From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932583AbbBZOrD (ORCPT ); Thu, 26 Feb 2015 09:47:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57354 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932280AbbBZOq7 (ORCPT ); Thu, 26 Feb 2015 09:46:59 -0500 Message-ID: <54EF31CC.6070003@redhat.com> Date: Thu, 26 Feb 2015 15:46:36 +0100 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Borislav Petkov CC: Tiejun Chen , kvm ML , lkml Subject: Re: [PATCH] KVM: SVM: fix interrupt injection (apic->isr_count always 0) References: <20150225160056.GF3226@pd.tnic> <20150225194140.GA9777@potion.brq.redhat.com> In-Reply-To: <20150225194140.GA9777@potion.brq.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/02/2015 20:41, Radim Krčmář wrote: > 2015-02-25 17:00+0100, Borislav Petkov: >> Hi, >> >> commit in $Subject breaks my kvm guest on AMD host, causing it to do the >> following below. Mouse doesn't work anymore in the guest, network is >> gone too. >> >> Reverting it fixes the issue. > > Thanks, > > this patch should fix it. > > ---8<--- > In commit b4eef9b36db4, we started to use hwapic_isr_update() != NULL > instead of kvm_apic_vid_enabled(vcpu->kvm). This didn't work because > SVM had it defined and "apicv" path in apic_{set,clear}_isr() does not > change apic->isr_count, because it should always be 1. The initial > value of apic->isr_count was based on kvm_apic_vid_enabled(vcpu->kvm), > which is always 0 for SVM, so KVM could have injected interrupts when it > shouldn't. > > Fix it by setting SVM's hwapic_isr_update to NULL and make the initial > isr_count depend on hwapic_isr_update() for good measure. > > Fixes: b4eef9b36db4 ("kvm: x86: vmx: NULL out hwapic_isr_update() in case of !enable_apicv") > Reported-by: Borislav Petkov > Signed-off-by: Radim Krčmář > --- > arch/x86/kvm/lapic.c | 4 ++-- > arch/x86/kvm/svm.c | 7 +------ > 2 files changed, 3 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index e55b5fc344eb..bd4e34de24c7 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1572,7 +1572,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu) > apic_set_reg(apic, APIC_TMR + 0x10 * i, 0); > } > apic->irr_pending = kvm_apic_vid_enabled(vcpu->kvm); > - apic->isr_count = kvm_apic_vid_enabled(vcpu->kvm); > + apic->isr_count = kvm_x86_ops->hwapic_isr_update ? 1 : 0; > apic->highest_isr_cache = -1; > update_divide_count(apic); > atomic_set(&apic->lapic_timer.pending, 0); > @@ -1782,7 +1782,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu, > update_divide_count(apic); > start_apic_timer(apic); > apic->irr_pending = true; > - apic->isr_count = kvm_apic_vid_enabled(vcpu->kvm) ? > + apic->isr_count = kvm_x86_ops->hwapic_isr_update ? > 1 : count_vectors(apic->regs + APIC_ISR); > apic->highest_isr_cache = -1; > if (kvm_x86_ops->hwapic_irr_update) > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index d319e0c24758..54c7b36ad12d 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -3649,11 +3649,6 @@ static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap) > return; > } > > -static void svm_hwapic_isr_update(struct kvm *kvm, int isr) > -{ > - return; > -} > - > static void svm_sync_pir_to_irr(struct kvm_vcpu *vcpu) > { > return; > @@ -4403,7 +4398,7 @@ static struct kvm_x86_ops svm_x86_ops = { > .set_virtual_x2apic_mode = svm_set_virtual_x2apic_mode, > .vm_has_apicv = svm_vm_has_apicv, > .load_eoi_exitmap = svm_load_eoi_exitmap, > - .hwapic_isr_update = svm_hwapic_isr_update, > + .hwapic_isr_update = NULL, Please remove the line altogether. Paolo