From: Marcelo Tosatti <mtosatti@redhat.com>
To: Alexander Graf <agraf@suse.de>
Cc: Avi Kivity <avi@redhat.com>, kvm@vger.kernel.org
Subject: Re: [PATCH 0/5] Fix some mmu/emulator atomicity issues (v2)
Date: Tue, 16 Mar 2010 16:33:29 -0300 [thread overview]
Message-ID: <20100316193329.GA13101@amt.cnet> (raw)
In-Reply-To: <17398A15-DD8E-469C-BFFA-97AECADB3328@suse.de>
On Tue, Mar 16, 2010 at 07:22:55PM +0100, Alexander Graf wrote:
>
> On 16.03.2010, at 17:36, Marcelo Tosatti wrote:
>
> > On Mon, Mar 15, 2010 at 01:59:52PM +0200, Avi Kivity wrote:
> >> Currently when we emulate a locked operation into a shadowed guest page
> >> table, we perform a write rather than a true atomic. This is indicated
> >> by the "emulating exchange as write" message that shows up in dmesg.
> >>
> >> In addition, the pte prefetch operation during invlpg suffered from a
> >> race. This was fixed by removing the operation.
> >>
> >> This patchset fixes both issues and reinstates pte prefetch on invlpg.
> >>
> >> v3:
> >> - rebase against next branch (resolves conflicts via hypercall patch)
> >>
> >> v2:
> >> - fix truncated description for patch 1
> >> - add new patch 4, which fixes a bug in patch 5
> >
> > Applied, thanks.
>
> How relevant is this for -stable? Races don't sound good to me :)
The race mentioned above is not existant on -stable since prefetch is
disabled for invlpg.
The atomic fixes seem like a candidate, since lack of them can trigger
pagetable corruption. Avi?
next prev parent reply other threads:[~2010-03-16 19:34 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-15 11:59 [PATCH 0/5] Fix some mmu/emulator atomicity issues (v2) Avi Kivity
2010-03-15 11:59 ` [PATCH 1/5] KVM: MMU: Consolidate two guest pte reads in kvm_mmu_pte_write() Avi Kivity
2010-03-15 11:59 ` [PATCH 2/5] KVM: Make locked operations truly atomic Avi Kivity
2010-03-17 7:45 ` Jan Kiszka
2010-03-17 8:05 ` Avi Kivity
2010-03-20 9:14 ` [PATCH] KVM: x86: Fix 32-bit build breakage due to typo Jan Kiszka
2010-03-21 14:34 ` Avi Kivity
2010-03-15 11:59 ` [PATCH 3/5] KVM: Don't follow an atomic operation by a non-atomic one Avi Kivity
2010-03-15 11:59 ` [PATCH 4/5] KVM: MMU: Do not instantiate nontrapping spte on unsync page Avi Kivity
2010-03-15 11:59 ` [PATCH 5/5] KVM: MMU: Reinstate pte prefetch on invlpg Avi Kivity
2010-03-16 16:36 ` [PATCH 0/5] Fix some mmu/emulator atomicity issues (v2) Marcelo Tosatti
2010-03-16 18:22 ` Alexander Graf
2010-03-16 19:33 ` Marcelo Tosatti [this message]
2010-03-17 3:58 ` Avi Kivity
-- strict thread matches above, loose matches on Subject: below --
2010-03-10 14:50 Avi Kivity
2010-03-14 7:03 ` Avi Kivity
2010-03-15 10:16 ` Marcelo Tosatti
2010-03-15 11:52 ` Avi Kivity
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