KVM: nSVM: Preserve IRQ/NMI/SMI priority irrespective of exiting behavior

Short circuit vmx_check_nested_events() if an unblocked IRQ/NMI/SMI is
pending and needs to be injected into L2, priority between coincident
events is not dependent on exiting behavior.

Fixes: b518ba9f ("KVM: nSVM: implement check_nested_events for interrupts")
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/nested.c

@@ -835,23 +835,29 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
 		kvm_event_needs_reinjection(vcpu) || svm->nested.exit_required ||
 		svm->nested.nested_run_pending;
 
-	if (vcpu->arch.smi_pending && nested_exit_on_smi(svm)) {
+	if (vcpu->arch.smi_pending && !svm_smi_blocked(vcpu)) {
 		if (block_nested_events)
 			return -EBUSY;
+		if (!nested_exit_on_smi(svm))
+			return 0;
 		nested_svm_smi(svm);
 		return 0;
 	}
 
-	if (vcpu->arch.nmi_pending && nested_exit_on_nmi(svm)) {
+	if (vcpu->arch.nmi_pending && !svm_nmi_blocked(vcpu)) {
 		if (block_nested_events)
 			return -EBUSY;
+		if (!nested_exit_on_nmi(svm))
+			return 0;
 		nested_svm_nmi(svm);
 		return 0;
 	}
 
-	if (kvm_cpu_has_interrupt(vcpu) && nested_exit_on_intr(svm)) {
+	if (kvm_cpu_has_interrupt(vcpu) && !svm_interrupt_blocked(vcpu)) {
 		if (block_nested_events)
 			return -EBUSY;
+		if (!nested_exit_on_intr(svm))
+			return 0;
 		nested_svm_intr(svm);
 		return 0;
 	}