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>
git-mirror · May 11, 2011 · f4c63e5 · f4c63e5
1 parent 6de1273
commit f4c63e5
Showing 1 changed file with 2 additions and 1 deletion.
diff --git 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;