From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] If interrupt injection is not possible do not scan IRR. Date: Tue, 19 May 2009 12:50:10 +0300 Message-ID: <4A1280D2.7060508@redhat.com> References: <1242636246-11547-2-git-send-email-gleb@redhat.com> <20090518111649.GA14536@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx2.redhat.com ([66.187.237.31]:60750 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751179AbZESJuK (ORCPT ); Tue, 19 May 2009 05:50:10 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n4J9oCTl029906 for ; Tue, 19 May 2009 05:50:12 -0400 In-Reply-To: <20090518111649.GA14536@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Gleb Natapov wrote: > Forget to remove debug output before submitting. Resending. > > Signed-off-by: Gleb Natapov > diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c > index 1ccb50c..d32ceac 100644 > --- a/arch/x86/kvm/i8259.c > +++ b/arch/x86/kvm/i8259.c > @@ -218,6 +218,11 @@ int kvm_pic_read_irq(struct kvm *kvm) > struct kvm_pic *s = pic_irqchip(kvm); > > pic_lock(s); > + if (!s->output) { > + pic_unlock(s); > + return -1; > + } > + s->output = 0; > irq = pic_get_irq(&s->pics[0]); > if (irq >= 0) { > pic_intack(&s->pics[0], irq); > diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c > index 96dfbb6..e93405a 100644 > --- a/arch/x86/kvm/irq.c > +++ b/arch/x86/kvm/irq.c > @@ -78,7 +78,6 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v) > if (vector == -1) { > if (kvm_apic_accept_pic_intr(v)) { > s = pic_irqchip(v->kvm); > - s->output = 0; /* PIC */ > vector = kvm_pic_read_irq(v->kvm); > } > } > Please split into a different patch. Even though it is a lot simpler, it contains non-local changes and is therefore relatively dangerous. > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 44e87a5..854e8c9 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3174,10 +3174,10 @@ static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) > vcpu->arch.nmi_injected = true; > kvm_x86_ops->set_nmi(vcpu); > } > - } else if (kvm_cpu_has_interrupt(vcpu)) { > - if (kvm_x86_ops->interrupt_allowed(vcpu)) { > - kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu), > - false); > + } else if (kvm_x86_ops->interrupt_allowed(vcpu)) { > + int vec = kvm_cpu_get_interrupt(vcpu); > + if (vec != -1) { > + kvm_queue_interrupt(vcpu, vec, false); > kvm_x86_ops->set_irq(vcpu); > } > } > Again, I don't think this is a win. Usually ->interrupts_allowed() == true so we'll execute the rest anyway. Perhaps we could move the call to has_interrupt into get_interrupt. -- error compiling committee.c: too many arguments to function