1 files changed, 15 insertions, 0 deletions

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 59ebd37ad79e..580cc1d01c7d 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -603,10 +603,25 @@ 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 in IOAPIC mode.
+         * The route is: PIT -> PIC -> LVT0 in NMI mode,
+         * timer IRQs will continue to flow through the IOAPIC.
+         */
+        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+                vcpu = kvm->vcpus[i];
+                if (!vcpu)
+                        continue;
+                kvm_apic_local_deliver(vcpu, APIC_LVT0);
+        }
 }
 
 void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu)