From 54aaacee35afd594bba3244c20b02cc98d80a961 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 14 May 2008 02:29:06 -0300 Subject: KVM: LAPIC: ignore pending timers if LVTT is disabled Only use the APIC pending timers count to break out of HLT emulation if the timer vector is enabled. Certain configurations of Windows simply mask out the vector without disabling the timer. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kvm/lapic.c') diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 36809d79788b..c297c50eba63 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -957,7 +957,7 @@ int apic_has_pending_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *lapic = vcpu->arch.apic; - if (lapic) + if (lapic && apic_enabled(lapic) && apic_lvt_enabled(lapic, APIC_LVTT)) return atomic_read(&lapic->timer.pending); return 0; -- cgit v1.2.2 From 06e05645661211b9eaadaf6344c335d2e80f0ba2 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Fri, 6 Jun 2008 16:37:36 -0300 Subject: KVM: close timer injection race window in __vcpu_run If a timer fires after kvm_inject_pending_timer_irqs() but before local_irq_disable() the code will enter guest mode and only inject such timer interrupt the next time an unrelated event causes an exit. It would be simpler if the timer->pending irq conversion could be done with IRQ's disabled, so that the above problem cannot happen. For now introduce a new vcpu requests bit to cancel guest entry. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/lapic.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kvm/lapic.c') diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index c297c50eba63..ebc03f5ae162 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -940,6 +940,7 @@ static int __apic_timer_fn(struct kvm_lapic *apic) wait_queue_head_t *q = &apic->vcpu->wq; atomic_inc(&apic->timer.pending); + set_bit(KVM_REQ_PENDING_TIMER, &apic->vcpu->requests); if (waitqueue_active(q)) { apic->vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; wake_up_interruptible(q); -- cgit v1.2.2