kvm: reduce couple for ACC_EXEC_MASK

PATCH New Lai Jiangshan 1 participant 1 message Apr 17, 2010

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x86 KVM KVM x86

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Lai Jiangshan

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2010-04-17 09:08 UTC #0 lore raw

PATCH 1/1 kvm: reduce couple for ACC_EXEC_MASK

The statement "access &= ~(gpte >> PT64_NX_SHIFT);" tries to clear bit ACC_EXEC_MASK actually. This statement relies PT64_NX_SHIFT==63&&ACC_EXEC_MASK=1

This patch reduces this couple.

Signed-off-by Lai Jiangshan <[email protected]>

---

arch/x86/kvm/paging_tmpl.h +3 -5

index 81eab9a..34f4aa2 100644
@@ -101,11 +101,9 @@ static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte)
 {
 	unsigned access;
 
-	access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK;
-#if PTTYPE == 64
-	if (is_nx(vcpu))
-		access &= ~(gpte >> PT64_NX_SHIFT);
-#endif
+	access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK));
+	if (PTTYPE != 64 || !is_nx(vcpu) || (gpte & PT64_NX_MASK))
+		access |= ACC_EXEC_MASK;
 	return access;
 }