path: root/virt
diff options
authorMarcelo Tosatti <mtosatti@redhat.com>2008-04-11 14:53:26 -0300
committerAvi Kivity <avi@qumranet.com>2008-04-27 12:04:11 +0300
commit3d80840d96127401ba6aeadd813c3a15b84e70fe (patch)
treeb3e083c651f09fee362d88f0d1fc140194f2431d /virt
parent3564990af1b9f77a63692c1079e9c41af229f066 (diff)
KVM: hlt emulation should take in-kernel APIC/PIT timers into account
Timers that fire between guest hlt and vcpu_block's add_wait_queue() are ignored, possibly resulting in hangs. Also make sure that atomic_inc and waitqueue_active tests happen in the specified order, otherwise the following race is open: CPU0 CPU1 if (waitqueue_active(wq)) add_wait_queue() if (!atomic_read(pit_timer->pending)) schedule() atomic_inc(pit_timer->pending) Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'virt')
1 files changed, 1 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d5911d9895c3..47cbc6e3fafd 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -765,6 +765,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
* We will block until either an interrupt or a signal wakes us up
while (!kvm_cpu_has_interrupt(vcpu)
+ && !kvm_cpu_has_pending_timer(vcpu)
&& !signal_pending(current)
&& !kvm_arch_vcpu_runnable(vcpu)) {

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