From: Avi Kivity <avi@redhat.com>
Date: Mon, 7 Mar 2011 12:54:28 +0000 (+0200)
Subject: KVM: VMX: Optimize vmx_get_cpl()
X-Git-Tag: android-x86-4.4-r1~6029^2~128
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=f4c63e5d5a356b652a3d984edbefca289176c40f;p=android-x86%2Fkernel.git

KVM: VMX: Optimize vmx_get_cpl()

In long mode, vm86 mode is disallowed, so we need not check for
it.  Reading rflags.vm may require a VMREAD, so it is expensive.

Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4d117072acf8..e8a35ee00735 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2120,7 +2120,8 @@ static int vmx_get_cpl(struct kvm_vcpu *vcpu)
 	if (!is_protmode(vcpu))
 		return 0;
 
-	if (kvm_get_rflags(vcpu) & X86_EFLAGS_VM) /* if virtual 8086 */
+	if (!is_long_mode(vcpu)
+	    && (kvm_get_rflags(vcpu) & X86_EFLAGS_VM)) /* if virtual 8086 */
 		return 3;
 
 	return vmcs_read16(GUEST_CS_SELECTOR) & 3;