KVM: Disable vapic support on Intel machines with FlexPriority

FlexPriority accelerates the tpr without any patching.

Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e7eac27..1f48ec8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -684,9 +684,11 @@
 	case KVM_CAP_USER_MEMORY:
 	case KVM_CAP_SET_TSS_ADDR:
 	case KVM_CAP_EXT_CPUID:
-	case KVM_CAP_VAPIC:
 		r = 1;
 		break;
+	case KVM_CAP_VAPIC:
+		r = !kvm_x86_ops->cpu_has_accelerated_tpr();
+		break;
 	default:
 		r = 0;
 		break;