From 3d80840d96127401ba6aeadd813c3a15b84e70fe Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Fri, 11 Apr 2008 14:53:26 -0300 Subject: 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 Signed-off-by: Avi Kivity --- include/linux/kvm_host.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bd0c2d2d840..0bc400387ca 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -269,6 +269,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm); int kvm_cpu_get_interrupt(struct kvm_vcpu *v); int kvm_cpu_has_interrupt(struct kvm_vcpu *v); +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu); void kvm_vcpu_kick(struct kvm_vcpu *vcpu); static inline void kvm_guest_enter(void) -- cgit v1.2.3