From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luis Henriques Subject: Re: [PATCH stable] KVM: x86: Fix lost interrupt on irr_pending race Date: Wed, 22 Apr 2015 14:52:42 +0100 Message-ID: <20150422135242.GG3671@charon> References: <1429602745-29882-1-git-send-email-pbonzini@redhat.com> <55360EA9.2030806@redhat.com> <20150422133401.GE3671@charon> <5537A658.5060503@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, saso.linux@astim.si, lists2009@fnarfbargle.com, Nadav Amit , stable@vger.kernel.org To: Paolo Bonzini Return-path: Content-Disposition: inline In-Reply-To: <5537A658.5060503@redhat.com> Sender: stable-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Apr 22, 2015 at 03:47:04PM +0200, Paolo Bonzini wrote: >=20 >=20 > On 22/04/2015 15:34, Luis Henriques wrote: > > Thanks Paolo. I was going to apply this backport to the 3.16 kerne= l > > but it looks like the original commit is a clean cherry-pick. Shal= l I > > still apply your backport, or do you think the original commit shou= ld > > be applied instead? >=20 > 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 kerne= l > where the buggy commit was backported. >=20 > That should be, according to the stable@vger.kernel.org archives, > 3.10.54+, 3.13.11.7+, 3.14.18+, 3.16.2+. >=20 Great, thanks for the quick reply. I'll queue the (entire) fix for the 3.16 kernel. Cheers, -- Lu=EDs > Paolo >=20 > > Cheers, > > -- > > Lu=EDs > >=20 > >> 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); > >> =20 > >> static inline void apic_set_irr(int vec, struct kvm_lapic *apic) > >> { > >> - apic->irr_pending =3D 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 =3D true; > >> } > >> =20 > >> 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 stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html