diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-04-11 14:53:26 -0300 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-04-27 12:04:11 +0300 |
| commit | 3d80840d96127401ba6aeadd813c3a15b84e70fe (patch) | |
| tree | b3e083c651f09fee362d88f0d1fc140194f2431d /arch/x86/kvm/irq.c | |
| parent | 3564990af1b9f77a63692c1079e9c41af229f066 (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 'arch/x86/kvm/irq.c')
| -rw-r--r-- | arch/x86/kvm/irq.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index dbfe21c99c48..ce1f583459b1 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -26,6 +26,21 @@ #include "i8254.h" /* + * check if there are pending timer events + * to be processed. + */ +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) +{ + int ret; + + ret = pit_has_pending_timer(vcpu); + ret |= apic_has_pending_timer(vcpu); + + return ret; +} +EXPORT_SYMBOL(kvm_cpu_has_pending_timer); + +/* * check if there is pending interrupt without * intack. */ |