> +		per_cpu(xen_vcpu, cpu) > +		
&HYPERVISOR_shared_info->vcpu_info[cpu];
> +	}
> +	return 0;
This above looks stringly similar to the x86 one. Could it be
abstracted away to share the same code? Or is that something that
ought to be done later on when there is more meat on the bone?

> +}
> +core_initcall(xen_guest_init);
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:22 UTC

head link

Re: [PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types

On Thu, Jul 26, 2012 at 04:33:50PM +0100, Stefano Stabellini
wrote:> All the original Xen headers have xen_pfn_t as mfn and pfn type, however
> when they have been imported in Linux, xen_pfn_t has been replaced with
> unsigned long. That might work for x86 and ia64 but it does not for arm.
How come?> Bring back xen_pfn_t and let each architecture define xen_pfn_t as they
> see fit.
I am OK with this as long as your include a comment in both of the
interface.h saying why this is needed. I am curious why ''unsinged
long''
won''t work? Is it b/c on ARM you always want a 64-bit type?
> 
> Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> ---
>  arch/arm/include/asm/xen/interface.h  |    2 ++
>  arch/ia64/include/asm/xen/interface.h |    2 +-
>  arch/x86/include/asm/xen/interface.h  |    2 ++
>  include/xen/interface/grant_table.h   |    4 ++--
>  include/xen/interface/memory.h        |    6 +++---
>  include/xen/interface/platform.h      |    4 ++--
>  include/xen/interface/xen.h           |    6 +++---
>  include/xen/privcmd.h                 |    2 --
>  8 files changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/arm/include/asm/xen/interface.h
b/arch/arm/include/asm/xen/interface.h
> index 6c3ab59..76b1ebe 100644
> --- a/arch/arm/include/asm/xen/interface.h
> +++ b/arch/arm/include/asm/xen/interface.h
> @@ -25,6 +25,7 @@
>  	} while (0)
>  
>  #ifndef __ASSEMBLY__
> +typedef uint64_t xen_pfn_t;
>  /* Guest handles for primitive C types. */
>  __DEFINE_GUEST_HANDLE(uchar, unsigned char);
>  __DEFINE_GUEST_HANDLE(uint,  unsigned int);
> @@ -35,6 +36,7 @@ DEFINE_GUEST_HANDLE(long);
>  DEFINE_GUEST_HANDLE(void);
>  DEFINE_GUEST_HANDLE(uint64_t);
>  DEFINE_GUEST_HANDLE(uint32_t);
> +DEFINE_GUEST_HANDLE(xen_pfn_t);
>  
>  /* Maximum number of virtual CPUs in multi-processor guests. */
>  #define MAX_VIRT_CPUS 1
> diff --git a/arch/ia64/include/asm/xen/interface.h
b/arch/ia64/include/asm/xen/interface.h
> index 09d5f7f..9efa068 100644
> --- a/arch/ia64/include/asm/xen/interface.h
> +++ b/arch/ia64/include/asm/xen/interface.h
> @@ -67,6 +67,7 @@
>  #define set_xen_guest_handle(hnd, val)	do { (hnd).p = val; } while (0)
>  
>  #ifndef __ASSEMBLY__
> +typedef unsigned long xen_pfn_t;
>  /* Guest handles for primitive C types. */
>  __DEFINE_GUEST_HANDLE(uchar, unsigned char);
>  __DEFINE_GUEST_HANDLE(uint, unsigned int);
> @@ -79,7 +80,6 @@ DEFINE_GUEST_HANDLE(void);
>  DEFINE_GUEST_HANDLE(uint64_t);
>  DEFINE_GUEST_HANDLE(uint32_t);
>  
> -typedef unsigned long xen_pfn_t;
>  DEFINE_GUEST_HANDLE(xen_pfn_t);
>  #define PRI_xen_pfn	"lx"
>  #endif
> diff --git a/arch/x86/include/asm/xen/interface.h
b/arch/x86/include/asm/xen/interface.h
> index cbf0c9d..24c1b07 100644
> --- a/arch/x86/include/asm/xen/interface.h
> +++ b/arch/x86/include/asm/xen/interface.h
> @@ -47,6 +47,7 @@
>  #endif
>  
>  #ifndef __ASSEMBLY__
> +typedef unsigned long xen_pfn_t;
>  /* Guest handles for primitive C types. */
>  __DEFINE_GUEST_HANDLE(uchar, unsigned char);
>  __DEFINE_GUEST_HANDLE(uint,  unsigned int);
> @@ -57,6 +58,7 @@ DEFINE_GUEST_HANDLE(long);
>  DEFINE_GUEST_HANDLE(void);
>  DEFINE_GUEST_HANDLE(uint64_t);
>  DEFINE_GUEST_HANDLE(uint32_t);
> +DEFINE_GUEST_HANDLE(xen_pfn_t);
>  #endif
>  
>  #ifndef HYPERVISOR_VIRT_START
> diff --git a/include/xen/interface/grant_table.h
b/include/xen/interface/grant_table.h
> index a17d844..7da811b 100644
> --- a/include/xen/interface/grant_table.h
> +++ b/include/xen/interface/grant_table.h
> @@ -338,7 +338,7 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_dump_table);
>  #define GNTTABOP_transfer                4
>  struct gnttab_transfer {
>      /* IN parameters. */
> -    unsigned long mfn;
> +    xen_pfn_t mfn;
>      domid_t       domid;
>      grant_ref_t   ref;
>      /* OUT parameters. */
> @@ -375,7 +375,7 @@ struct gnttab_copy {
>  	struct {
>  		union {
>  			grant_ref_t ref;
> -			unsigned long   gmfn;
> +			xen_pfn_t   gmfn;
>  		} u;
>  		domid_t  domid;
>  		uint16_t offset;
> diff --git a/include/xen/interface/memory.h
b/include/xen/interface/memory.h
> index eac3ce1..abbbff0 100644
> --- a/include/xen/interface/memory.h
> +++ b/include/xen/interface/memory.h
> @@ -31,7 +31,7 @@ struct xen_memory_reservation {
>       *   OUT: GMFN bases of extents that were allocated
>       *   (NB. This command also updates the mach_to_phys translation
table)
>       */
> -    GUEST_HANDLE(ulong) extent_start;
> +    GUEST_HANDLE(xen_pfn_t) extent_start;
>  
>      /* Number of extents, and size/alignment of each (2^extent_order
pages). */
>      unsigned long  nr_extents;
> @@ -130,7 +130,7 @@ struct xen_machphys_mfn_list {
>       * any large discontiguities in the machine address space, 2MB gaps in
>       * the machphys table will be represented by an MFN base of zero.
>       */
> -    GUEST_HANDLE(ulong) extent_start;
> +    GUEST_HANDLE(xen_pfn_t) extent_start;
>  
>      /*
>       * Number of extents written to the above array. This will be smaller
> @@ -172,7 +172,7 @@ struct xen_add_to_physmap {
>      unsigned long idx;
>  
>      /* GPFN where the source mapping page should appear. */
> -    unsigned long gpfn;
> +    xen_pfn_t gpfn;
>  };
>  DEFINE_GUEST_HANDLE_STRUCT(xen_add_to_physmap);
>  
> diff --git a/include/xen/interface/platform.h
b/include/xen/interface/platform.h
> index 486653f..0bea470 100644
> --- a/include/xen/interface/platform.h
> +++ b/include/xen/interface/platform.h
> @@ -54,7 +54,7 @@ DEFINE_GUEST_HANDLE_STRUCT(xenpf_settime_t);
>  #define XENPF_add_memtype         31
>  struct xenpf_add_memtype {
>  	/* IN variables. */
> -	unsigned long mfn;
> +	xen_pfn_t mfn;
>  	uint64_t nr_mfns;
>  	uint32_t type;
>  	/* OUT variables. */
> @@ -84,7 +84,7 @@ struct xenpf_read_memtype {
>  	/* IN variables. */
>  	uint32_t reg;
>  	/* OUT variables. */
> -	unsigned long mfn;
> +	xen_pfn_t mfn;
>  	uint64_t nr_mfns;
>  	uint32_t type;
>  };
> diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
> index 4f29f33..d59a991 100644
> --- a/include/xen/interface/xen.h
> +++ b/include/xen/interface/xen.h
> @@ -192,7 +192,7 @@ struct mmuext_op {
>  	unsigned int cmd;
>  	union {
>  		/* [UN]PIN_TABLE, NEW_BASEPTR, NEW_USER_BASEPTR */
> -		unsigned long mfn;
> +		xen_pfn_t mfn;
>  		/* INVLPG_LOCAL, INVLPG_ALL, SET_LDT */
>  		unsigned long linear_addr;
>  	} arg1;
> @@ -432,11 +432,11 @@ struct start_info {
>  	unsigned long nr_pages;     /* Total pages allocated to this domain.  */
>  	unsigned long shared_info;  /* MACHINE address of shared info struct. */
>  	uint32_t flags;             /* SIF_xxx flags.                         */
> -	unsigned long store_mfn;    /* MACHINE page number of shared page.    */
> +	xen_pfn_t store_mfn;        /* MACHINE page number of shared page.    */
>  	uint32_t store_evtchn;      /* Event channel for store communication. */
>  	union {
>  		struct {
> -			unsigned long mfn;  /* MACHINE page number of console page.   */
> +			xen_pfn_t mfn;      /* MACHINE page number of console page.   */
>  			uint32_t  evtchn;   /* Event channel for console page.        */
>  		} domU;
>  		struct {
> diff --git a/include/xen/privcmd.h b/include/xen/privcmd.h
> index 4d58881..45c1aa1 100644
> --- a/include/xen/privcmd.h
> +++ b/include/xen/privcmd.h
> @@ -37,8 +37,6 @@
>  #include <linux/compiler.h>
>  #include <xen/interface/xen.h>
>  
> -typedef unsigned long xen_pfn_t;
> -
>  struct privcmd_hypercall {
>  	__u64 op;
>  	__u64 arg[5];
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:28 UTC

head link

Re: [PATCH 09/24] xen/arm: compile and run xenbus

On Thu, Jul 26, 2012 at 04:33:51PM +0100, Stefano Stabellini
wrote:> bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not
> an error.
> 
> If Linux is running as an HVM domain and is running as Dom0, use
> xenstored_local_init to initialize the xenstore page and event channel.
> 
> Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> ---
>  drivers/xen/xenbus/xenbus_comms.c |    2 +-
>  drivers/xen/xenbus/xenbus_probe.c |   27 +++++++++++++++++----------
>  drivers/xen/xenbus/xenbus_xs.c    |    1 +
>  3 files changed, 19 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/xen/xenbus/xenbus_comms.c
b/drivers/xen/xenbus/xenbus_comms.c
> index 52fe7ad..c5aa55c 100644
> --- a/drivers/xen/xenbus/xenbus_comms.c
> +++ b/drivers/xen/xenbus/xenbus_comms.c
> @@ -224,7 +224,7 @@ int xb_init_comms(void)
>  		int err;
>  		err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
>  						0, "xenbus", &xb_waitq);
> -		if (err <= 0) {
> +		if (err < 0) {
>  			printk(KERN_ERR "XENBUS request irq failed %i\n", err);
>  			return err;
>  		}
> diff --git a/drivers/xen/xenbus/xenbus_probe.c
b/drivers/xen/xenbus/xenbus_probe.c
> index b793723..3ae47c2 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -729,16 +729,23 @@ static int __init xenbus_init(void)
>  	xenbus_ring_ops_init();
>  
>  	if (xen_hvm_domain()) {
> -		uint64_t v = 0;
> -		err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
> -		if (err)
> -			goto out_error;
> -		xen_store_evtchn = (int)v;
> -		err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> -		if (err)
> -			goto out_error;
> -		xen_store_mfn = (unsigned long)v;
> -		xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT,
PAGE_SIZE);
> +		if (xen_initial_domain()) {
> +			err = xenstored_local_init();
> +			xen_store_interface > +				phys_to_virt(xen_store_mfn <<
PAGE_SHIFT);
> +		} else {
> +			uint64_t v = 0;
> +			err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
> +			if (err)
> +				goto out_error;
> +			xen_store_evtchn = (int)v;
> +			err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> +			if (err)
> +				goto out_error;
> +			xen_store_mfn = (unsigned long)v;
> +			xen_store_interface > +				ioremap(xen_store_mfn <<
PAGE_SHIFT, PAGE_SIZE);
> +		}
This, and along with the Hybrid PV dom0 (not yet posted, but it was doing
similar manipulation here) is getting more and more like a rat-mess.


Any chance we can just abstract the three different XenStore access
ways and just have something like this:

	enum {
		USE_UNKNOWN
		USE_HVM,
		USE_PV,
		USE_LOCAL
		USE_ALREADY_INIT
	};
	int usage = USE_UNKNOWN;
	if (xen_pv_domain())
		usage = USE_PV;
	if (xen_hvm_domain())
		usage = USE_HVM;
	if (xen_initial_domain())
		usage = USE_LOCAL;

	if (xen_start_info->store_evtchn)
		usage = USE_ALREADY_INIT;
	
	.. other overwrites..

	switch (usage) {
		.. blah blah.
	}

>  		xen_store_evtchn = xen_start_info->store_evtchn;
>  		xen_store_mfn = xen_start_info->store_mfn;
> diff --git a/drivers/xen/xenbus/xenbus_xs.c
b/drivers/xen/xenbus/xenbus_xs.c
> index d1c217b..f7feb3d 100644
> --- a/drivers/xen/xenbus/xenbus_xs.c
> +++ b/drivers/xen/xenbus/xenbus_xs.c
> @@ -44,6 +44,7 @@
>  #include <linux/rwsem.h>
>  #include <linux/module.h>
>  #include <linux/mutex.h>
> +#include <asm/xen/hypervisor.h>
>  #include <xen/xenbus.h>
>  #include <xen/xen.h>
>  #include "xenbus_comms.h"
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:34 UTC

head link

Re: [Xen-devel] [PATCH 11/24] xen/arm: introduce CONFIG_XEN on ARM

On Thu, Jul 26, 2012 at 04:33:53PM +0100, Stefano Stabellini
wrote:> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/Kconfig |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index a91009c..9c54cb4 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -2228,6 +2228,16 @@ config NEON
>  	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
>  	  Extension.
>  
> +config XEN_DOM0
> +	def_bool y
What is the benefit of this ? I was hoping at some point to rip out all of those
XEN_DOM0 and just have, mostly,
	CONFIG_XEN_BACKEND_SUPPORT
		(which would compile whatever is needed for HVM or PV guests to run
		blkback/netback/grant/grantalloc/etc)
	CONFIG_XEN_FRONTEND_SUPPORT
		(the vice-versa)

	CONFIG_XEN_PCI
		which would have the PCI support, the ACPI routing (which is
		predomaintaly most of the dom0 support), VGA text support, and
		whatever else is in there.

In that fashion you could compile a kernel with CONFIG_XEN_BACKEND_SUPPORT
without any CONFIG_XEN_PCI and drop it in as an HVM device driver domain.
Thought maybe that wouldn''t really work as if you do PCI passthrough to
such
domain, you are going to need the PCI support and ACPI routing. The VGA text
maybe not...

OK, never mind - we should brainstorm it and figure out how to make this
nicely work. In the meantime this is OK.
> +
> +config XEN
> +	bool "Xen guest support on ARM"
> +	depends on ARM && OF
> +	select XEN_DOM0
> +	help
> +	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
> +
>  endmenu
>  
>  menu "Userspace binary formats"
> -- 
> 1.7.2.5
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Konrad Rzeszutek Wilk

2012-Aug-01 14:35 UTC

head link

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

On Fri, Jul 27, 2012 at 10:28:25AM +0100, Ian Campbell
wrote:> On Thu, 2012-07-26 at 17:37 +0100, Konrad Rzeszutek Wilk wrote:
> > On Thu, Jul 26, 2012 at 04:33:46PM +0100, Stefano Stabellini wrote:
> > > sync_bitops functions are equivalent to the SMP implementation of
the
> > > original functions, independently from CONFIG_SMP being defined.
> > 
> > So why can''t the code be changed to use that? Is it that
> > the _set_bit, _clear_bit, etc are not available with !CONFIG_SMP?
> 
> _set_bit etc are not SMP safe if !CONFIG_SMP. But under Xen you might be
> communicating with a completely external entity who might be on another
> CPU (e.g. two uniprocessor guests communicating via event channels and
> grant tables). So we need a variant of the bit ops which are SMP safe
> even on a UP kernel.
> 
> The users are common code and the sync_foo vs foo distinction matters on
> some platforms (e.g. x86 where a UP kernel would omit the LOCK prefix
> for the normal ones).
OK, that makes sense. Stefano can you include that comment in the git
commit description and in the sync_bitops.h file please?> 
> > 
> > > 
> > > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > > ---
> > >  arch/arm/include/asm/sync_bitops.h |   17 +++++++++++++++++
> > >  1 files changed, 17 insertions(+), 0 deletions(-)
> > >  create mode 100644 arch/arm/include/asm/sync_bitops.h
> > > 
> > > diff --git a/arch/arm/include/asm/sync_bitops.h
b/arch/arm/include/asm/sync_bitops.h
> > > new file mode 100644
> > > index 0000000..d975092903
> > > --- /dev/null
> > > +++ b/arch/arm/include/asm/sync_bitops.h
> > > @@ -0,0 +1,17 @@
> > > +#ifndef __ASM_SYNC_BITOPS_H__
> > > +#define __ASM_SYNC_BITOPS_H__
> > > +
> > > +#include <asm/bitops.h>
> > > +#include <asm/system.h>
> > > +
> > > +#define sync_set_bit(nr, p)		_set_bit(nr, p)
> > > +#define sync_clear_bit(nr, p)		_clear_bit(nr, p)
> > > +#define sync_change_bit(nr, p)		_change_bit(nr, p)
> > > +#define sync_test_and_set_bit(nr, p)	_test_and_set_bit(nr, p)
> > > +#define sync_test_and_clear_bit(nr, p)	_test_and_clear_bit(nr,
p)
> > > +#define sync_test_and_change_bit(nr, p)	_test_and_change_bit(nr,
p)
> > > +#define sync_test_bit(nr, addr)		test_bit(nr, addr)
> > > +#define sync_cmpxchg			cmpxchg
> > > +
> > > +
> > > +#endif
> > > -- 
> > > 1.7.2.5
> > > 
> > > 
> > > _______________________________________________
> > > Xen-devel mailing list
> > > Xen-devel-GuqFBffKawuEi8DpZVb4nw@public.gmane.org
> > > http://lists.xen.org/xen-devel
>

Konrad Rzeszutek Wilk

2012-Aug-01 14:38 UTC

head link

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

On Thu, Jul 26, 2012 at 04:33:54PM +0100, Stefano Stabellini
wrote:> We used to rely on a core_initcall to initialize Xen on ARM, however
> core_initcalls are actually called after early consoles are initialized.
> That means that hvc_xen.c is going to be initialized before Xen.
> 
> Given the lack of a better alternative, just call a new Xen
> initialization function (xen_guest_init) from xen_cons_init.
> 
> xen_guest_init has to be arch independent, so write both an ARM and an
> x86 implementation. The x86 implementation is currently empty because we
> can be sure that xen_hvm_guest_init is called early enough.
Should the arm version then not be anymore on the core_initcall then?
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c  |    7 ++++++-
>  arch/x86/xen/enlighten.c  |    8 ++++++++
>  drivers/tty/hvc/hvc_xen.c |    7 ++++++-
>  include/xen/xen.h         |    2 ++
>  4 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 8c923af..dc68074 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -44,7 +44,7 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
>   * - one interrupt for Xen event notifications;
>   * - one memory region to map the grant_table.
>   */
> -static int __init xen_guest_init(void)
> +int __init xen_guest_init(void)
>  {
>  	int cpu;
>  	struct xen_add_to_physmap xatp;
> @@ -58,6 +58,10 @@ static int __init xen_guest_init(void)
>  	}
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
> +	/* already setup */
> +	if (shared_info_page != 0 && HYPERVISOR_shared_info ==
shared_info_page)
> +		return 0;
> +
>  	if (!shared_info_page)
>  		shared_info_page = (struct shared_info *)
>  			get_zeroed_page(GFP_KERNEL);
> @@ -88,4 +92,5 @@ static int __init xen_guest_init(void)
>  	}
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(xen_guest_init);
Why the export symbols?
>  core_initcall(xen_guest_init);
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index ff962d4..6131d43 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1567,4 +1567,12 @@ const struct hypervisor_x86 x86_hyper_xen_hvm
__refconst = {
>  	.init_platform		= xen_hvm_guest_init,
>  };
>  EXPORT_SYMBOL(x86_hyper_xen_hvm);
> +
> +int __init xen_guest_init(void)
> +{
> +	/* do nothing: rely on x86_hyper_xen_hvm for the initialization */
> +	return 0;
> +	
> +}
> +EXPORT_SYMBOL_GPL(xen_guest_init);
>  #endif
> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> index dc07f56..3c04fb8 100644
> --- a/drivers/tty/hvc/hvc_xen.c
> +++ b/drivers/tty/hvc/hvc_xen.c
> @@ -577,6 +577,12 @@ static void __exit xen_hvc_fini(void)
>  static int xen_cons_init(void)
>  {
>  	const struct hv_ops *ops;
> +	int r;
> +
> +	/* retrieve xen infos  */
> +	r = xen_guest_init();
> +	if (r < 0)
> +		return r;
>  
>  	if (!xen_domain())
>  		return 0;
> @@ -584,7 +590,6 @@ static int xen_cons_init(void)
>  	if (xen_initial_domain())
>  		ops = &dom0_hvc_ops;
>  	else {
> -		int r;
>  		ops = &domU_hvc_ops;
>  
>  		if (xen_hvm_domain())
> diff --git a/include/xen/xen.h b/include/xen/xen.h
> index 2c0d3a5..792a4d2 100644
> --- a/include/xen/xen.h
> +++ b/include/xen/xen.h
> @@ -9,8 +9,10 @@ enum xen_domain_type {
>  
>  #ifdef CONFIG_XEN
>  extern enum xen_domain_type xen_domain_type;
> +int xen_guest_init(void);
>  #else
>  #define xen_domain_type		XEN_NATIVE
> +static inline int xen_guest_init(void) { return 0; }
>  #endif
>  
>  #define xen_domain()		(xen_domain_type != XEN_NATIVE)
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:39 UTC

head link

Re: [PATCH 13/24] xen/arm: get privilege status

On Fri, Jul 27, 2012 at 03:33:50PM +0100, Ian Campbell
wrote:> On Fri, 2012-07-27 at 15:25 +0100, Stefano Stabellini wrote:
> > On Fri, 27 Jul 2012, Ian Campbell wrote:
> > > On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > > > Use Xen features to figure out if we are privileged.
> > > > 
> > > > XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.
> > > > 
> > > > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > > > ---
> > > >  arch/arm/xen/enlighten.c         |    7 +++++++
> > > >  include/xen/interface/features.h |    3 +++
> > > >  2 files changed, 10 insertions(+), 0 deletions(-)
> > > > 
> > > > diff --git a/arch/arm/xen/enlighten.c
b/arch/arm/xen/enlighten.c
> > > > index dc68074..2e013cf 100644
> > > > --- a/arch/arm/xen/enlighten.c
> > > > +++ b/arch/arm/xen/enlighten.c
> > > > @@ -2,6 +2,7 @@
> > > >  #include <xen/interface/xen.h>
> > > >  #include <xen/interface/memory.h>
> > > >  #include <xen/platform_pci.h>
> > > > +#include <xen/features.h>
> > > >  #include <asm/xen/hypervisor.h>
> > > >  #include <asm/xen/hypercall.h>
> > > >  #include <linux/module.h>
> > > > @@ -58,6 +59,12 @@ int __init xen_guest_init(void)
> > > >  	}
> > > >  	xen_domain_type = XEN_HVM_DOMAIN;
> > > >  
> > > > +	xen_setup_features();
> > > > +	if (xen_feature(XENFEAT_dom0))
> > > > +		xen_start_info->flags |=
SIF_INITDOMAIN|SIF_PRIVILEGED;
> > > > +	else
> > > > +		xen_start_info->flags &=
~(SIF_INITDOMAIN|SIF_PRIVILEGED);
> > > 
> > > What happens here on platforms prior to hypervisor changeset
23735?
> > 
> > It wouldn''t work.
> > Considering that we are certainly not going to backport ARM support to
> > Xen 4.1, and that both ARM and XENFEAT_dom0 will be present in Xen
4.2,
> > do we really need to support the Xen unstable changesets between ARM
was
> > introduced and XENFEAT_dom0 appeared?
So should it just panic and say "AAAAAAH"?
> 
> Sorry, I missed the "arm" in the path.
> 
> Ian.
> 
>

Konrad Rzeszutek Wilk

2012-Aug-01 14:40 UTC

head link

Re: [PATCH 14/24] xen/arm: initialize grant_table on ARM

On Thu, Jul 26, 2012 at 04:33:56PM +0100, Stefano Stabellini
wrote:> Initialize the grant table mapping at the address specified at index 0
> in the DT under the /xen node.
Is it always index 0? If so, should it have a #define for the
other index values?
> After the grant table is initialized, call xenbus_probe (if not dom0).
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c  |   13 +++++++++++++
>  drivers/xen/grant-table.c |    2 +-
>  2 files changed, 14 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 2e013cf..854af1e 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -1,8 +1,12 @@
>  #include <xen/xen.h>
>  #include <xen/interface/xen.h>
>  #include <xen/interface/memory.h>
> +#include <xen/interface/hvm/params.h>
>  #include <xen/platform_pci.h>
>  #include <xen/features.h>
> +#include <xen/grant_table.h>
> +#include <xen/hvm.h>
> +#include <xen/xenbus.h>
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include <linux/module.h>
> @@ -51,12 +55,16 @@ int __init xen_guest_init(void)
>  	struct xen_add_to_physmap xatp;
>  	static struct shared_info *shared_info_page = 0;
>  	struct device_node *node;
> +	struct resource res;
>  
>  	node = of_find_compatible_node(NULL, NULL, "arm,xen");
>  	if (!node) {
>  		pr_info("No Xen support\n");
>  		return 0;
>  	}
> +	if (of_address_to_resource(node, 0, &res))
> +		return -EINVAL;
> +	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
>  	xen_setup_features();
> @@ -97,6 +105,11 @@ int __init xen_guest_init(void)
>  		per_cpu(xen_vcpu, cpu) >  		
&HYPERVISOR_shared_info->vcpu_info[cpu];
>  	}
> +
> +	gnttab_init();
> +	if (!xen_initial_domain())
> +		xenbus_probe(NULL);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(xen_guest_init);
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 1d0d95e..fd2137a 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -62,7 +62,7 @@
>  
>  static grant_ref_t **gnttab_list;
>  static unsigned int nr_grant_frames;
> -static unsigned int boot_max_nr_grant_frames;
> +static unsigned int boot_max_nr_grant_frames = 1;
Is this going to impact x86 version?
>  static int gnttab_free_count;
>  static grant_ref_t gnttab_free_head;
>  static DEFINE_SPINLOCK(gnttab_list_lock);
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:44 UTC

head link

Re: [PATCH 15/24] xen/arm: receive Xen events on ARM

On Thu, Jul 26, 2012 at 04:33:57PM +0100, Stefano Stabellini
wrote:> Compile events.c on ARM.
> Parse, map and enable the IRQ to get event notifications from the device
> tree (node "/xen").
> 
> On ARM Linux irqs are not enabled by default:
> 
> - call enable_percpu_irq for xen_events_irq (drivers are supposed
> to call enable_irq after request_irq);
> 
> - reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by
> default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn''t call
> irq_startup, that is responsible for calling irq_unmask at startup time.
> As a result event channels remain masked.
> 
> Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> ---
>  arch/arm/xen/enlighten.c |   33 +++++++++++++++++++++++++++++++++
>  arch/x86/xen/enlighten.c |    1 +
>  arch/x86/xen/irq.c       |    1 +
>  arch/x86/xen/xen-ops.h   |    1 -
>  drivers/xen/events.c     |   18 +++++++++++++++---
>  include/xen/events.h     |    2 ++
>  6 files changed, 52 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 854af1e..60d6d36 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -7,8 +7,11 @@
>  #include <xen/grant_table.h>
>  #include <xen/hvm.h>
>  #include <xen/xenbus.h>
> +#include <xen/events.h>
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqreturn.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_irq.h>
> @@ -33,6 +36,8 @@ EXPORT_SYMBOL_GPL(xen_have_vector_callback);
>  int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
>  EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
>  
> +static __read_mostly int xen_events_irq = -1;
> +
>  int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
>  			       unsigned long addr,
>  			       unsigned long mfn, int nr,
> @@ -65,6 +70,9 @@ int __init xen_guest_init(void)
>  	if (of_address_to_resource(node, 0, &res))
>  		return -EINVAL;
>  	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
> +	xen_events_irq = irq_of_parse_and_map(node, 0);
> +	pr_info("Xen support found, events_irq=%d
gnttab_frame_pfn=%lx\n",
> +			xen_events_irq, xen_hvm_resume_frames);
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
>  	xen_setup_features();
> @@ -114,3 +122,28 @@ int __init xen_guest_init(void)
>  }
>  EXPORT_SYMBOL_GPL(xen_guest_init);
>  core_initcall(xen_guest_init);
> +
> +static irqreturn_t xen_arm_callback(int irq, void *arg)
> +{
> +	xen_hvm_evtchn_do_upcall();
> +	return 0;
Um, IRQ_HANDLED?
> +}
> +
> +static int __init xen_init_events(void)
> +{
> +	if (!xen_domain() || xen_events_irq < 0)
> +		return -ENODEV;
> +
> +	xen_init_IRQ();
> +
> +	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
> +			"events", xen_vcpu)) {
> +		pr_err("Error requesting IRQ %d\n", xen_events_irq);
> +		return -EINVAL;
> +	}
> +
> +	enable_percpu_irq(xen_events_irq, 0);
> +
> +	return 0;
> +}
> +postcore_initcall(xen_init_events);
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 6131d43..5a30502 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -33,6 +33,7 @@
>  #include <linux/memblock.h>
>  
>  #include <xen/xen.h>
> +#include <xen/events.h>
>  #include <xen/interface/xen.h>
>  #include <xen/interface/version.h>
>  #include <xen/interface/physdev.h>
> diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
> index 1573376..01a4dc0 100644
> --- a/arch/x86/xen/irq.c
> +++ b/arch/x86/xen/irq.c
> @@ -5,6 +5,7 @@
>  #include <xen/interface/xen.h>
>  #include <xen/interface/sched.h>
>  #include <xen/interface/vcpu.h>
> +#include <xen/events.h>
>  
>  #include <asm/xen/hypercall.h>
>  #include <asm/xen/hypervisor.h>
> diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
> index 202d4c1..2368295 100644
> --- a/arch/x86/xen/xen-ops.h
> +++ b/arch/x86/xen/xen-ops.h
> @@ -35,7 +35,6 @@ void xen_set_pat(u64);
>  
>  char * __init xen_memory_setup(void);
>  void __init xen_arch_setup(void);
> -void __init xen_init_IRQ(void);
>  void xen_enable_sysenter(void);
>  void xen_enable_syscall(void);
>  void xen_vcpu_restore(void);
> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> index 7da65d3..9b506b2 100644
> --- a/drivers/xen/events.c
> +++ b/drivers/xen/events.c
> @@ -31,14 +31,16 @@
>  #include <linux/irqnr.h>
>  #include <linux/pci.h>
>  
> +#ifdef CONFIG_X86
>  #include <asm/desc.h>
>  #include <asm/ptrace.h>
>  #include <asm/irq.h>
>  #include <asm/idle.h>
>  #include <asm/io_apic.h>
> -#include <asm/sync_bitops.h>
>  #include <asm/xen/page.h>
>  #include <asm/xen/pci.h>
> +#endif
> +#include <asm/sync_bitops.h>
>  #include <asm/xen/hypercall.h>
>  #include <asm/xen/hypervisor.h>
>  
> @@ -50,6 +52,9 @@
>  #include <xen/interface/event_channel.h>
>  #include <xen/interface/hvm/hvm_op.h>
>  #include <xen/interface/hvm/params.h>
> +#include <xen/interface/physdev.h>
> +#include <xen/interface/sched.h>
> +#include <asm/hw_irq.h>
>  
>  /*
>   * This lock protects updates to the following mapping and reference-count
> @@ -834,6 +839,7 @@ int bind_evtchn_to_irq(unsigned int evtchn)
>  		struct irq_info *info = info_for_irq(irq);
>  		WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
>  	}
> +	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
I feel that this should be its own commit by itself. I am not certain
of the implication of this on x86 and I think it deserves some explanation.

>  
>  out:
>  	mutex_unlock(&irq_mapping_update_lock);
> @@ -1377,7 +1383,9 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
>  {
>  	struct pt_regs *old_regs = set_irq_regs(regs);
>  
> +#ifdef CONFIG_X86
>  	exit_idle();
> +#endif
Doesn''t exist? Or is that it does not need it?
>  	irq_enter();
>  
>  	__xen_evtchn_do_upcall();
> @@ -1786,9 +1794,9 @@ void xen_callback_vector(void)
>  void xen_callback_vector(void) {}
>  #endif
>  
> -void __init xen_init_IRQ(void)
> +void xen_init_IRQ(void)
>  {
> -	int i, rc;
> +	int i;
>  
>  	evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
>  				    GFP_KERNEL);
> @@ -1804,6 +1812,7 @@ void __init xen_init_IRQ(void)
>  
>  	pirq_needs_eoi = pirq_needs_eoi_flag;
>  
> +#ifdef CONFIG_X86
>  	if (xen_hvm_domain()) {
>  		xen_callback_vector();
>  		native_init_IRQ();
> @@ -1811,6 +1820,7 @@ void __init xen_init_IRQ(void)
>  		 * __acpi_register_gsi can point at the right function */
>  		pci_xen_hvm_init();
>  	} else {
> +		int rc;
>  		struct physdev_pirq_eoi_gmfn eoi_gmfn;
>  
>  		irq_ctx_init(smp_processor_id());
> @@ -1826,4 +1836,6 @@ void __init xen_init_IRQ(void)
>  		} else
>  			pirq_needs_eoi = pirq_check_eoi_map;
>  	}
> +#endif
>  }
> +EXPORT_SYMBOL_GPL(xen_init_IRQ);
> diff --git a/include/xen/events.h b/include/xen/events.h
> index 04399b2..c6bfe01 100644
> --- a/include/xen/events.h
> +++ b/include/xen/events.h
> @@ -109,4 +109,6 @@ int xen_irq_from_gsi(unsigned gsi);
>  /* Determine whether to ignore this IRQ if it is passed to a guest. */
>  int xen_test_irq_shared(int irq);
>  
> +/* initialize Xen IRQ subsystem */
> +void xen_init_IRQ(void);
>  #endif	/* _XEN_EVENTS_H */
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:47 UTC

head link

Re: [Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

On Fri, Jul 27, 2012 at 03:10:13PM +0100, Stefano Stabellini
wrote:> On Fri, 27 Jul 2012, Jan Beulich wrote:
> > >>> On 26.07.12 at 17:33, Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org> wrote:
> > > In order for privcmd mmap to work correctly,
xen_remap_domain_mfn_range
> > > needs to be implemented for HVM guests.
> > > If it is not, mmap is going to fail later on.
> > 
> > Somehow, for me at least, this description doesn''t connect to
the
> > actual change.
> 
> We can remove the "return -ENOSYS" from privcmd_mmap but the
actual mmap
> is still not going to work unless xen_remap_domain_mfn_range is
> implemented correctly.
> The x86 implementation of xen_remap_domain_mfn_range is PV only so it is
> not going to work for HVM or auto_translated_physmap guests.
> As a result mmap_batch_fn is going to fail.
So what you are saying is that this check is redundant and that earlier
on in the call stack this check is made?

I am not seeing it? I am seeing an:

289         if (!xen_initial_domain())
290                 return -EPERM;

But that would still work.

Perhaps adding an:

	if (xen_hvm_domain())
		return -ENOSYS

is more appropiate in privcmd_ioctl_mmap_batch?

Irrespective of HVM guests, I recall that it is possible to run PV guests
with XENFEAT_auto_translated_physmap? How will this be impacted?
> 
> 
> > > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > > ---
> > >  drivers/xen/privcmd.c |    4 ----
> > >  1 files changed, 0 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> > > index ccee0f1..85226cb 100644
> > > --- a/drivers/xen/privcmd.c
> > > +++ b/drivers/xen/privcmd.c
> > > @@ -380,10 +380,6 @@ static struct vm_operations_struct
privcmd_vm_ops = {
> > >  
> > >  static int privcmd_mmap(struct file *file, struct vm_area_struct
*vma)
> > >  {
> > > -	/* Unsupported for auto-translate guests. */
> > > -	if (xen_feature(XENFEAT_auto_translated_physmap))
> > > -		return -ENOSYS;
> > > -
> > 
> > Is this safe on x86?
> > 
> 
> It is safe in the sense that is not going to crash dom0 or the
> hypervisor, but it is not going to work.
> 
> Actually in order for it to be safe we need this additional change:
> 
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index 3a73785..885a223 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -2310,6 +2310,9 @@ int xen_remap_domain_mfn_range(struct vm_area_struct
*vma,
>  	unsigned long range;
>  	int err = 0;
>  
> +	if (xen_feature(XENFEAT_auto_translated_physmap))
> +		return -EINVAL;
> +
>  	prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP);
>  
>  	BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_RESERVED | VM_IO)) =>
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel-GuqFBffKawuEi8DpZVb4nw@public.gmane.org
> http://lists.xen.org/xen-devel

Konrad Rzeszutek Wilk

2012-Aug-01 14:48 UTC

head link

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

On Thu, Jul 26, 2012 at 04:34:00PM +0100, Stefano Stabellini
wrote:> Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> ---
>  drivers/block/xen-blkback/blkback.c  |    1 +
>  include/xen/interface/io/protocols.h |    3 +++
>  2 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/block/xen-blkback/blkback.c
b/drivers/block/xen-blkback/blkback.c
> index 73f196c..63dd5b9 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -42,6 +42,7 @@
>  
>  #include <xen/events.h>
>  #include <xen/page.h>
> +#include <xen/xen.h>
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include "common.h"
> diff --git a/include/xen/interface/io/protocols.h
b/include/xen/interface/io/protocols.h
> index 01fc8ae..0eafaf2 100644
> --- a/include/xen/interface/io/protocols.h
> +++ b/include/xen/interface/io/protocols.h
> @@ -5,6 +5,7 @@
>  #define XEN_IO_PROTO_ABI_X86_64     "x86_64-abi"
>  #define XEN_IO_PROTO_ABI_IA64       "ia64-abi"
>  #define XEN_IO_PROTO_ABI_POWERPC64  "powerpc64-abi"
> +#define XEN_IO_PROTO_ABI_ARM        "arm-abi"
So one that has all of the 32/64 issues worked out? Nice.
>  
>  #if defined(__i386__)
>  # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_32
> @@ -14,6 +15,8 @@
>  # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_IA64
>  #elif defined(__powerpc64__)
>  # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_POWERPC64
> +#elif defined(__arm__)
> +# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_ARM
>  #else
>  # error arch fixup needed here
>  #endif
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:52 UTC

head link

Re: [PATCH 20/24] xen: update xen_add_to_physmap interface

On Thu, Jul 26, 2012 at 04:34:02PM +0100, Stefano Stabellini
wrote:> Update struct xen_add_to_physmap to be in sync with Xen''s version
of the
> structure.
> The size field was introduced by:
> 
> changeset:   24164:707d27fe03e7
> user:        Jean Guyader <jean.guyader@eu.citrix.com>
> date:        Fri Nov 18 13:42:08 2011 +0000
> summary:     mm: New XENMEM space, XENMAPSPACE_gmfn_range
> 
> According to the comment:
> 
> "This new field .size is located in the 16 bits padding between .domid
> and .space in struct xen_add_to_physmap to stay compatible with older
> versions."
> 
> This is not true on ARM where there is not padding, but it is valid on
> X86, so introducing size is safe on X86 and it is going to fix the
> interace for ARM.
Has this been checked actually for backwards compatibility? It sounds
like it should work just fine with Xen 4.0 right?

I believe this also helps Mukesh''s patches, so CC-ing him here for
his Ack.

I can put this in right now in tree if we are 100% sure its compatiblie with
4.0.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  include/xen/interface/memory.h |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/include/xen/interface/memory.h
b/include/xen/interface/memory.h
> index abbbff0..d8e33a9 100644
> --- a/include/xen/interface/memory.h
> +++ b/include/xen/interface/memory.h
> @@ -163,6 +163,9 @@ struct xen_add_to_physmap {
>      /* Which domain to change the mapping for. */
>      domid_t domid;
>  
> +    /* Number of pages to go through for gmfn_range */
> +    uint16_t    size;
> +
>      /* Source mapping space. */
>  #define XENMAPSPACE_shared_info 0 /* shared info page */
>  #define XENMAPSPACE_grant_table 1 /* grant table page */
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:52 UTC

head link

Re: [PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present

On Thu, Jul 26, 2012 at 04:34:03PM +0100, Stefano Stabellini
wrote:> Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
Should the maintainer of the v2m be CC-ed here?
This looks like a bug-fix of itself?
> ---
>  arch/arm/mach-vexpress/v2m.c |   11 ++++++-----
>  1 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
> index fde26ad..dee1451 100644
> --- a/arch/arm/mach-vexpress/v2m.c
> +++ b/arch/arm/mach-vexpress/v2m.c
> @@ -637,16 +637,17 @@ static void __init v2m_dt_timer_init(void)
>  	node = of_find_compatible_node(NULL, NULL, "arm,sp810");
>  	v2m_sysctl_init(of_iomap(node, 0));
>  
> -	err = of_property_read_string(of_aliases, "arm,v2m_timer",
&path);
> -	if (WARN_ON(err))
> -		return;
> -	node = of_find_node_by_path(path);
> -	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
>  	if (arch_timer_of_register() != 0)
>  		twd_local_timer_of_register();
>  
>  	if (arch_timer_sched_clock_init() != 0)
>  		versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ, 24000000);
> +
> +	err = of_property_read_string(of_aliases, "arm,v2m_timer",
&path);
> +	if (WARN_ON(err))
> +		return;
> +	node = of_find_node_by_path(path);
> +	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
>  }
>  
>  static struct sys_timer v2m_dt_timer = {
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:54 UTC

head link

Re: [PATCH 23/24] hvc_xen: allow dom0_write_console for HVM guests

On Thu, Jul 26, 2012 at 04:34:05PM +0100, Stefano Stabellini
wrote:> On ARM all guests are HVM guests, including Dom0.
> Allow dom0_write_console to be called by an HVM domain.
Um, but xen_hvm_domain() != xen_pv_domain() so won''t this return
without
printing anything?
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  drivers/tty/hvc/hvc_xen.c |    5 +----
>  1 files changed, 1 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> index 3c04fb8..949edc2 100644
> --- a/drivers/tty/hvc/hvc_xen.c
> +++ b/drivers/tty/hvc/hvc_xen.c
> @@ -616,12 +616,9 @@ static void xenboot_write_console(struct console
*console, const char *string,
>  	unsigned int linelen, off = 0;
>  	const char *pos;
>  
> -	if (!xen_pv_domain())
> -		return;
> -
>  	dom0_write_console(0, string, len);
>  
> -	if (xen_initial_domain())
> +	if (!xen_pv_domain())
>  		return;
>  
>  	domU_write_console(0, "(early) ", 8);
> -- 
> 1.7.2.5

Konrad Rzeszutek Wilk

2012-Aug-01 14:56 UTC

head link

Re: [PATCH 24/24] [HACK] xen/arm: implement xen_remap_domain_mfn_range

On Thu, Jul 26, 2012 at 04:34:06PM +0100, Stefano Stabellini
wrote:> From: Ian Campbell
<Ian.Campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>
> 
> Do not apply!
Mukesh, I believe this is similar to what you had in mind.
> 
> This is a simple, hacky implementation of xen_remap_domain_mfn_range,
> using XENMAPSPACE_gmfn_foreign.
> 
> It should use same interface as hybrid x86.
Yeah.. We should get this done irrespective of this ARM patchset as
it will certainly benefit the HVM domains.

So  what is with the 0x9000 values?
> 
> Signed-off-by: Ian Campbell
<Ian.Campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> ---
>  arch/arm/xen/enlighten.c       |   79
+++++++++++++++++++++++++++++++++++++++-
>  drivers/xen/privcmd.c          |   16 +++++----
>  drivers/xen/xenfs/super.c      |    7 ++++
>  include/xen/interface/memory.h |   10 ++++--
>  4 files changed, 101 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 1476b0b..7092015 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -16,6 +16,10 @@
>  #include <linux/of.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_address.h>
> +#include <linux/mm.h>
> +#include <linux/ioport.h>
> +
> +#include <asm/pgtable.h>
>  
>  struct start_info _xen_start_info;
>  struct start_info *xen_start_info = &_xen_start_info;
> @@ -38,12 +42,85 @@ EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
>  
>  static __read_mostly int xen_events_irq = -1;
>  
> +#define FOREIGN_MAP_BUFFER 0x90000000UL
> +#define FOREIGN_MAP_BUFFER_SIZE 0x10000000UL
> +struct resource foreign_map_resource = {
> +	.start = FOREIGN_MAP_BUFFER,
> +	.end = FOREIGN_MAP_BUFFER + FOREIGN_MAP_BUFFER_SIZE,
> +	.name = "Xen foreign map buffer",
> +	.flags = 0,
> +};
> +
> +static unsigned long foreign_map_buffer_pfn = FOREIGN_MAP_BUFFER >>
PAGE_SHIFT;
> +
> +struct remap_data {
> +	struct mm_struct *mm;
> +	unsigned long mfn;
> +	pgprot_t prot;
> +};
> +
> +static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
> +				 unsigned long addr, void *data)
> +{
> +	struct remap_data *rmd = data;
> +	pte_t pte = pfn_pte(rmd->mfn, rmd->prot);
> +
> +	if (rmd->mfn < 0x90010)
> +		pr_crit("%s: ptep %p addr %#lx => %#x / %#lx\n",
> +		       __func__, ptep, addr, pte_val(pte), rmd->mfn);
> +
> +	set_pte_at(rmd->mm, addr, ptep, pte);
> +
> +	rmd->mfn++;
> +	return 0;
> +}
> +
>  int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
>  			       unsigned long addr,
>  			       unsigned long mfn, int nr,
>  			       pgprot_t prot, unsigned domid)
>  {
> -	return -ENOSYS;
> +	int i, rc = 0;
> +	struct remap_data rmd = {
> +		.mm = vma->vm_mm,
> +		.prot = prot,
> +	};
> +	struct xen_add_to_physmap xatp = {
> +		.domid = DOMID_SELF,
> +		.space = XENMAPSPACE_gmfn_foreign,
> +
> +		.foreign_domid = domid,
> +	};
> +
> +	if (foreign_map_buffer_pfn + nr > ((FOREIGN_MAP_BUFFER +
> +					FOREIGN_MAP_BUFFER_SIZE)>>PAGE_SHIFT)) {
> +		pr_crit("RAM out of foreign map buffers...\n");
> +		return -EBUSY;
> +	}
> +
> +	for (i = 0; i < nr; i++) {
> +		xatp.idx = mfn + i;
> +		xatp.gpfn = foreign_map_buffer_pfn + i;
> +		rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
> +		if (rc != 0) {
> +			pr_crit("foreign map add_to_physmap failed, err=%d\n", rc);
> +			goto out;
> +		}
> +	}
> +
> +	rmd.mfn = foreign_map_buffer_pfn;
> +	rc = apply_to_page_range(vma->vm_mm,
> +				 addr,
> +				 (unsigned long)nr << PAGE_SHIFT,
> +				 remap_area_mfn_pte_fn, &rmd);
> +	if (rc != 0) {
> +		pr_crit("apply_to_page_range failed rc=%d\n", rc);
> +		goto out;
> +	}
> +
> +	foreign_map_buffer_pfn += nr;
> +out:
> +	return rc;
>  }
>  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
>  
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> index 85226cb..3e15c22 100644
> --- a/drivers/xen/privcmd.c
> +++ b/drivers/xen/privcmd.c
> @@ -20,6 +20,8 @@
>  #include <linux/pagemap.h>
>  #include <linux/seq_file.h>
>  #include <linux/miscdevice.h>
> +#include <linux/resource.h>
> +#include <linux/ioport.h>
>  
>  #include <asm/pgalloc.h>
>  #include <asm/pgtable.h>
> @@ -196,9 +198,6 @@ static long privcmd_ioctl_mmap(void __user *udata)
>  	LIST_HEAD(pagelist);
>  	struct mmap_mfn_state state;
>  
> -	if (!xen_initial_domain())
> -		return -EPERM;
> -
>  	if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
>  		return -EFAULT;
>  
> @@ -286,9 +285,6 @@ static long privcmd_ioctl_mmap_batch(void __user
*udata)
>  	LIST_HEAD(pagelist);
>  	struct mmap_batch_state state;
>  
> -	if (!xen_initial_domain())
> -		return -EPERM;
> -
>  	if (copy_from_user(&m, udata, sizeof(m)))
>  		return -EFAULT;
>  
> @@ -365,6 +361,11 @@ static long privcmd_ioctl(struct file *file,
>  	return ret;
>  }
>  
> +static void privcmd_close(struct vm_area_struct *vma)
> +{
> +	/* TODO: unmap VMA */
> +}
> +
>  static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
>  	printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx,
uv=%p\n",
> @@ -375,7 +376,8 @@ static int privcmd_fault(struct vm_area_struct *vma,
struct vm_fault *vmf)
>  }
>  
>  static struct vm_operations_struct privcmd_vm_ops = {
> -	.fault = privcmd_fault
> +	.fault = privcmd_fault,
> +	.close = privcmd_close,
>  };
>  
>  static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
> diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
> index a84b53c..edbe22f 100644
> --- a/drivers/xen/xenfs/super.c
> +++ b/drivers/xen/xenfs/super.c
> @@ -12,6 +12,7 @@
>  #include <linux/module.h>
>  #include <linux/fs.h>
>  #include <linux/magic.h>
> +#include <linux/ioport.h>
>  
>  #include <xen/xen.h>
>  
> @@ -80,6 +81,8 @@ static const struct file_operations capabilities_file_ops
= {
>  	.llseek = default_llseek,
>  };
>  
> +extern struct resource foreign_map_resource;
> +
>  static int xenfs_fill_super(struct super_block *sb, void *data, int
silent)
>  {
>  	static struct tree_descr xenfs_files[] = {
> @@ -100,6 +103,10 @@ static int xenfs_fill_super(struct super_block *sb,
void *data, int silent)
>  				  &xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR);
>  		xenfs_create_file(sb, sb->s_root, "xsd_port",
>  				  &xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR);
> +		rc = request_resource(&iomem_resource, &foreign_map_resource);
> +		if (rc < 0)
> +			pr_crit("failed to register foreign map resource\n");
> +		rc = 0; /* ignore */
>  	}
>  
>  	return rc;
> diff --git a/include/xen/interface/memory.h
b/include/xen/interface/memory.h
> index d8e33a9..ec68945 100644
> --- a/include/xen/interface/memory.h
> +++ b/include/xen/interface/memory.h
> @@ -167,9 +167,13 @@ struct xen_add_to_physmap {
>      uint16_t    size;
>  
>      /* Source mapping space. */
> -#define XENMAPSPACE_shared_info 0 /* shared info page */
> -#define XENMAPSPACE_grant_table 1 /* grant table page */
> -    unsigned int space;
> +#define XENMAPSPACE_shared_info  0 /* shared info page */
> +#define XENMAPSPACE_grant_table  1 /* grant table page */
> +#define XENMAPSPACE_gmfn         2 /* GMFN */
> +#define XENMAPSPACE_gmfn_range   3 /* GMFN range */
> +#define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another guest */
> +    uint16_t space;
> +    domid_t foreign_domid; /* IFF gmfn_foreign */
>  
>      /* Index into source mapping space. */
>      unsigned long idx;
> -- 
> 1.7.2.5

Stefano Stabellini

2012-Aug-01 15:45 UTC

head link

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:49PM +0100, Stefano Stabellini wrote:
> > Check for a "/xen" node in the device tree, if it is present
set
> > xen_domain_type to XEN_HVM_DOMAIN and continue initialization.
> > 
> > Map the real shared info page using XENMEM_add_to_physmap with
> > XENMAPSPACE_shared_info.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/xen/enlighten.c |   56
++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 56 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index d27c2a6..8c923af 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -5,6 +5,9 @@
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> >  #include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/of_address.h>
> >  
> >  struct start_info _xen_start_info;
> >  struct start_info *xen_start_info = &_xen_start_info;
> > @@ -33,3 +36,56 @@ int xen_remap_domain_mfn_range(struct
vm_area_struct *vma,
> >  	return -ENOSYS;
> >  }
> >  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> > +
> > +/*
> > + * == Xen Device Tree format => > + * - /xen node;
> > + * - compatible "arm,xen";
> > + * - one interrupt for Xen event notifications;
> > + * - one memory region to map the grant_table.
> > + */
> > +static int __init xen_guest_init(void)
> > +{
> > +	int cpu;
> > +	struct xen_add_to_physmap xatp;
> > +	static struct shared_info *shared_info_page = 0;
> > +	struct device_node *node;
> > +
> > +	node = of_find_compatible_node(NULL, NULL, "arm,xen");
> > +	if (!node) {
> > +		pr_info("No Xen support\n");
> 
> I don''t think the pr_info is appropiate here?
Yes, you are right. In fact I had already turned it into a pr_debug.
> > +		return 0;
> 
> Should this be -ENODEV?
Considering that xen_guest_init is called by a core_initcall, I didn''t
want to return an error just because Xen is not present on the platform.

> > +	}
> > +	xen_domain_type = XEN_HVM_DOMAIN;
> > +
> > +	if (!shared_info_page)
> > +		shared_info_page = (struct shared_info *)
> > +			get_zeroed_page(GFP_KERNEL);
> > +	if (!shared_info_page) {
> > +		pr_err("not enough memory");
> 
> \n
OK
> > +		return -ENOMEM;
> > +	}
> > +	xatp.domid = DOMID_SELF;
> > +	xatp.idx = 0;
> > +	xatp.space = XENMAPSPACE_shared_info;
> > +	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> > +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> > +		BUG();
> > +
> > +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> > +
> > +	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
> > +	 * page, we use it in the event channel upcall and in some pvclock
> > +	 * related functions. We don''t need the vcpu_info placement
> > +	 * optimizations because we don''t use any pv_mmu or pv_irq
op on
> > +	 * HVM.
> > +	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
> > +	 * online but xen_hvm_init_shared_info is run at resume time too and
> > +	 * in that case multiple vcpus might be online. */
> > +	for_each_online_cpu(cpu) {
> > +		per_cpu(xen_vcpu, cpu) > > +		
&HYPERVISOR_shared_info->vcpu_info[cpu];
> > +	}
> > +	return 0;
> 
> This above looks stringly similar to the x86 one. Could it be
> abstracted away to share the same code? Or is that something that
> ought to be done later on when there is more meat on the bone?
Actually I had to remove these three lines because on ARM we are going
to have just one vcpu_info struct in the shared_info page and then rely
on VCPUOP_register_vcpu_info.

Stefano Stabellini

2012-Aug-01 15:46 UTC

head link

Re: [PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:47PM +0100, Stefano Stabellini wrote:
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > ---
> >  arch/arm/xen/Makefile      |    2 +-
> >  arch/arm/xen/grant-table.c |   53
++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 54 insertions(+), 1 deletions(-)
> >  create mode 100644 arch/arm/xen/grant-table.c
> > 
> > diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> > index b9d6acc..4384103 100644
> > --- a/arch/arm/xen/Makefile
> > +++ b/arch/arm/xen/Makefile
> > @@ -1 +1 @@
> > -obj-y		:= enlighten.o hypercall.o
> > +obj-y		:= enlighten.o hypercall.o grant-table.o
> > diff --git a/arch/arm/xen/grant-table.c b/arch/arm/xen/grant-table.c
> > new file mode 100644
> > index 0000000..0a4ee80
> > --- /dev/null
> > +++ b/arch/arm/xen/grant-table.c
> > @@ -0,0 +1,53 @@
> >
+/******************************************************************************
> > + * grant_table.c
> > + * ARM specific part
> > + *
> > + * Granting foreign access to our memory reservation.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
version 2
> > + * as published by the Free Software Foundation; or, when distributed
> > + * separately from the Linux kernel or incorporated into other
> > + * software packages, subject to the following license:
> > + *
> > + * Permission is hereby granted, free of charge, to any person
obtaining a copy
> > + * of this source file (the "Software"), to deal in the
Software without
> > + * restriction, including without limitation the rights to use, copy,
modify,
> > + * merge, publish, distribute, sublicense, and/or sell copies of the
Software,
> > + * and to permit persons to whom the Software is furnished to do so,
subject to
> > + * the following conditions:
> > + *
> > + * The above copyright notice and this permission notice shall be
included in
> > + * all copies or substantial portions of the Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
SHALL THE
> > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING
> > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS
> > + * IN THE SOFTWARE.
> > + */
> > +
> > +#include <xen/interface/xen.h>
> > +#include <xen/page.h>
> > +#include <xen/grant_table.h>
> > +
> > +int arch_gnttab_map_shared(unsigned long *frames, unsigned long
nr_gframes,
> > +			   unsigned long max_nr_gframes,
> > +			   void **__shared)
> > +{
> > +	return -1;
> 
> -ENOSYS
> > +}
> > +
> > +void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
> > +{
> > +	return;
> > +}
> > +
> > +int arch_gnttab_map_status(uint64_t *frames, unsigned long
nr_gframes,
> > +			   unsigned long max_nr_gframes,
> > +			   grant_status_t **__shared)
> > +{
> > +	return -1;
> 
> Same here -ENOSYS
OK, I''ll do that

Stefano Stabellini

2012-Aug-01 15:50 UTC

head link

Re: [PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:50PM +0100, Stefano Stabellini wrote:
> > All the original Xen headers have xen_pfn_t as mfn and pfn type,
however
> > when they have been imported in Linux, xen_pfn_t has been replaced
with
> > unsigned long. That might work for x86 and ia64 but it does not for
arm.
> 
> How come?
see below
> > Bring back xen_pfn_t and let each architecture define xen_pfn_t as
they
> > see fit.
> 
> I am OK with this as long as your include a comment in both of the
> interface.h saying why this is needed. I am curious why ''unsinged
long''
> won''t work? Is it b/c on ARM you always want a 64-bit type?
Yes, we would like to make the same interface work for 32 and 64
bit guests, without any need for a "compat layer" as we currently have
on x86.
In fact I am going to add another patch to explicitly size all the
other unsigned long that we have in the public interface.

Stefano Stabellini

2012-Aug-01 16:04 UTC

head link

Re: [PATCH 23/24] hvc_xen: allow dom0_write_console for HVM guests

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:34:05PM +0100, Stefano Stabellini wrote:
> > On ARM all guests are HVM guests, including Dom0.
> > Allow dom0_write_console to be called by an HVM domain.
> 
> Um, but xen_hvm_domain() != xen_pv_domain() so won''t this return
without
> printing anything?
Nope, it would call dom0_write_console that issues a console hypercall.
However I am going to remove this patch and rely on the simple serial
emulator we have in Xen for early_printk stuff
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > ---
> >  drivers/tty/hvc/hvc_xen.c |    5 +----
> >  1 files changed, 1 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> > index 3c04fb8..949edc2 100644
> > --- a/drivers/tty/hvc/hvc_xen.c
> > +++ b/drivers/tty/hvc/hvc_xen.c
> > @@ -616,12 +616,9 @@ static void xenboot_write_console(struct console
*console, const char *string,
> >  	unsigned int linelen, off = 0;
> >  	const char *pos;
> >  
> > -	if (!xen_pv_domain())
> > -		return;
> > -
> >  	dom0_write_console(0, string, len);
> >  
> > -	if (xen_initial_domain())
> > +	if (!xen_pv_domain())
> >  		return;
> >  
> >  	domU_write_console(0, "(early) ", 8);
> > -- 
> > 1.7.2.5
>

Stefano Stabellini

2012-Aug-01 16:06 UTC

head link

Re: [PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:34:03PM +0100, Stefano Stabellini wrote:
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> 
> Should the maintainer of the v2m be CC-ed here?
> This looks like a bug-fix of itself?
I think so. I''ll CC Russell King next time.
> > ---
> >  arch/arm/mach-vexpress/v2m.c |   11 ++++++-----
> >  1 files changed, 6 insertions(+), 5 deletions(-)
> > 
> > diff --git a/arch/arm/mach-vexpress/v2m.c
b/arch/arm/mach-vexpress/v2m.c
> > index fde26ad..dee1451 100644
> > --- a/arch/arm/mach-vexpress/v2m.c
> > +++ b/arch/arm/mach-vexpress/v2m.c
> > @@ -637,16 +637,17 @@ static void __init v2m_dt_timer_init(void)
> >  	node = of_find_compatible_node(NULL, NULL, "arm,sp810");
> >  	v2m_sysctl_init(of_iomap(node, 0));
> >  
> > -	err = of_property_read_string(of_aliases, "arm,v2m_timer",
&path);
> > -	if (WARN_ON(err))
> > -		return;
> > -	node = of_find_node_by_path(path);
> > -	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
> >  	if (arch_timer_of_register() != 0)
> >  		twd_local_timer_of_register();
> >  
> >  	if (arch_timer_sched_clock_init() != 0)
> >  		versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ,
24000000);
> > +
> > +	err = of_property_read_string(of_aliases, "arm,v2m_timer",
&path);
> > +	if (WARN_ON(err))
> > +		return;
> > +	node = of_find_node_by_path(path);
> > +	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
> >  }
> >  
> >  static struct sys_timer v2m_dt_timer = {
> > -- 
> > 1.7.2.5
>

Stefano Stabellini

2012-Aug-01 16:07 UTC

head link

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Fri, Jul 27, 2012 at 10:28:25AM +0100, Ian Campbell wrote:
> > On Thu, 2012-07-26 at 17:37 +0100, Konrad Rzeszutek Wilk wrote:
> > > On Thu, Jul 26, 2012 at 04:33:46PM +0100, Stefano Stabellini
wrote:
> > > > sync_bitops functions are equivalent to the SMP
implementation of the
> > > > original functions, independently from CONFIG_SMP being
defined.
> > > 
> > > So why can''t the code be changed to use that? Is it that
> > > the _set_bit, _clear_bit, etc are not available with !CONFIG_SMP?
> > 
> > _set_bit etc are not SMP safe if !CONFIG_SMP. But under Xen you might
be
> > communicating with a completely external entity who might be on
another
> > CPU (e.g. two uniprocessor guests communicating via event channels and
> > grant tables). So we need a variant of the bit ops which are SMP safe
> > even on a UP kernel.
> > 
> > The users are common code and the sync_foo vs foo distinction matters
on
> > some platforms (e.g. x86 where a UP kernel would omit the LOCK prefix
> > for the normal ones).
> 
> OK, that makes sense. Stefano can you include that comment in the git
> commit description and in the sync_bitops.h file please?
Yep, I''ll do that.

Stefano Stabellini

2012-Aug-01 16:18 UTC

head link

Re: [PATCH 20/24] xen: update xen_add_to_physmap interface

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:34:02PM +0100, Stefano Stabellini wrote:
> > Update struct xen_add_to_physmap to be in sync with Xen''s
version of the
> > structure.
> > The size field was introduced by:
> > 
> > changeset:   24164:707d27fe03e7
> > user:        Jean Guyader <jean.guyader@eu.citrix.com>
> > date:        Fri Nov 18 13:42:08 2011 +0000
> > summary:     mm: New XENMEM space, XENMAPSPACE_gmfn_range
> > 
> > According to the comment:
> > 
> > "This new field .size is located in the 16 bits padding between
.domid
> > and .space in struct xen_add_to_physmap to stay compatible with older
> > versions."
> > 
> > This is not true on ARM where there is not padding, but it is valid on
> > X86, so introducing size is safe on X86 and it is going to fix the
> > interace for ARM.
> 
> Has this been checked actually for backwards compatibility? It sounds
> like it should work just fine with Xen 4.0 right?
> 
> I believe this also helps Mukesh''s patches, so CC-ing him here for
> his Ack.
> 
> I can put this in right now in tree if we are 100% sure its compatiblie
with 4.0.
Yes, it is: 4 bytes integers are 4-byte aligned on 32 bit and 64 bit
on x86.

Stefano Stabellini

2012-Aug-01 16:19 UTC

head link

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:34:00PM +0100, Stefano Stabellini wrote:
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  drivers/block/xen-blkback/blkback.c  |    1 +
> >  include/xen/interface/io/protocols.h |    3 +++
> >  2 files changed, 4 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/block/xen-blkback/blkback.c
b/drivers/block/xen-blkback/blkback.c
> > index 73f196c..63dd5b9 100644
> > --- a/drivers/block/xen-blkback/blkback.c
> > +++ b/drivers/block/xen-blkback/blkback.c
> > @@ -42,6 +42,7 @@
> >  
> >  #include <xen/events.h>
> >  #include <xen/page.h>
> > +#include <xen/xen.h>
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> >  #include "common.h"
> > diff --git a/include/xen/interface/io/protocols.h
b/include/xen/interface/io/protocols.h
> > index 01fc8ae..0eafaf2 100644
> > --- a/include/xen/interface/io/protocols.h
> > +++ b/include/xen/interface/io/protocols.h
> > @@ -5,6 +5,7 @@
> >  #define XEN_IO_PROTO_ABI_X86_64     "x86_64-abi"
> >  #define XEN_IO_PROTO_ABI_IA64       "ia64-abi"
> >  #define XEN_IO_PROTO_ABI_POWERPC64  "powerpc64-abi"
> > +#define XEN_IO_PROTO_ABI_ARM        "arm-abi"
> 
> So one that has all of the 32/64 issues worked out? Nice.
Yes, that is the idea, but it needs another patch to actually achieve
the goal :)
> >  
> >  #if defined(__i386__)
> >  # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_32
> > @@ -14,6 +15,8 @@
> >  # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_IA64
> >  #elif defined(__powerpc64__)
> >  # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_POWERPC64
> > +#elif defined(__arm__)
> > +# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_ARM
> >  #else
> >  # error arch fixup needed here
> >  #endif
> > -- 
> > 1.7.2.5
>

Stefano Stabellini

2012-Aug-01 16:21 UTC

head link

Re: [PATCH 13/24] xen/arm: get privilege status

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Fri, Jul 27, 2012 at 03:33:50PM +0100, Ian Campbell wrote:
> > On Fri, 2012-07-27 at 15:25 +0100, Stefano Stabellini wrote:
> > > On Fri, 27 Jul 2012, Ian Campbell wrote:
> > > > On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> > > > > Use Xen features to figure out if we are privileged.
> > > > > 
> > > > > XENFEAT_dom0 was introduced by 23735 in
xen-unstable.hg.
> > > > > 
> > > > > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > > > > ---
> > > > >  arch/arm/xen/enlighten.c         |    7 +++++++
> > > > >  include/xen/interface/features.h |    3 +++
> > > > >  2 files changed, 10 insertions(+), 0 deletions(-)
> > > > > 
> > > > > diff --git a/arch/arm/xen/enlighten.c
b/arch/arm/xen/enlighten.c
> > > > > index dc68074..2e013cf 100644
> > > > > --- a/arch/arm/xen/enlighten.c
> > > > > +++ b/arch/arm/xen/enlighten.c
> > > > > @@ -2,6 +2,7 @@
> > > > >  #include <xen/interface/xen.h>
> > > > >  #include <xen/interface/memory.h>
> > > > >  #include <xen/platform_pci.h>
> > > > > +#include <xen/features.h>
> > > > >  #include <asm/xen/hypervisor.h>
> > > > >  #include <asm/xen/hypercall.h>
> > > > >  #include <linux/module.h>
> > > > > @@ -58,6 +59,12 @@ int __init xen_guest_init(void)
> > > > >  	}
> > > > >  	xen_domain_type = XEN_HVM_DOMAIN;
> > > > >  
> > > > > +	xen_setup_features();
> > > > > +	if (xen_feature(XENFEAT_dom0))
> > > > > +		xen_start_info->flags |=
SIF_INITDOMAIN|SIF_PRIVILEGED;
> > > > > +	else
> > > > > +		xen_start_info->flags &=
~(SIF_INITDOMAIN|SIF_PRIVILEGED);
> > > > 
> > > > What happens here on platforms prior to hypervisor changeset
23735?
> > > 
> > > It wouldn''t work.
> > > Considering that we are certainly not going to backport ARM
support to
> > > Xen 4.1, and that both ARM and XENFEAT_dom0 will be present in
Xen 4.2,
> > > do we really need to support the Xen unstable changesets between
ARM was
> > > introduced and XENFEAT_dom0 appeared?
> 
> So should it just panic and say "AAAAAAH"?
I could panic if I find out that XENFEAT_dom0 is unimplemented but
actually I only get to know if it is available...

Stefano Stabellini

2012-Aug-01 17:08 UTC

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Re: [PATCH 14/24] xen/arm: initialize grant_table on ARM

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:56PM +0100, Stefano Stabellini wrote:
> > Initialize the grant table mapping at the address specified at index 0
> > in the DT under the /xen node.
> 
> Is it always index 0? If so, should it have a #define for the
> other index values?
There are no other values at the moment but I''ll add an #define.

> > After the grant table is initialized, call xenbus_probe (if not dom0).
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > ---
> >  arch/arm/xen/enlighten.c  |   13 +++++++++++++
> >  drivers/xen/grant-table.c |    2 +-
> >  2 files changed, 14 insertions(+), 1 deletions(-)
> > 
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index 2e013cf..854af1e 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -1,8 +1,12 @@
> >  #include <xen/xen.h>
> >  #include <xen/interface/xen.h>
> >  #include <xen/interface/memory.h>
> > +#include <xen/interface/hvm/params.h>
> >  #include <xen/platform_pci.h>
> >  #include <xen/features.h>
> > +#include <xen/grant_table.h>
> > +#include <xen/hvm.h>
> > +#include <xen/xenbus.h>
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> >  #include <linux/module.h>
> > @@ -51,12 +55,16 @@ int __init xen_guest_init(void)
> >  	struct xen_add_to_physmap xatp;
> >  	static struct shared_info *shared_info_page = 0;
> >  	struct device_node *node;
> > +	struct resource res;
> >  
> >  	node = of_find_compatible_node(NULL, NULL, "arm,xen");
> >  	if (!node) {
> >  		pr_info("No Xen support\n");
> >  		return 0;
> >  	}
> > +	if (of_address_to_resource(node, 0, &res))
> > +		return -EINVAL;
> > +	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
> >  	xen_domain_type = XEN_HVM_DOMAIN;
> >  
> >  	xen_setup_features();
> > @@ -97,6 +105,11 @@ int __init xen_guest_init(void)
> >  		per_cpu(xen_vcpu, cpu) > >  		
&HYPERVISOR_shared_info->vcpu_info[cpu];
> >  	}
> > +
> > +	gnttab_init();
> > +	if (!xen_initial_domain())
> > +		xenbus_probe(NULL);
> > +
> >  	return 0;
> >  }
> >  EXPORT_SYMBOL_GPL(xen_guest_init);
> > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> > index 1d0d95e..fd2137a 100644
> > --- a/drivers/xen/grant-table.c
> > +++ b/drivers/xen/grant-table.c
> > @@ -62,7 +62,7 @@
> >  
> >  static grant_ref_t **gnttab_list;
> >  static unsigned int nr_grant_frames;
> > -static unsigned int boot_max_nr_grant_frames;
> > +static unsigned int boot_max_nr_grant_frames = 1;
> 
> Is this going to impact x86 version?
It is not needed so I''ll remove this change

Mukesh Rathor

2012-Aug-01 18:19 UTC

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Re: [PATCH 20/24] xen: update xen_add_to_physmap interface

On Wed, 1 Aug 2012 10:52:15 -0400
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote:
> On Thu, Jul 26, 2012 at 04:34:02PM +0100, Stefano Stabellini wrote:
> > Update struct xen_add_to_physmap to be in sync with Xen''s
version
> > of the structure.
> > The size field was introduced by:
> > 
> > changeset:   24164:707d27fe03e7
> > user:        Jean Guyader <jean.guyader@eu.citrix.com>
> > date:        Fri Nov 18 13:42:08 2011 +0000
> > summary:     mm: New XENMEM space, XENMAPSPACE_gmfn_range
> > 
> > According to the comment:
> > 
> > "This new field .size is located in the 16 bits padding
> > between .domid and .space in struct xen_add_to_physmap to stay
> > compatible with older versions."
> > 
> > This is not true on ARM where there is not padding, but it is valid
> > on X86, so introducing size is safe on X86 and it is going to fix
> > the interace for ARM.
> 
> Has this been checked actually for backwards compatibility? It sounds
> like it should work just fine with Xen 4.0 right?
> 
> I believe this also helps Mukesh''s patches, so CC-ing him here for
> his Ack.
Yup, I already had that change in my tree.

thanks,
Mukesh

Rob Herring

2012-Aug-01 18:27 UTC

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Re: [PATCH 01/24] arm: initial Xen support

On 07/26/2012 10:33 AM, Stefano Stabellini wrote:> - Basic hypervisor.h and interface.h definitions.
> - Skelethon enlighten.c, set xen_start_info to an empty struct.
> - Do not limit xen_initial_domain to PV guests.
> 
> The new code only compiles when CONFIG_XEN is set, that is going to be
> added to arch/arm/Kconfig in a later patch.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/Makefile                     |    1 +
>  arch/arm/include/asm/hypervisor.h     |    6 +++
>  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
>  arch/arm/include/asm/xen/interface.h  |   64
+++++++++++++++++++++++++++++++++
These headers don''t seem particularly ARM specific. Could they be moved
to asm-generic or include/linux?

Rob
>  arch/arm/xen/Makefile                 |    1 +
>  arch/arm/xen/enlighten.c              |   35 ++++++++++++++++++
>  include/xen/xen.h                     |    2 +-
>  7 files changed, 127 insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/include/asm/hypervisor.h
>  create mode 100644 arch/arm/include/asm/xen/hypervisor.h
>  create mode 100644 arch/arm/include/asm/xen/interface.h
>  create mode 100644 arch/arm/xen/Makefile
>  create mode 100644 arch/arm/xen/enlighten.c
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 0298b00..70aaa82 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -246,6 +246,7 @@ endif
>  core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
>  core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
>  core-$(CONFIG_VFP)		+= arch/arm/vfp/
> +core-$(CONFIG_XEN)		+= arch/arm/xen/
>  
>  # If we have a machine-specific directory, then include it in the build.
>  core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
> diff --git a/arch/arm/include/asm/hypervisor.h
b/arch/arm/include/asm/hypervisor.h
> new file mode 100644
> index 0000000..b90d9e5
> --- /dev/null
> +++ b/arch/arm/include/asm/hypervisor.h
> @@ -0,0 +1,6 @@
> +#ifndef _ASM_ARM_HYPERVISOR_H
> +#define _ASM_ARM_HYPERVISOR_H
> +
> +#include <asm/xen/hypervisor.h>
> +
> +#endif
> diff --git a/arch/arm/include/asm/xen/hypervisor.h
b/arch/arm/include/asm/xen/hypervisor.h
> new file mode 100644
> index 0000000..d7ab99a
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/hypervisor.h
> @@ -0,0 +1,19 @@
> +#ifndef _ASM_ARM_XEN_HYPERVISOR_H
> +#define _ASM_ARM_XEN_HYPERVISOR_H
> +
> +extern struct shared_info *HYPERVISOR_shared_info;
> +extern struct start_info *xen_start_info;
> +
> +/* Lazy mode for batching updates / context switch */
> +enum paravirt_lazy_mode {
> +	PARAVIRT_LAZY_NONE,
> +	PARAVIRT_LAZY_MMU,
> +	PARAVIRT_LAZY_CPU,
> +};
> +
> +static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
> +{
> +	return PARAVIRT_LAZY_NONE;
> +}
> +
> +#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
> diff --git a/arch/arm/include/asm/xen/interface.h
b/arch/arm/include/asm/xen/interface.h
> new file mode 100644
> index 0000000..6c3ab59
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/interface.h
> @@ -0,0 +1,64 @@
>
+/******************************************************************************
> + * Guest OS interface to ARM Xen.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix,
2011
> + */
> +
> +#ifndef _ASM_ARM_XEN_INTERFACE_H
> +#define _ASM_ARM_XEN_INTERFACE_H
> +
> +#include <linux/types.h>
> +
> +#define __DEFINE_GUEST_HANDLE(name, type) \
> +	typedef type * __guest_handle_ ## name
> +
> +#define DEFINE_GUEST_HANDLE_STRUCT(name) \
> +	__DEFINE_GUEST_HANDLE(name, struct name)
> +#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
> +#define GUEST_HANDLE(name)        __guest_handle_ ## name
> +
> +#define set_xen_guest_handle(hnd, val)			\
> +	do {						\
> +		if (sizeof(hnd) == 8)			\
> +			*(uint64_t *)&(hnd) = 0;	\
> +		(hnd) = val;				\
> +	} while (0)
> +
> +#ifndef __ASSEMBLY__
> +/* Guest handles for primitive C types. */
> +__DEFINE_GUEST_HANDLE(uchar, unsigned char);
> +__DEFINE_GUEST_HANDLE(uint,  unsigned int);
> +__DEFINE_GUEST_HANDLE(ulong, unsigned long);
> +DEFINE_GUEST_HANDLE(char);
> +DEFINE_GUEST_HANDLE(int);
> +DEFINE_GUEST_HANDLE(long);
> +DEFINE_GUEST_HANDLE(void);
> +DEFINE_GUEST_HANDLE(uint64_t);
> +DEFINE_GUEST_HANDLE(uint32_t);
> +
> +/* Maximum number of virtual CPUs in multi-processor guests. */
> +#define MAX_VIRT_CPUS 1
> +
> +struct arch_vcpu_info { };
> +struct arch_shared_info { };
> +
> +/* XXX: Move pvclock definitions some place arch independent */
> +struct pvclock_vcpu_time_info {
> +	u32   version;
> +	u32   pad0;
> +	u64   tsc_timestamp;
> +	u64   system_time;
> +	u32   tsc_to_system_mul;
> +	s8    tsc_shift;
> +	u8    flags;
> +	u8    pad[2];
> +} __attribute__((__packed__)); /* 32 bytes */
> +
> +struct pvclock_wall_clock {
> +	u32   version;
> +	u32   sec;
> +	u32   nsec;
> +} __attribute__((__packed__));
> +#endif
> +
> +#endif /* _ASM_ARM_XEN_INTERFACE_H */
> diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> new file mode 100644
> index 0000000..0bad594
> --- /dev/null
> +++ b/arch/arm/xen/Makefile
> @@ -0,0 +1 @@
> +obj-y		:= enlighten.o
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> new file mode 100644
> index 0000000..d27c2a6
> --- /dev/null
> +++ b/arch/arm/xen/enlighten.c
> @@ -0,0 +1,35 @@
> +#include <xen/xen.h>
> +#include <xen/interface/xen.h>
> +#include <xen/interface/memory.h>
> +#include <xen/platform_pci.h>
> +#include <asm/xen/hypervisor.h>
> +#include <asm/xen/hypercall.h>
> +#include <linux/module.h>
> +
> +struct start_info _xen_start_info;
> +struct start_info *xen_start_info = &_xen_start_info;
> +EXPORT_SYMBOL_GPL(xen_start_info);
> +
> +enum xen_domain_type xen_domain_type = XEN_NATIVE;
> +EXPORT_SYMBOL_GPL(xen_domain_type);
> +
> +struct shared_info xen_dummy_shared_info;
> +struct shared_info *HYPERVISOR_shared_info = (void
*)&xen_dummy_shared_info;
> +
> +DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
> +
> +/* XXX: to be removed */
> +__read_mostly int xen_have_vector_callback;
> +EXPORT_SYMBOL_GPL(xen_have_vector_callback);
> +
> +int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
> +EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
> +
> +int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> +			       unsigned long addr,
> +			       unsigned long mfn, int nr,
> +			       pgprot_t prot, unsigned domid)
> +{
> +	return -ENOSYS;
> +}
> +EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> diff --git a/include/xen/xen.h b/include/xen/xen.h
> index a164024..2c0d3a5 100644
> --- a/include/xen/xen.h
> +++ b/include/xen/xen.h
> @@ -23,7 +23,7 @@ extern enum xen_domain_type xen_domain_type;
>  #include <xen/interface/xen.h>
>  #include <asm/xen/hypervisor.h>
>  
> -#define xen_initial_domain()	(xen_pv_domain() && \
> +#define xen_initial_domain()	(xen_domain() && \
>  				 xen_start_info->flags & SIF_INITDOMAIN)
>  #else  /* !CONFIG_XEN_DOM0 */
>  #define xen_initial_domain()	(0)
>

Ian Campbell

2012-Aug-02 07:35 UTC

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Re: [PATCH 01/24] arm: initial Xen support

On Wed, 2012-08-01 at 19:27 +0100, Rob Herring wrote:> On 07/26/2012 10:33 AM, Stefano Stabellini wrote:
> > - Basic hypervisor.h and interface.h definitions.
> > - Skelethon enlighten.c, set xen_start_info to an empty struct.
> > - Do not limit xen_initial_domain to PV guests.
> > 
> > The new code only compiles when CONFIG_XEN is set, that is going to be
> > added to arch/arm/Kconfig in a later patch.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > ---
> >  arch/arm/Makefile                     |    1 +
> >  arch/arm/include/asm/hypervisor.h     |    6 +++
> >  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
> >  arch/arm/include/asm/xen/interface.h  |   64
+++++++++++++++++++++++++++++++++
> 
> These headers don''t seem particularly ARM specific. Could they be
moved
> to asm-generic or include/linux?
Or perhaps include/xen.

A bunch of it also looks like x86 specific stuff which has crept in.
e.g. PARAVIRT_LAZY_FOO and paravirt_get_lazy_mode() are arch/x86
specific and shouldn''t be called from common code (and aren''t,
AFAICT).

Konrad Rzeszutek Wilk

2012-Aug-02 14:13 UTC

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Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

On Thu, Aug 02, 2012 at 08:35:51AM +0100, Ian Campbell
wrote:> On Wed, 2012-08-01 at 19:27 +0100, Rob Herring wrote:
> > On 07/26/2012 10:33 AM, Stefano Stabellini wrote:
> > > - Basic hypervisor.h and interface.h definitions.
> > > - Skelethon enlighten.c, set xen_start_info to an empty struct.
> > > - Do not limit xen_initial_domain to PV guests.
> > > 
> > > The new code only compiles when CONFIG_XEN is set, that is going
to be
> > > added to arch/arm/Kconfig in a later patch.
> > > 
> > > Signed-off-by: Stefano Stabellini
<stefano.stabellini-mvvWK6WmYclDPfheJLI6IQ@public.gmane.org>
> > > ---
> > >  arch/arm/Makefile                     |    1 +
> > >  arch/arm/include/asm/hypervisor.h     |    6 +++
> > >  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
> > >  arch/arm/include/asm/xen/interface.h  |   64
+++++++++++++++++++++++++++++++++
> > 
> > These headers don''t seem particularly ARM specific. Could
they be moved
> > to asm-generic or include/linux?
> 
> Or perhaps include/xen.
> 
> A bunch of it also looks like x86 specific stuff which has crept in.
> e.g. PARAVIRT_LAZY_FOO and paravirt_get_lazy_mode() are arch/x86
> specific and shouldn''t be called from common code (and
aren''t, AFAICT).
The could be moved out..

Stefano Stabellini

2012-Aug-06 10:31 UTC

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Re: [PATCH 15/24] xen/arm: receive Xen events on ARM

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:57PM +0100, Stefano Stabellini wrote:
> > Compile events.c on ARM.
> > Parse, map and enable the IRQ to get event notifications from the
device
> > tree (node "/xen").
> > 
> > On ARM Linux irqs are not enabled by default:
> > 
> > - call enable_percpu_irq for xen_events_irq (drivers are supposed
> > to call enable_irq after request_irq);
> > 
> > - reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by
> > default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn''t
call
> > irq_startup, that is responsible for calling irq_unmask at startup
time.
> > As a result event channels remain masked.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/xen/enlighten.c |   33 +++++++++++++++++++++++++++++++++
> >  arch/x86/xen/enlighten.c |    1 +
> >  arch/x86/xen/irq.c       |    1 +
> >  arch/x86/xen/xen-ops.h   |    1 -
> >  drivers/xen/events.c     |   18 +++++++++++++++---
> >  include/xen/events.h     |    2 ++
> >  6 files changed, 52 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index 854af1e..60d6d36 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -7,8 +7,11 @@
> >  #include <xen/grant_table.h>
> >  #include <xen/hvm.h>
> >  #include <xen/xenbus.h>
> > +#include <xen/events.h>
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irqreturn.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> >  #include <linux/of_irq.h>
> > @@ -33,6 +36,8 @@ EXPORT_SYMBOL_GPL(xen_have_vector_callback);
> >  int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
> >  EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
> >  
> > +static __read_mostly int xen_events_irq = -1;
> > +
> >  int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> >  			       unsigned long addr,
> >  			       unsigned long mfn, int nr,
> > @@ -65,6 +70,9 @@ int __init xen_guest_init(void)
> >  	if (of_address_to_resource(node, 0, &res))
> >  		return -EINVAL;
> >  	xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
> > +	xen_events_irq = irq_of_parse_and_map(node, 0);
> > +	pr_info("Xen support found, events_irq=%d
gnttab_frame_pfn=%lx\n",
> > +			xen_events_irq, xen_hvm_resume_frames);
> >  	xen_domain_type = XEN_HVM_DOMAIN;
> >  
> >  	xen_setup_features();
> > @@ -114,3 +122,28 @@ int __init xen_guest_init(void)
> >  }
> >  EXPORT_SYMBOL_GPL(xen_guest_init);
> >  core_initcall(xen_guest_init);
> > +
> > +static irqreturn_t xen_arm_callback(int irq, void *arg)
> > +{
> > +	xen_hvm_evtchn_do_upcall();
> > +	return 0;
> 
> Um, IRQ_HANDLED?
Yep

> > +}
> > +
> > +static int __init xen_init_events(void)
> > +{
> > +	if (!xen_domain() || xen_events_irq < 0)
> > +		return -ENODEV;
> > +
> > +	xen_init_IRQ();
> > +
> > +	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
> > +			"events", xen_vcpu)) {
> > +		pr_err("Error requesting IRQ %d\n", xen_events_irq);
> > +		return -EINVAL;
> > +	}
> > +
> > +	enable_percpu_irq(xen_events_irq, 0);
> > +
> > +	return 0;
> > +}
> > +postcore_initcall(xen_init_events);
> > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> > index 6131d43..5a30502 100644
> > --- a/arch/x86/xen/enlighten.c
> > +++ b/arch/x86/xen/enlighten.c
> > @@ -33,6 +33,7 @@
> >  #include <linux/memblock.h>
> >  
> >  #include <xen/xen.h>
> > +#include <xen/events.h>
> >  #include <xen/interface/xen.h>
> >  #include <xen/interface/version.h>
> >  #include <xen/interface/physdev.h>
> > diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
> > index 1573376..01a4dc0 100644
> > --- a/arch/x86/xen/irq.c
> > +++ b/arch/x86/xen/irq.c
> > @@ -5,6 +5,7 @@
> >  #include <xen/interface/xen.h>
> >  #include <xen/interface/sched.h>
> >  #include <xen/interface/vcpu.h>
> > +#include <xen/events.h>
> >  
> >  #include <asm/xen/hypercall.h>
> >  #include <asm/xen/hypervisor.h>
> > diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
> > index 202d4c1..2368295 100644
> > --- a/arch/x86/xen/xen-ops.h
> > +++ b/arch/x86/xen/xen-ops.h
> > @@ -35,7 +35,6 @@ void xen_set_pat(u64);
> >  
> >  char * __init xen_memory_setup(void);
> >  void __init xen_arch_setup(void);
> > -void __init xen_init_IRQ(void);
> >  void xen_enable_sysenter(void);
> >  void xen_enable_syscall(void);
> >  void xen_vcpu_restore(void);
> > diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> > index 7da65d3..9b506b2 100644
> > --- a/drivers/xen/events.c
> > +++ b/drivers/xen/events.c
> > @@ -31,14 +31,16 @@
> >  #include <linux/irqnr.h>
> >  #include <linux/pci.h>
> >  
> > +#ifdef CONFIG_X86
> >  #include <asm/desc.h>
> >  #include <asm/ptrace.h>
> >  #include <asm/irq.h>
> >  #include <asm/idle.h>
> >  #include <asm/io_apic.h>
> > -#include <asm/sync_bitops.h>
> >  #include <asm/xen/page.h>
> >  #include <asm/xen/pci.h>
> > +#endif
> > +#include <asm/sync_bitops.h>
> >  #include <asm/xen/hypercall.h>
> >  #include <asm/xen/hypervisor.h>
> >  
> > @@ -50,6 +52,9 @@
> >  #include <xen/interface/event_channel.h>
> >  #include <xen/interface/hvm/hvm_op.h>
> >  #include <xen/interface/hvm/params.h>
> > +#include <xen/interface/physdev.h>
> > +#include <xen/interface/sched.h>
> > +#include <asm/hw_irq.h>
> >  
> >  /*
> >   * This lock protects updates to the following mapping and
reference-count
> > @@ -834,6 +839,7 @@ int bind_evtchn_to_irq(unsigned int evtchn)
> >  		struct irq_info *info = info_for_irq(irq);
> >  		WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
> >  	}
> > +	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
> 
> I feel that this should be its own commit by itself. I am not certain
> of the implication of this on x86 and I think it deserves some explanation.
OK. It shouldn''t have any effects on x86, considering that both
IRQ_NOREQUEST and IRQ_NOAUTOEN are not set there.

> >  
> >  out:
> >  	mutex_unlock(&irq_mapping_update_lock);
> > @@ -1377,7 +1383,9 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
> >  {
> >  	struct pt_regs *old_regs = set_irq_regs(regs);
> >  
> > +#ifdef CONFIG_X86
> >  	exit_idle();
> > +#endif
> 
> Doesn''t exist? Or is that it does not need it?
It does not exist.

Stefano Stabellini

2012-Aug-06 10:46 UTC

head link

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

On Thu, 2 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Aug 02, 2012 at 08:35:51AM +0100, Ian Campbell wrote:
> > On Wed, 2012-08-01 at 19:27 +0100, Rob Herring wrote:
> > > On 07/26/2012 10:33 AM, Stefano Stabellini wrote:
> > > > - Basic hypervisor.h and interface.h definitions.
> > > > - Skelethon enlighten.c, set xen_start_info to an empty
struct.
> > > > - Do not limit xen_initial_domain to PV guests.
> > > > 
> > > > The new code only compiles when CONFIG_XEN is set, that is
going to be
> > > > added to arch/arm/Kconfig in a later patch.
> > > > 
> > > > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > > > ---
> > > >  arch/arm/Makefile                     |    1 +
> > > >  arch/arm/include/asm/hypervisor.h     |    6 +++
> > > >  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
> > > >  arch/arm/include/asm/xen/interface.h  |   64
+++++++++++++++++++++++++++++++++
> > > 
> > > These headers don''t seem particularly ARM specific.
Could they be moved
> > > to asm-generic or include/linux?
> > 
> > Or perhaps include/xen.
> > 
> > A bunch of it also looks like x86 specific stuff which has crept in.
> > e.g. PARAVIRT_LAZY_FOO and paravirt_get_lazy_mode() are arch/x86
> > specific and shouldn''t be called from common code (and
aren''t, AFAICT).
> 
> The could be moved out..
> 
they are called from grant-table.c; sigh, I was the one to add them there :-(

interface.h is ARM specific, except for the pvclock structs, that in
fact are marked "XXX".

hypervisor.h is almost empty but I guess I could move out the following two
lines:

extern struct shared_info *HYPERVISOR_shared_info;
extern struct start_info *xen_start_info;

Considering that each arch is free to map them (or not) the way it
wants, I don''t think is a good idea.

Stefano Stabellini

2012-Aug-06 10:55 UTC

head link

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> > > > +struct pvclock_wall_clock {
> > > > +	u32   version;
> > > > +	u32   sec;
> > > > +	u32   nsec;
> > > > +} __attribute__((__packed__));
> > > 
> > > That is weird. It is 4+4+4 = 12 bytes? Don''t you want it
to be 16 bytes?
> > 
> > I agree that 16 bytes would be a better choice, but it needs to match
> > the struct in Xen that is defined as follow:
> > 
> >     uint32_t wc_version;      /* Version counter: see
vcpu_time_info_t. */
> >     uint32_t wc_sec;          /* Secs  00:00:00 UTC, Jan 1, 1970.  */
> >     uint32_t wc_nsec;         /* Nsecs 00:00:00 UTC, Jan 1, 1970.  */
> 
> Would it make sense to add some paddigin then at least? In both
> cases? Or is it too late for this?
I can see why adding some padding would be useful if the structs were
not packed and we wanted to enforce 32/64 bit compatibility on x86.
However on ARM the field alignments on 32 and 64 bits are the same for
integer values so the padding wouldn''t make a difference.
In any case both structs are packed, so the alignment is forced to be the
same by the compiler.

Stefano Stabellini

2012-Aug-06 11:17 UTC

head link

Re: [PATCH 09/24] xen/arm: compile and run xenbus

On Wed, 1 Aug 2012, Konrad Rzeszutek Wilk wrote:> On Thu, Jul 26, 2012 at 04:33:51PM +0100, Stefano Stabellini wrote:
> > bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not
> > an error.
> > 
> > If Linux is running as an HVM domain and is running as Dom0, use
> > xenstored_local_init to initialize the xenstore page and event
channel.
> > 
> > Signed-off-by: Stefano Stabellini
<stefano.stabellini@eu.citrix.com>
> > ---
> >  drivers/xen/xenbus/xenbus_comms.c |    2 +-
> >  drivers/xen/xenbus/xenbus_probe.c |   27 +++++++++++++++++----------
> >  drivers/xen/xenbus/xenbus_xs.c    |    1 +
> >  3 files changed, 19 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/xen/xenbus/xenbus_comms.c
b/drivers/xen/xenbus/xenbus_comms.c
> > index 52fe7ad..c5aa55c 100644
> > --- a/drivers/xen/xenbus/xenbus_comms.c
> > +++ b/drivers/xen/xenbus/xenbus_comms.c
> > @@ -224,7 +224,7 @@ int xb_init_comms(void)
> >  		int err;
> >  		err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
> >  						0, "xenbus", &xb_waitq);
> > -		if (err <= 0) {
> > +		if (err < 0) {
> >  			printk(KERN_ERR "XENBUS request irq failed %i\n", err);
> >  			return err;
> >  		}
> > diff --git a/drivers/xen/xenbus/xenbus_probe.c
b/drivers/xen/xenbus/xenbus_probe.c
> > index b793723..3ae47c2 100644
> > --- a/drivers/xen/xenbus/xenbus_probe.c
> > +++ b/drivers/xen/xenbus/xenbus_probe.c
> > @@ -729,16 +729,23 @@ static int __init xenbus_init(void)
> >  	xenbus_ring_ops_init();
> >  
> >  	if (xen_hvm_domain()) {
> > -		uint64_t v = 0;
> > -		err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
> > -		if (err)
> > -			goto out_error;
> > -		xen_store_evtchn = (int)v;
> > -		err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> > -		if (err)
> > -			goto out_error;
> > -		xen_store_mfn = (unsigned long)v;
> > -		xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT,
PAGE_SIZE);
> > +		if (xen_initial_domain()) {
> > +			err = xenstored_local_init();
> > +			xen_store_interface > > +				phys_to_virt(xen_store_mfn
<< PAGE_SHIFT);
> > +		} else {
> > +			uint64_t v = 0;
> > +			err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
> > +			if (err)
> > +				goto out_error;
> > +			xen_store_evtchn = (int)v;
> > +			err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> > +			if (err)
> > +				goto out_error;
> > +			xen_store_mfn = (unsigned long)v;
> > +			xen_store_interface > > +				ioremap(xen_store_mfn <<
PAGE_SHIFT, PAGE_SIZE);
> > +		}
> 
> This, and along with the Hybrid PV dom0 (not yet posted, but it was doing
> similar manipulation here) is getting more and more like a rat-mess.
> 
> 
> Any chance we can just abstract the three different XenStore access
> ways and just have something like this:
> 
> 	enum {
> 		USE_UNKNOWN
> 		USE_HVM,
> 		USE_PV,
> 		USE_LOCAL
> 		USE_ALREADY_INIT
> 	};
> 	int usage = USE_UNKNOWN;
> 	if (xen_pv_domain())
> 		usage = USE_PV;
> 	if (xen_hvm_domain())
> 		usage = USE_HVM;
> 	if (xen_initial_domain())
> 		usage = USE_LOCAL;
> 
> 	if (xen_start_info->store_evtchn)
> 		usage = USE_ALREADY_INIT;
> 	
> 	.. other overwrites..
> 
> 	switch (usage) {
> 		.. blah blah.
> 	}
I''ll give it a try.

Xen devel - Jul 2012 - [PATCH 00/24] Introduce Xen support on ARM

[PATCH 00/24] Introduce Xen support on ARM

[PATCH 01/24] arm: initial Xen support

[PATCH 02/24] xen/arm: hypercalls

[PATCH 03/24] xen/arm: page.h definitions

[PATCH 04/24] xen/arm: sync_bitops

[PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions

[PATCH 06/24] xen: missing includes

[PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

[PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types

[PATCH 09/24] xen/arm: compile and run xenbus

[PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM

[PATCH 11/24] xen/arm: introduce CONFIG_XEN on ARM

[PATCH 12/24] xen/arm: Introduce xen_guest_init

[PATCH 13/24] xen/arm: get privilege status

[PATCH 14/24] xen/arm: initialize grant_table on ARM

[PATCH 15/24] xen/arm: receive Xen events on ARM

[PATCH 16/24] xen/arm: implement alloc/free_xenballooned_pages with alloc_pages/kfree

[PATCH 17/24] xen: allow privcmd for HVM guests

[PATCH 18/24] xen/arm: compile blkfront and blkback

[PATCH 19/24] xen/arm: compile netback

[PATCH 20/24] xen: update xen_add_to_physmap interface

[PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present

[PATCH 22/24] ARM: enable earlyprintk=xen

[PATCH 23/24] hvc_xen: allow dom0_write_console for HVM guests

[PATCH 24/24] [HACK] xen/arm: implement xen_remap_domain_mfn_range

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 03/24] xen/arm: page.h definitions

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 06/24] xen: missing includes

Re: [Xen-devel] [PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM

Re: [Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

Re: [PATCH 13/24] xen/arm: get privilege status

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

Re: [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 03/24] xen/arm: page.h definitions

Re: [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [PATCH 13/24] xen/arm: get privilege status

Re: [PATCH 13/24] xen/arm: get privilege status

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

Re: [Xen-devel] [PATCH 06/24] xen: missing includes

Re: [Xen-devel] [PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM

Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

Re: [PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions

Re: [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping

Re: [PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types

Re: [PATCH 09/24] xen/arm: compile and run xenbus

Re: [Xen-devel] [PATCH 11/24] xen/arm: introduce CONFIG_XEN on ARM

Re: [Xen-devel] [PATCH 04/24] xen/arm: sync_bitops

Re: [PATCH 12/24] xen/arm: Introduce xen_guest_init

Re: [PATCH 13/24] xen/arm: get privilege status

Re: [PATCH 14/24] xen/arm: initialize grant_table on ARM

Re: [PATCH 15/24] xen/arm: receive Xen events on ARM

Re: [Xen-devel] [PATCH 17/24] xen: allow privcmd for HVM guests

Re: [PATCH 18/24] xen/arm: compile blkfront and blkback

Re: [PATCH 20/24] xen: update xen_add_to_physmap interface

Re: [PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present