[PATCH] KVM: MMU: Let the walker extract the target page gfn from the pte

This fixes a problem where set_pte_common() looked for shadowed pages based on
the page directory gfn (a huge page) instead of the actual gfn being mapped.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index ba813f49f8a..ceae25bfd4b 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -752,7 +752,8 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu,
                              u64 *shadow_pte,
                              gpa_t gaddr,
                              int dirty,
-                             u64 access_bits)
+                             u64 access_bits,
+                             gfn_t gfn)
 {
         hpa_t paddr;
 
@@ -779,10 +780,10 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu,
         if (access_bits & PT_WRITABLE_MASK) {
                 struct kvm_mmu_page *shadow;
 
-                shadow = kvm_mmu_lookup_page(vcpu, gaddr >> PAGE_SHIFT);
+                shadow = kvm_mmu_lookup_page(vcpu, gfn);
                 if (shadow) {
                         pgprintk("%s: found shadow page for %lx, marking ro\n",
-                                 __FUNCTION__, (gfn_t)(gaddr >> PAGE_SHIFT));
+                                 __FUNCTION__, gfn);
                         access_bits &= ~PT_WRITABLE_MASK;
                         *shadow_pte &= ~PT_WRITABLE_MASK;
                 }