Linux Virtualization - Mar 2018 - [PATCH v5 2/7] PCI: Scan all functions when running over Jailhouse

Basic x86 support [1] for running Linux as secondary Jailhouse [2] guest
is currently pending in the tip tree. This builds on top and enhances
the PCI support for x86 and also ARM guests (ARM[64] does not require
platform patches and works already).

Key elements of this series are:
 - detection of Jailhouse via device tree hypervisor node
 - function-level PCI scan if Jailhouse is detected
 - MMCONFIG support for x86 guests

As most changes affect x86, I would suggest to route the series also via
tip after the necessary acks are collected.

Changes in v5:
 - fix build breakage of patch 6 on i386

Changes in v4:
 - slit up Kconfig changes
 - respect pcibios_last_bus during mmconfig setup
 - cosmetic changes requested by Andy

Changes in v3:
 - avoided duplicate scans of PCI functions under Jailhouse
 - reformated PCI_MMCONFIG condition and rephrase related commit log

Changes in v2:
 - adjusted commit log and include ordering in patch 2
 - rebased over Linus master

Jan

[1] https://lkml.org/lkml/2017/11/27/125
[2] http://jailhouse-project.org

CC: Benedikt Spranger <b.spranger at linutronix.de>
CC: Juergen Gross <jgross at suse.com>
CC: Mark Rutland <mark.rutland at arm.com>
CC: Otavio Pontes <otavio.pontes at intel.com>
CC: Rob Herring <robh+dt at kernel.org>

Jan Kiszka (6):
  jailhouse: Provide detection for non-x86 systems
  PCI: Scan all functions when running over Jailhouse
  x86: Align x86_64 PCI_MMCONFIG with 32-bit variant
  x86: Consolidate PCI_MMCONFIG configs
  x86/jailhouse: Allow to use PCI_MMCONFIG without ACPI
  MAINTAINERS: Add entry for Jailhouse

Otavio Pontes (1):
  x86/jailhouse: Enable PCI mmconfig access in inmates

 Documentation/devicetree/bindings/jailhouse.txt |  8 ++++++++
 MAINTAINERS                                     |  7 +++++++
 arch/x86/Kconfig                                | 12 +++++++-----
 arch/x86/include/asm/jailhouse_para.h           |  2 +-
 arch/x86/include/asm/pci_x86.h                  |  2 ++
 arch/x86/kernel/Makefile                        |  2 +-
 arch/x86/kernel/cpu/amd.c                       |  2 +-
 arch/x86/kernel/jailhouse.c                     |  8 ++++++++
 arch/x86/pci/legacy.c                           |  4 +++-
 arch/x86/pci/mmconfig-shared.c                  |  4 ++--
 drivers/pci/probe.c                             | 22 +++++++++++++++++++---
 include/linux/hypervisor.h                      | 17 +++++++++++++++--
 12 files changed, 74 insertions(+), 16 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/jailhouse.txt

-- 
2.13.6

From: Jan Kiszka <jan.kiszka at siemens.com>

Implement jailhouse_paravirt() via device tree probing on architectures
!= x86. Will be used by the PCI core.

CC: Rob Herring <robh+dt at kernel.org>
CC: Mark Rutland <mark.rutland at arm.com>
CC: Juergen Gross <jgross at suse.com>
Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
Reviewed-by: Juergen Gross <jgross at suse.com>
---
 Documentation/devicetree/bindings/jailhouse.txt |  8 ++++++++
 arch/x86/include/asm/jailhouse_para.h           |  2 +-
 include/linux/hypervisor.h                      | 17 +++++++++++++++--
 3 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/jailhouse.txt

diff --git a/Documentation/devicetree/bindings/jailhouse.txt
b/Documentation/devicetree/bindings/jailhouse.txt
new file mode 100644
index 000000000000..2901c25ff340
--- /dev/null
+++ b/Documentation/devicetree/bindings/jailhouse.txt
@@ -0,0 +1,8 @@
+Jailhouse non-root cell device tree bindings
+--------------------------------------------
+
+When running in a non-root Jailhouse cell (partition), the device tree of this
+platform shall have a top-level "hypervisor" node with the following
+properties:
+
+- compatible = "jailhouse,cell"
diff --git a/arch/x86/include/asm/jailhouse_para.h
b/arch/x86/include/asm/jailhouse_para.h
index 875b54376689..b885a961a150 100644
--- a/arch/x86/include/asm/jailhouse_para.h
+++ b/arch/x86/include/asm/jailhouse_para.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL2.0 */
 
 /*
- * Jailhouse paravirt_ops implementation
+ * Jailhouse paravirt detection
  *
  * Copyright (c) Siemens AG, 2015-2017
  *
diff --git a/include/linux/hypervisor.h b/include/linux/hypervisor.h
index b19563f9a8eb..fc08b433c856 100644
--- a/include/linux/hypervisor.h
+++ b/include/linux/hypervisor.h
@@ -8,15 +8,28 @@
  */
 
 #ifdef CONFIG_X86
+
+#include <asm/jailhouse_para.h>
 #include <asm/x86_init.h>
+
 static inline void hypervisor_pin_vcpu(int cpu)
 {
 	x86_platform.hyper.pin_vcpu(cpu);
 }
-#else
+
+#else /* !CONFIG_X86 */
+
+#include <linux/of.h>
+
 static inline void hypervisor_pin_vcpu(int cpu)
 {
 }
-#endif
+
+static inline bool jailhouse_paravirt(void)
+{
+	return of_find_compatible_node(NULL, NULL, "jailhouse,cell");
+}
+
+#endif /* !CONFIG_X86 */
 
 #endif /* __LINUX_HYPEVISOR_H */
-- 
2.13.6

From: Jan Kiszka <jan.kiszka at siemens.com>

Per PCIe r4.0, sec 7.5.1.1.9, multi-function devices are required to
have a function 0.  Therefore, Linux scans for devices at function 0
(devfn 0/8/16/...) and only scans for other functions if function 0
has its Multi-Function Device bit set or ARI or SR-IOV indicate
there are more functions.

The Jailhouse hypervisor may pass individual functions of a
multi-function device to a guest without passing function 0, which
means a Linux guest won't find them.

Change Linux PCI probing so it scans all function numbers when
running as a guest over Jailhouse.

This is technically prohibited by the spec, so it is possible that
PCI devices without the Multi-Function Device bit set may have
unexpected behavior in response to this probe.

Derived from original patch by Benedikt Spranger.

CC: Benedikt Spranger <b.spranger at linutronix.de>
Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
Acked-by: Bjorn Helgaas <bhelgaas at google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>
---
 arch/x86/pci/legacy.c |  4 +++-
 drivers/pci/probe.c   | 22 +++++++++++++++++++---
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/arch/x86/pci/legacy.c b/arch/x86/pci/legacy.c
index 1cb01abcb1be..dfbe6ac38830 100644
--- a/arch/x86/pci/legacy.c
+++ b/arch/x86/pci/legacy.c
@@ -4,6 +4,7 @@
 #include <linux/init.h>
 #include <linux/export.h>
 #include <linux/pci.h>
+#include <asm/jailhouse_para.h>
 #include <asm/pci_x86.h>
 
 /*
@@ -34,13 +35,14 @@ int __init pci_legacy_init(void)
 
 void pcibios_scan_specific_bus(int busn)
 {
+	int stride = jailhouse_paravirt() ? 1 : 8;
 	int devfn;
 	u32 l;
 
 	if (pci_find_bus(0, busn))
 		return;
 
-	for (devfn = 0; devfn < 256; devfn += 8) {
+	for (devfn = 0; devfn < 256; devfn += stride) {
 		if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) &&
 		    l != 0x0000 && l != 0xffff) {
 			DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ef5377438a1e..3c365dc996e7 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -16,6 +16,7 @@
 #include <linux/pci-aspm.h>
 #include <linux/aer.h>
 #include <linux/acpi.h>
+#include <linux/hypervisor.h>
 #include <linux/irqdomain.h>
 #include <linux/pm_runtime.h>
 #include "pci.h"
@@ -2518,14 +2519,29 @@ static unsigned int pci_scan_child_bus_extend(struct
pci_bus *bus,
 {
 	unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0;
 	unsigned int start = bus->busn_res.start;
-	unsigned int devfn, cmax, max = start;
+	unsigned int devfn, fn, cmax, max = start;
 	struct pci_dev *dev;
+	int nr_devs;
 
 	dev_dbg(&bus->dev, "scanning bus\n");
 
 	/* Go find them, Rover! */
-	for (devfn = 0; devfn < 0x100; devfn += 8)
-		pci_scan_slot(bus, devfn);
+	for (devfn = 0; devfn < 256; devfn += 8) {
+		nr_devs = pci_scan_slot(bus, devfn);
+
+		/*
+		 * The Jailhouse hypervisor may pass individual functions of a
+		 * multi-function device to a guest without passing function 0.
+		 * Look for them as well.
+		 */
+		if (jailhouse_paravirt() && nr_devs == 0) {
+			for (fn = 1; fn < 8; fn++) {
+				dev = pci_scan_single_device(bus, devfn + fn);
+				if (dev)
+					dev->multifunction = 1;
+			}
+		}
+	}
 
 	/* Reserve buses for SR-IOV capability */
 	used_buses = pci_iov_bus_range(bus);
-- 
2.13.6

From: Otavio Pontes <otavio.pontes at intel.com>

Use the PCI mmconfig base address exported by jailhouse in boot
parameters in order to access the memory mapped PCI configuration space.

Signed-off-by: Otavio Pontes <otavio.pontes at intel.com>
[Jan: rebased, fixed !CONFIG_PCI_MMCONFIG, used pcibios_last_bus]
Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>
---
 arch/x86/include/asm/pci_x86.h | 2 ++
 arch/x86/kernel/jailhouse.c    | 8 ++++++++
 arch/x86/pci/mmconfig-shared.c | 4 ++--
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index eb66fa9cd0fc..959d618dbb17 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -151,6 +151,8 @@ extern int pci_mmconfig_insert(struct device *dev, u16 seg,
u8 start, u8 end,
 			       phys_addr_t addr);
 extern int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
 extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
+extern struct pci_mmcfg_region *__init pci_mmconfig_add(int segment, int start,
+							int end, u64 addr);
 
 extern struct list_head pci_mmcfg_list;
 
diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index b68fd895235a..fa183a131edc 100644
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -124,6 +124,14 @@ static int __init jailhouse_pci_arch_init(void)
 	if (pcibios_last_bus < 0)
 		pcibios_last_bus = 0xff;
 
+#ifdef CONFIG_PCI_MMCONFIG
+	if (setup_data.pci_mmconfig_base) {
+		pci_mmconfig_add(0, 0, pcibios_last_bus,
+				 setup_data.pci_mmconfig_base);
+		pci_mmcfg_arch_init();
+	}
+#endif
+
 	return 0;
 }
 
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 96684d0adcf9..0e590272366b 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -94,8 +94,8 @@ static struct pci_mmcfg_region *pci_mmconfig_alloc(int
segment, int start,
 	return new;
 }
 
-static struct pci_mmcfg_region *__init pci_mmconfig_add(int segment, int start,
-							int end, u64 addr)
+struct pci_mmcfg_region *__init pci_mmconfig_add(int segment, int start,
+						 int end, u64 addr)
 {
 	struct pci_mmcfg_region *new;
 
-- 
2.13.6

From: Jan Kiszka <jan.kiszka at siemens.com>

Allow to enable PCI_MMCONFIG when only SFI is present and make this
option default on. This will help consolidating both into one Kconfig
statement.

Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
---
 arch/x86/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index eb7f43f23521..c19f5342ec2b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2659,7 +2659,8 @@ config PCI_DOMAINS
 
 config PCI_MMCONFIG
 	bool "Support mmconfig PCI config space access"
-	depends on X86_64 && PCI && ACPI
+	default y
+	depends on X86_64 && PCI && (ACPI || SFI)
 
 config PCI_CNB20LE_QUIRK
 	bool "Read CNB20LE Host Bridge Windows" if EXPERT
-- 
2.13.6

From: Jan Kiszka <jan.kiszka at siemens.com>

Since e279b6c1d329 ("x86: start unification of arch/x86/Kconfig.*"),
we
have two PCI_MMCONFIG entries, one from the original i386 and another
from x86_64. This consolidates both entries into a single one.

Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
---
 arch/x86/Kconfig | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c19f5342ec2b..8986a6b6e3df 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2641,8 +2641,10 @@ config PCI_DIRECT
 	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC
|| PCI_GOMMCONFIG))
 
 config PCI_MMCONFIG
-	def_bool y
-	depends on X86_32 && PCI && (ACPI || SFI) &&
(PCI_GOMMCONFIG || PCI_GOANY)
+	bool "Support mmconfig PCI config space access" if X86_64
+	default y
+	depends on PCI && (ACPI || SFI)
+	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
 
 config PCI_OLPC
 	def_bool y
@@ -2657,11 +2659,6 @@ config PCI_DOMAINS
 	def_bool y
 	depends on PCI
 
-config PCI_MMCONFIG
-	bool "Support mmconfig PCI config space access"
-	default y
-	depends on X86_64 && PCI && (ACPI || SFI)
-
 config PCI_CNB20LE_QUIRK
 	bool "Read CNB20LE Host Bridge Windows" if EXPERT
 	depends on PCI
-- 
2.13.6

From: Jan Kiszka <jan.kiszka at siemens.com>

Jailhouse does not use ACPI, but it does support MMCONFIG. Make sure the
latter can be built without having to enable ACPI as well. Primarily, we
need to make the AMD mmconf-fam10h_64 depend upon MMCONFIG and ACPI,
instead of just the former.

Saves some bytes in the Jailhouse non-root kernel.

Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
---
 arch/x86/Kconfig          | 6 +++++-
 arch/x86/kernel/Makefile  | 2 +-
 arch/x86/kernel/cpu/amd.c | 2 +-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8986a6b6e3df..b53340e71f84 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2643,7 +2643,7 @@ config PCI_DIRECT
 config PCI_MMCONFIG
 	bool "Support mmconfig PCI config space access" if X86_64
 	default y
-	depends on PCI && (ACPI || SFI)
+	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
 	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
 
 config PCI_OLPC
@@ -2659,6 +2659,10 @@ config PCI_DOMAINS
 	def_bool y
 	depends on PCI
 
+config MMCONF_FAM10H
+	def_bool y
+	depends on X86_64 && PCI_MMCONFIG && ACPI
+
 config PCI_CNB20LE_QUIRK
 	bool "Read CNB20LE Host Bridge Windows" if EXPERT
 	depends on PCI
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 29786c87e864..73ccf80c09a2 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -146,6 +146,6 @@ ifeq ($(CONFIG_X86_64),y)
 	obj-$(CONFIG_GART_IOMMU)	+= amd_gart_64.o aperture_64.o
 	obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary_64.o tce_64.o
 
-	obj-$(CONFIG_PCI_MMCONFIG)	+= mmconf-fam10h_64.o
+	obj-$(CONFIG_MMCONF_FAM10H)	+= mmconf-fam10h_64.o
 	obj-y				+= vsmp_64.o
 endif
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index f0e6456ca7d3..12bc0a1139da 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -716,7 +716,7 @@ static void init_amd_k8(struct cpuinfo_x86 *c)
 
 static void init_amd_gh(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_MMCONF_FAM10H
 	/* do this for boot cpu */
 	if (c == &boot_cpu_data)
 		check_enable_amd_mmconf_dmi();
-- 
2.13.6

From: Jan Kiszka <jan.kiszka at siemens.com>

Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
---
 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 4623caf8d72d..6dc0b8f3ae0e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7523,6 +7523,13 @@ Q:	http://patchwork.linuxtv.org/project/linux-media/list/
 S:	Maintained
 F:	drivers/media/dvb-frontends/ix2505v*
 
+JAILHOUSE HYPERVISOR INTERFACE
+M:	Jan Kiszka <jan.kiszka at siemens.com>
+L:	jailhouse-dev at googlegroups.com
+S:	Maintained
+F:	arch/x86/kernel/jailhouse.c
+F:	arch/x86/include/asm/jailhouse_para.h
+
 JC42.4 TEMPERATURE SENSOR DRIVER
 M:	Guenter Roeck <linux at roeck-us.net>
 L:	linux-hwmon at vger.kernel.org
-- 
2.13.6