KVM: x86: properly update ready_for_interrupt_injection

The recent changes to emulate string instructions without entering guest
mode exposed a bug where pending interrupts are not properly reflected
in ready_for_interrupt_injection.

The result is that userspace overwrites a previously queued interrupt,
when irqchip's are emulated in userspace.

Fix by always updating state before returning to userspace.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/x86.c

@@ -4653,7 +4653,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 	}
 
 	srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
-	post_kvm_run_save(vcpu);
 
 	vapic_exit(vcpu);
 
@@ -4703,6 +4702,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	r = __vcpu_run(vcpu);
 
 out:
+	post_kvm_run_save(vcpu);
 	if (vcpu->sigset_active)
 		sigprocmask(SIG_SETMASK, &sigsaved, NULL);