[PATCH v2 1/5] mmu: extend the is_present check to 32 bits

Bandan Das
2016-07-12T22:19:23Z

This is safe because this function is called
on host controlled page table and non-present/non-MMIO
sptes never use bits 1..31. For the EPT case, this
ensures that cases where only the execute bit is set
is marked valid.

Signed-off-by: Bandan Das <bsd@redhat.com>
---
arch/x86/kvm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index def97b3..87b62dc 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -304,7 +304,7 @@ static int is_nx(struct kvm_vcpu *vcpu)

static int is_shadow_present_pte(u64 pte)
{
- return pte & PT_PRESENT_MASK && !is_mmio_spte(pte);
+ return (pte & 0xFFFFFFFFull) && !is_mmio_spte(pte);
}

static int is_large_pte(u64 pte)
--
2.5.5