[PATCH 42/48] KVM: MMU: Fix is_dirty_pte()

From: Avi Kivity
Date: Sun Aug 16 2009 - 05:31:29 EST


is_dirty_pte() is used on guest ptes, not shadow ptes, so it needs to avoid
shadow_dirty_mask and use PT_DIRTY_MASK instead.

Misdetecting dirty pages could lead to unnecessarily setting the dirty bit
under EPT.

Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8ee67e3..8f2cb29 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -242,7 +242,7 @@ static int is_writeble_pte(unsigned long pte)

static int is_dirty_pte(unsigned long pte)
{
- return pte & shadow_dirty_mask;
+ return pte & PT_DIRTY_MASK;
}

static int is_rmap_pte(u64 pte)
--
1.6.3.3

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