Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751993AbaLRDPV (ORCPT ); Wed, 17 Dec 2014 22:15:21 -0500 Received: from mga01.intel.com ([192.55.52.88]:35600 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751719AbaLRDPT convert rfc822-to-8bit (ORCPT ); Wed, 17 Dec 2014 22:15:19 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,598,1413270000"; d="scan'208";a="649568512" From: "Wu, Feng" To: Paolo Bonzini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "x86@kernel.org" , Gleb Natapov , "dwmw2@infradead.org" , "joro@8bytes.org" , Alex Williamson , Jiang Liu CC: "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , KVM list , Eric Auger , "Wu, Feng" Subject: RE: [v3 25/26] KVM: Suppress posted-interrupt when 'SN' is set Thread-Topic: [v3 25/26] KVM: Suppress posted-interrupt when 'SN' is set Thread-Index: AQHQGiD0lOD9GQH6kUSYRNw+5OxzD5yUq/Bg Date: Thu, 18 Dec 2014 03:14:59 +0000 Message-ID: References: <1418397300-10870-1-git-send-email-feng.wu@intel.com> <1418397300-10870-26-git-send-email-feng.wu@intel.com> <5491C0A2.7040503@redhat.com> In-Reply-To: <5491C0A2.7040503@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: linux-kernel-owner@vger.kernel.org > [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Paolo Bonzini > Sent: Thursday, December 18, 2014 1:43 AM > To: Wu, Feng; Thomas Gleixner; Ingo Molnar; H. Peter Anvin; x86@kernel.org; > Gleb Natapov; Paolo Bonzini; dwmw2@infradead.org; joro@8bytes.org; Alex > Williamson; Jiang Liu > Cc: iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org; KVM list; > Eric Auger > Subject: Re: [v3 25/26] KVM: Suppress posted-interrupt when 'SN' is set > > > > On 12/12/2014 16:14, Feng Wu wrote: > > Currently, we don't support urgent interrupt, all interrupts > > are recognized as non-urgent interrupt, so we cannot send > > posted-interrupt when 'SN' is set. > > Can this happen? If the vcpu is in guest mode, it cannot have been > scheduled out, and that's the only case when SN is set. > > Paolo Currently, the only place where SN is set is vCPU is preempted and waiting for the next scheduling in the runqueue. But I am not sure whether we need to set SN for other purpose in future. Adding SN checking here is just to follow the Spec. non-urgent interrupts are suppressed when SN is set. Thanks, Feng > > > Signed-off-by: Feng Wu > > > --- > > arch/x86/kvm/vmx.c | 11 +++++++++-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > > index a1c83a2..0aee151 100644 > > --- a/arch/x86/kvm/vmx.c > > +++ b/arch/x86/kvm/vmx.c > > @@ -4401,15 +4401,22 @@ static int vmx_vm_has_apicv(struct kvm *kvm) > > static void vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int > vector) > > { > > struct vcpu_vmx *vmx = to_vmx(vcpu); > > - int r; > > + int r, sn; > > > > if (pi_test_and_set_pir(vector, &vmx->pi_desc)) > > return; > > > > + /* > > + * Currently, we don't support urgent interrupt, all interrupts > > + * are recognized as non-urgent interrupt, so we cannot send > > + * posted-interrupt when 'SN' is set. > > + */ > > + sn = pi_test_sn(&vmx->pi_desc); > > + > > r = pi_test_and_set_on(&vmx->pi_desc); > > kvm_make_request(KVM_REQ_EVENT, vcpu); > > #ifdef CONFIG_SMP > > - if (!r && (vcpu->mode == IN_GUEST_MODE)) > > + if (!r && !sn && (vcpu->mode == IN_GUEST_MODE)) > > apic->send_IPI_mask(get_cpu_mask(vcpu->cpu), > > POSTED_INTR_VECTOR); > > else > > -- > -- > 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/ -- 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/