From: Paolo Bonzini <pbonzini@redhat.com>
To: David Matlack <dmatlack@google.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
stable@vger.kernel.org,
Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: Re: [PATCH 2/3] kvm: fix potentially corrupt mmio cache
Date: Tue, 02 Sep 2014 18:49:07 +0200 [thread overview]
Message-ID: <5405F503.9040507@redhat.com> (raw)
In-Reply-To: <CALzav=en9rEpJXrhinE5-jnBKB_x4oEMwY=ODtfrqKYw1oTpyQ@mail.gmail.com>
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.
Paolo
next prev parent reply other threads:[~2014-09-02 16:49 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-29 10:31 [PATCH 0/3] fix bugs with stale or corrupt MMIO caches Paolo Bonzini
2014-08-29 10:31 ` [PATCH 1/3] KVM: do not bias the generation number in kvm_current_mmio_generation Paolo Bonzini
2014-08-29 10:31 ` [PATCH 2/3] kvm: fix potentially corrupt mmio cache Paolo Bonzini
2014-09-02 16:44 ` David Matlack
2014-09-02 16:49 ` Paolo Bonzini [this message]
2014-09-02 17:17 ` David Matlack
2014-08-29 10:31 ` [PATCH 3/3] kvm: x86: fix stale mmio cache bug Paolo Bonzini
2014-09-02 15:42 ` [PATCH 0/3] fix bugs with stale or corrupt MMIO caches Paolo Bonzini
2014-09-02 16:47 ` David Matlack
2014-09-02 16:50 ` Paolo Bonzini
2014-09-02 17:18 ` David Matlack
2014-09-03 5:30 ` Xiao Guangrong
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