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[2/5] KVM: MMU: Optimize gpte_access() slightly

Message ID 1347460194-11807-3-git-send-email-avi@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Avi Kivity Sept. 12, 2012, 2:29 p.m. UTC
If nx is disabled, then is gpte[63] is set we will hit a reserved
bit set fault before checking permissions; so we can ignore the
setting of efer.nxe.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 arch/x86/kvm/paging_tmpl.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Comments

Xiao Guangrong Sept. 13, 2012, 11:36 a.m. UTC | #1
On 09/12/2012 10:29 PM, Avi Kivity wrote:
> If nx is disabled, then is gpte[63] is set we will hit a reserved
> bit set fault before checking permissions; so we can ignore the
> setting of efer.nxe.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>

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diff mbox

Patch

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index bf7b4ff..064bcb3 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -106,10 +106,8 @@  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 (vcpu->arch.mmu.nx)
-		access &= ~(gpte >> PT64_NX_SHIFT);
+	access &= ~(gpte >> PT64_NX_SHIFT);
 #endif
 	return access;
 }