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authorAvi Kivity <avi@qumranet.com>2008-02-25 10:28:31 +0200
committerAvi Kivity <avi@qumranet.com>2008-03-04 15:19:48 +0200
commit8c35f237fb5664d30aa90448c3d6cea0cbb43f35 (patch)
tree1de7e021aff7ac0593ed9307045f6dd4fa771995
parent0b975a3c2d53829fa978e18fabae7d99031f588f (diff)
downloadlinux-linaro-8c35f237fb5664d30aa90448c3d6cea0cbb43f35.tar.gz
KVM: Route irq 0 to vcpu 0 exclusively
Some Linux versions allow the timer interrupt to be processed by more than one cpu, leading to hangs due to tsc instability. Work around the issue by only disaptching the interrupt to vcpu 0. Problem analyzed (and patch tested) by Sheng Yang. Signed-off-by: Avi Kivity <avi@qumranet.com>
-rw-r--r--virt/kvm/ioapic.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 317f8e211cd..4232fd75dd2 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -211,6 +211,10 @@ static void ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
case IOAPIC_LOWEST_PRIORITY:
vcpu = kvm_get_lowest_prio_vcpu(ioapic->kvm, vector,
deliver_bitmask);
+#ifdef CONFIG_X86
+ if (irq == 0)
+ vcpu = ioapic->kvm->vcpus[0];
+#endif
if (vcpu != NULL)
ioapic_inj_irq(ioapic, vcpu, vector,
trig_mode, delivery_mode);
@@ -220,6 +224,10 @@ static void ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
deliver_bitmask, vector, IOAPIC_LOWEST_PRIORITY);
break;
case IOAPIC_FIXED:
+#ifdef CONFIG_X86
+ if (irq == 0)
+ deliver_bitmask = 1;
+#endif
for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
if (!(deliver_bitmask & (1 << vcpu_id)))
continue;