[patch 41/42] KVM: MMU: Fix torn shadow pte

[Greg KH]

2.6.26-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Avi Kivity <avi@xxxxxxxxxxxx>

(cherry picked from commit cd5998ebfbc9e6cb44408efa217c15d7eea13675)

The shadow code assigns a pte directly in one place, which is nonatomic on
i386 can can cause random memory references.  Fix by using an atomic setter.

Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/kvm/paging_tmpl.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -343,7 +343,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu
 		shadow_addr = __pa(shadow_page->spt);
 		shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
 			| PT_WRITABLE_MASK | PT_USER_MASK;
-		*shadow_ent = shadow_pte;
+		set_shadow_pte(shadow_ent, shadow_pte);
 	}
 
 	mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,

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