Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757433AbbDVNrN (ORCPT ); Wed, 22 Apr 2015 09:47:13 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:35732 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757285AbbDVNrJ (ORCPT ); Wed, 22 Apr 2015 09:47:09 -0400 Message-ID: <5537A658.5060503@redhat.com> Date: Wed, 22 Apr 2015 15:47:04 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Luis Henriques CC: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, saso.linux@astim.si, lists2009@fnarfbargle.com, Nadav Amit , stable@vger.kernel.org Subject: Re: [PATCH stable] KVM: x86: Fix lost interrupt on irr_pending race References: <1429602745-29882-1-git-send-email-pbonzini@redhat.com> <55360EA9.2030806@redhat.com> <20150422133401.GE3671@charon> In-Reply-To: <20150422133401.GE3671@charon> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1784 Lines: 54 On 22/04/2015 15:34, Luis Henriques wrote: > Thanks Paolo. I was going to apply this backport to the 3.16 kernel > but it looks like the original commit is a clean cherry-pick. Shall I > still apply your backport, or do you think the original commit should > be applied instead? Indeed you're right. I wrote the backport for 3.16(.0). However, commit 56cc2406d68c0f09505c389e276f27a99f495cbd was marked for stable, so it's necessary to cherry-pick the entire patch on the stable kernel where the buggy commit was backported. That should be, according to the stable@vger.kernel.org archives, 3.10.54+, 3.13.11.7+, 3.14.18+, 3.16.2+. Paolo > Cheers, > -- > Lu?s > >> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c >> index 6e8ce5a1a05d..e0e5642dae41 100644 >> --- a/arch/x86/kvm/lapic.c >> +++ b/arch/x86/kvm/lapic.c >> @@ -341,8 +341,12 @@ EXPORT_SYMBOL_GPL(kvm_apic_update_irr); >> >> static inline void apic_set_irr(int vec, struct kvm_lapic *apic) >> { >> - apic->irr_pending = true; >> apic_set_vector(vec, apic->regs + APIC_IRR); >> + /* >> + * irr_pending must be true if any interrupt is pending; set it after >> + * APIC_IRR to avoid race with apic_clear_irr >> + */ >> + apic->irr_pending = true; >> } >> >> static inline int apic_search_irr(struct kvm_lapic *apic) >> >> >> Thanks, >> >> Paolo >> -- >> To unsubscribe from this list: send the line "unsubscribe stable" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/