From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754874AbaIBRR7 (ORCPT ); Tue, 2 Sep 2014 13:17:59 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:44764 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754651AbaIBRR5 (ORCPT ); Tue, 2 Sep 2014 13:17:57 -0400 MIME-Version: 1.0 In-Reply-To: <5405F503.9040507@redhat.com> References: <1409308277-4021-1-git-send-email-pbonzini@redhat.com> <1409308277-4021-3-git-send-email-pbonzini@redhat.com> <5405F503.9040507@redhat.com> From: David Matlack Date: Tue, 2 Sep 2014 10:17:37 -0700 Message-ID: Subject: Re: [PATCH 2/3] kvm: fix potentially corrupt mmio cache To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, stable@vger.kernel.org, Xiao Guangrong Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 2, 2014 at 9:49 AM, Paolo Bonzini wrote: > Il 02/09/2014 18:44, David Matlack ha scritto: >> > >> > -#define MMIO_GEN_SHIFT 19 >> > -#define MMIO_GEN_LOW_SHIFT 9 >> > -#define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 1) >> > +#define MMIO_GEN_SHIFT 20 >> > +#define MMIO_GEN_LOW_SHIFT 10 >> > +#define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 2) >> > #define MMIO_GEN_MASK ((1 << MMIO_GEN_SHIFT) - 1) >> > #define MMIO_MAX_GEN ((1 << MMIO_GEN_SHIFT) - 1) >> > >> > @@ -4428,7 +4432,7 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm) >> > * The very rare case: if the generation-number is round, >> > * zap all shadow pages. >> > */ >> > - if (unlikely(kvm_current_mmio_generation(kvm) >= MMIO_MAX_GEN)) { >> > + if (unlikely(kvm_current_mmio_generation(kvm) == 0)) { >> >> This should be in patch 1/3. > > I don't think so. This change is not due to the removal of biasing in > x86.c, but rather due to removing bit 0 from MMIO_GEN_LOW_MASK. > > I placed it here, because the previous test works just fine until bit 0 > is removed from MMIO_GEN_LOW_MASK. Ah ok, you're right. > > Paolo