Jeremy Fitzhardinge
2009-Mar-23 18:09 UTC
[Xen-devel] [PATCH 03/15] xen dom0: Set up basic IO permissions for dom0.
From: Juan Quintela <quintela@redhat.com>
Impact: set iopl for dom0 kernel; map ISA
Add the direct mapping area for ISA bus access, and enable IO space
access for the guest when running as dom0.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
arch/x86/xen/enlighten.c | 8 ++++++++
arch/x86/xen/mmu.c | 24 ++++++++++++++++++++++++
arch/x86/xen/setup.c | 6 +++++-
arch/x86/xen/xen-ops.h | 1 +
4 files changed, 38 insertions(+), 1 deletions(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index da33e0c..19af31b 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -989,6 +989,7 @@ asmlinkage void __init xen_start_kernel(void)
xen_raw_console_write("mapping kernel into physical memory\n");
pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
+ xen_ident_map_ISA();
init_mm.pgd = pgd;
@@ -998,6 +999,13 @@ asmlinkage void __init xen_start_kernel(void)
if (xen_feature(XENFEAT_supervisor_mode_kernel))
pv_info.kernel_rpl = 0;
+ if (xen_initial_domain()) {
+ struct physdev_set_iopl set_iopl;
+ set_iopl.iopl = 1;
+ if (HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl) == -1)
+ BUG();
+ }
+
/* set the limit of our address space */
xen_reserve_top();
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index b4e828c..e80e63c 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1635,6 +1635,7 @@ static void *m2v(phys_addr_t maddr)
return __ka(m2p(maddr));
}
+/* Set the page permissions on an identity-mapped pages */
static void set_page_prot(void *addr, pgprot_t prot)
{
unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
@@ -1860,6 +1861,29 @@ static void xen_set_fixmap(unsigned idx, unsigned long
phys, pgprot_t prot)
#endif
}
+__init void xen_ident_map_ISA(void)
+{
+ unsigned long pa;
+
+ /*
+ * If we''re dom0, then linear map the ISA machine addresses into
+ * the kernel''s address space.
+ */
+ if (!xen_initial_domain())
+ return;
+
+ xen_raw_printk("Xen: setup ISA identity maps\n");
+
+ for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) {
+ pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO);
+
+ if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0))
+ BUG();
+ }
+
+ xen_flush_tlb();
+}
+
__init void xen_post_allocator_init(void)
{
pv_mmu_ops.set_pte = xen_set_pte;
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 15c6c68..3e4cf46 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -51,6 +51,9 @@ char * __init xen_memory_setup(void)
* Even though this is normal, usable memory under Xen, reserve
* ISA memory anyway because too many things think they can poke
* about in there.
+ *
+ * In a dom0 kernel, this region is identity mapped with the
+ * hardware ISA area, so it really is out of bounds.
*/
e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
E820_RESERVED);
@@ -188,7 +191,8 @@ void __init xen_arch_setup(void)
pm_idle = xen_idle;
- paravirt_disable_iospace();
+ if (!xen_initial_domain())
+ paravirt_disable_iospace();
fiddle_vdso();
}
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 5c50a10..6ff6203 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -29,6 +29,7 @@ void xen_setup_machphys_mapping(void);
pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
void xen_ident_map_ISA(void);
void xen_reserve_top(void);
+void xen_ident_map_ISA(void);
void xen_post_allocator_init(void);
--
1.6.0.6
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