KVM: Fix interrupt unhalting a vcpu when it shouldn't

kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
if interrupt window is actually opened.

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

virt/kvm/kvm_main.c

@@ -1610,7 +1610,8 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 	for (;;) {
 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
 
-		if (kvm_cpu_has_interrupt(vcpu) ||
+		if ((kvm_arch_interrupt_allowed(vcpu) &&
+					kvm_cpu_has_interrupt(vcpu)) ||
 				kvm_arch_vcpu_runnable(vcpu)) {
 			set_bit(KVM_REQ_UNHALT, &vcpu->requests);
 			break;