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-rw-r--r--arch/x86/kvm/i8254.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 59ebd37ad79e..e665d1c623ca 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -603,10 +603,29 @@ void kvm_free_pit(struct kvm *kvm)
static void __inject_pit_timer_intr(struct kvm *kvm)
{
+ struct kvm_vcpu *vcpu;
+ int i;
+
mutex_lock(&kvm->lock);
kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1);
kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0);
mutex_unlock(&kvm->lock);
+
+ /*
+ * Provides NMI watchdog support via Virtual Wire mode.
+ * The route is: PIT -> PIC -> LVT0 in NMI mode.
+ *
+ * Note: Our Virtual Wire implementation is simplified, only
+ * propagating PIT interrupts to all VCPUs when they have set
+ * LVT0 to NMI delivery. Other PIC interrupts are just sent to
+ * VCPU0, and only if its LVT0 is in EXTINT mode.
+ */
+ if (kvm->arch.vapics_in_nmi_mode > 0)
+ for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+ vcpu = kvm->vcpus[i];
+ if (vcpu)
+ kvm_apic_nmi_wd_deliver(vcpu);
+ }
}
void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu)