With NMI intercept moved to check_nested_events there is a race
condition where vcpu->arch.nmi_pending is set late causing
the execution of check_nested_events to not setup correctly
for nested.exit_required. A second call to check_nested_events
allows the injectable nmi to be detected in time in order to
require immediate exit from L2 to L1.
Signed-off-by: Cathy Avery <cavery@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 027dfd278a97..ecfafcd93536 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7734,10 +7734,17 @@ static int inject_pending_event(struct kvm_vcpu *vcpu)
vcpu->arch.smi_pending = false;
++vcpu->arch.smi_count;
enter_smm(vcpu);
- } else if (vcpu->arch.nmi_pending && kvm_x86_ops.nmi_allowed(vcpu)) {
- --vcpu->arch.nmi_pending;
- vcpu->arch.nmi_injected = true;
- kvm_x86_ops.set_nmi(vcpu);
+ } else if (vcpu->arch.nmi_pending) {
+ if (is_guest_mode(vcpu) && kvm_x86_ops.check_nested_events) {
+ r = kvm_x86_ops.check_nested_events(vcpu);
+ if (r != 0)
+ return r;
+ }
+ if (kvm_x86_ops.nmi_allowed(vcpu)) {
+ --vcpu->arch.nmi_pending;
+ vcpu->arch.nmi_injected = true;
+ kvm_x86_ops.set_nmi(vcpu);
+ }
} else if (kvm_cpu_has_injectable_intr(vcpu)) {
/*
* Because interrupts can be injected asynchronously, we are
--
2.20.1
