KVM: x86: Fix and refactor NMI watchdog emulation

[safe/jmp/linux-2.6] / arch / x86 / kvm / i8254.c

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 580cc1d..b6fcf5a 100644 (file)
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -612,15 +612,18 @@ static void __inject_pit_timer_intr(struct kvm *kvm)
        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.
+        * 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.
         */
        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                vcpu = kvm->vcpus[i];
-               if (!vcpu)
-                       continue;
-               kvm_apic_local_deliver(vcpu, APIC_LVT0);
+               if (vcpu)
+                       kvm_apic_nmi_wd_deliver(vcpu);
        }
 }