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Diffstat (limited to 'arch/x86/xen/mmu.c')
-rw-r--r--arch/x86/xen/mmu.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 988828b479ed..69f5857660ac 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -353,8 +353,13 @@ static pteval_t pte_mfn_to_pfn(pteval_t val)
{
if (val & _PAGE_PRESENT) {
unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+ unsigned long pfn = mfn_to_pfn(mfn);
+
pteval_t flags = val & PTE_FLAGS_MASK;
- val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
+ if (unlikely(pfn == ~0))
+ val = flags & ~_PAGE_PRESENT;
+ else
+ val = ((pteval_t)pfn << PAGE_SHIFT) | flags;
}
return val;
@@ -1859,6 +1864,7 @@ pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
#endif /* CONFIG_X86_64 */
static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss;
+static unsigned char fake_ioapic_mapping[PAGE_SIZE] __page_aligned_bss;
static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
{
@@ -1899,7 +1905,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
* We just don't map the IO APIC - all access is via
* hypercalls. Keep the address in the pte for reference.
*/
- pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
+ pte = pfn_pte(PFN_DOWN(__pa(fake_ioapic_mapping)), PAGE_KERNEL);
break;
#endif
@@ -2064,6 +2070,7 @@ void __init xen_init_mmu_ops(void)
pv_mmu_ops = xen_mmu_ops;
memset(dummy_mapping, 0xff, PAGE_SIZE);
+ memset(fake_ioapic_mapping, 0xfd, PAGE_SIZE);
}
/* Protected by xen_reservation_lock. */