KVM: x86: Fix and refactor NMI watchdog emulation
This patch refactors the NMI watchdog delivery patch, consolidating
tests and providing a proper API for delivering watchdog events.
An included micro-optimization is to check only for apic_hw_enabled in
kvm_apic_local_deliver (the test for LVT mask is covering the
soft-disabled case already).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 580cc1d..b6fcf5a 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -612,15 +612,18 @@
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);
}
}