Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761019Ab2EQH2q (ORCPT ); Thu, 17 May 2012 03:28:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8845 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757932Ab2EQH2p (ORCPT ); Thu, 17 May 2012 03:28:45 -0400 Date: Thu, 17 May 2012 10:28:41 +0300 From: Gleb Natapov To: "Michael S. Tsirkin" Cc: Marcelo Tosatti , x86@kernel.org, kvm@vger.kernel.org, Ingo Molnar , "H. Peter Anvin" , Avi Kivity , Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: [PATCHv4 3/5] kvm: host side for eoi optimization Message-ID: <20120517072841.GW32036@redhat.com> References: <42ba7beaa25855997e02fea91a11c9224c51720e.1337168687.git.mst@redhat.com> <20120516154940.GA20549@amt.cnet> <20120516162247.GA10676@redhat.com> <20120516172058.GA22861@amt.cnet> <20120516175856.GD10769@redhat.com> <20120516181500.GA23791@amt.cnet> <20120516182520.GH28798@redhat.com> <20120516182948.GF10769@redhat.com> <20120516183822.GI28798@redhat.com> <20120516190757.GA12113@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120516190757.GA12113@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1657 Lines: 48 On Wed, May 16, 2012 at 10:07:58PM +0300, Michael S. Tsirkin wrote: > > This code is reached from kvm_cpu_get_interrupt(), but this function will > > not be called in above scenario. > > I think I see. So this shall fix it also makes code cleaner > (no -2 hack). Right? kvm_apic_has_interrupt is called correct? > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index b4f7013..5a38e34 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1273,8 +1273,12 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu) > highest_irr = apic_find_highest_irr(apic); > if (highest_irr == -1) > return -1; > - if (((highest_irr & 0xF0) <= apic_get_reg(apic, APIC_PROCPRI))) > - return -2; > + /* Detect interrupt nesting and disable EOI optimization */ > + if ((highest_irr & 0xF0) <= apic_get_reg(apic, APIC_PROCPRI)) { > + if (pv_eoi_enabled(vcpu)) > + pv_eoi_clr_pending(vcpu); > + return -1; > + } > return highest_irr; > } > I do not like it. kvm_apic_has_interrupt() does not suppose to mutate state. > @@ -1306,10 +1310,6 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) > int vector = kvm_apic_has_interrupt(vcpu); > struct kvm_lapic *apic = vcpu->arch.apic; > > - /* Detect interrupt nesting and disable EOI optimization */ > - if (pv_eoi_enabled(vcpu) && vector == -2) > - pv_eoi_clr_pending(vcpu); > - > if (vector < 0) > return -1; > -- Gleb. -- 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/