From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 3/3] KVM: Reset PIT irq injection logic when the PIT IRQ is unmasked Date: Sun, 4 Jan 2009 18:14:45 +0200 Message-ID: <1231085685-32201-4-git-send-email-avi@redhat.com> References: <1231085685-32201-1-git-send-email-avi@redhat.com> Cc: kvm@vger.kernel.org To: Sheng Yang , Marcelo Tosatti Return-path: Received: from mx2.redhat.com ([66.187.237.31]:47942 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752150AbZADQOu (ORCPT ); Sun, 4 Jan 2009 11:14:50 -0500 In-Reply-To: <1231085685-32201-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: While the PIT is masked the guest cannot ack the irq, so the reinject logic will never allow the interrupt to be injected. Fix by resetting the reinjection counters on unmask. Unbreaks Xen. Signed-off-by: Avi Kivity --- arch/x86/kvm/i8254.c | 15 +++++++++++++++ arch/x86/kvm/i8254.h | 1 + 2 files changed, 16 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 528daad..d78d430 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -539,6 +539,16 @@ void kvm_pit_reset(struct kvm_pit *pit) pit->pit_state.irq_ack = 1; } +static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, int mask) +{ + struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier); + + if (!mask) { + atomic_set(&pit->pit_state.pit_timer.pending, 0); + pit->pit_state.irq_ack = 1; + } +} + struct kvm_pit *kvm_create_pit(struct kvm *kvm) { struct kvm_pit *pit; @@ -588,6 +598,9 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm) kvm_pit_reset(pit); + pit->mask_notifier.func = pit_mask_notifer; + kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); + return pit; } @@ -596,6 +609,8 @@ void kvm_free_pit(struct kvm *kvm) struct hrtimer *timer; if (kvm->arch.vpit) { + kvm_unregister_irq_mask_notifier(kvm, 0, + &kvm->arch.vpit->mask_notifier); mutex_lock(&kvm->arch.vpit->pit_state.lock); timer = &kvm->arch.vpit->pit_state.pit_timer.timer; hrtimer_cancel(timer); diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h index 76959c4..6acbe4b 100644 --- a/arch/x86/kvm/i8254.h +++ b/arch/x86/kvm/i8254.h @@ -46,6 +46,7 @@ struct kvm_pit { struct kvm *kvm; struct kvm_kpit_state pit_state; int irq_source_id; + struct kvm_irq_mask_notifier mask_notifier; }; #define KVM_PIT_BASE_ADDRESS 0x40 -- 1.6.0.6