KVM: VMX: Fix pending NMI-vs.-IRQ race for user space irqchip

As with the kernel irqchip, don't allow an NMI to stomp over an already
injected IRQ; instead wait for the IRQ injection to be completed.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e446f232588e..487e1dcdce33 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2486,7 +2486,9 @@ static void do_interrupt_requests(struct kvm_vcpu *vcpu,
         vmx_update_window_states(vcpu);
 
         if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) {
-                if (vcpu->arch.nmi_window_open) {
+                if (vcpu->arch.interrupt.pending) {
+                        enable_nmi_window(vcpu);
+                } else if (vcpu->arch.nmi_window_open) {
                         vcpu->arch.nmi_pending = false;
                         vcpu->arch.nmi_injected = true;
                 } else {