From: Avi Kivity <avi@redhat.com>
To: "Roedel, Joerg" <Joerg.Roedel@amd.com>
Cc: Takuya Yoshikawa <takuya.yoshikawa@gmail.com>,
"mtosatti@redhat.com" <mtosatti@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"yoshikawa.takuya@oss.ntt.co.jp" <yoshikawa.takuya@oss.ntt.co.jp>
Subject: Re: [PATCH 2/3] KVM: MMU: Introduce a helper to read guest pte
Date: Wed, 20 Apr 2011 14:18:12 +0300 [thread overview]
Message-ID: <4DAEC0F4.70201@redhat.com> (raw)
In-Reply-To: <20110420110630.GZ2192@amd.com>
On 04/20/2011 02:06 PM, Roedel, Joerg wrote:
> On Wed, Apr 20, 2011 at 06:05:08AM -0400, Avi Kivity wrote:
> > On 04/20/2011 12:35 PM, Roedel, Joerg wrote:
>
> > > This patch seems only to introduce another wrapper around
> > > kvm_read_guest_page_mmu(), so I don't see a problem in this patch.
> >
> > By patch 3, ptep_user will be computed in this function and no longer
> > available for setting the accessed bit later on.
> >
> > > The kvm_read_guest_page_mmu takes care whether it gets a l1-gfn or
> > > l2-gfn (by calling mmu->translate_gpa).
> >
> > But cmpxchg_gpte() does not.
>
> You are right, cmpxchg_gpte needs to handle this too. But the bug is not
> introduced with this patch-set it was there before.
Correct. The reason I don't want the helper, is so we can use ptep_user
in both places (not for efficiency, just to make sure it's exactly the
same value).
> The cmpxchg_gpte function treats all table_gfns as l1-gfns. I'll send a
> fix soon.
Thanks.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-04-20 11:18 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-18 18:32 [PATCH 1/3] KVM: Introduce a helper to check if gfn is in memslot Takuya Yoshikawa
2011-04-18 18:34 ` [PATCH 2/3] KVM: MMU: Introduce a helper to read guest pte Takuya Yoshikawa
2011-04-20 9:07 ` Avi Kivity
2011-04-20 9:35 ` Roedel, Joerg
2011-04-20 10:05 ` Avi Kivity
2011-04-20 11:06 ` Roedel, Joerg
2011-04-20 11:18 ` Avi Kivity [this message]
2011-04-20 13:33 ` [PATCH] KVM: MMU: Make cmpxchg_gpte aware of nesting too Roedel, Joerg
2011-04-21 1:02 ` Takuya Yoshikawa
2011-04-21 8:11 ` Avi Kivity
2011-04-21 1:07 ` [PATCH 2/3] KVM: MMU: Introduce a helper to read guest pte Takuya Yoshikawa
2011-04-18 18:38 ` [RFC PATCH 3/3] KVM: MMU: Optimize guest page table walk Takuya Yoshikawa
2011-04-18 18:52 ` Joerg Roedel
2011-04-19 1:24 ` Takuya Yoshikawa
2011-04-19 6:20 ` Joerg Roedel
2011-04-19 1:42 ` Xiao Guangrong
2011-04-19 3:47 ` Takuya Yoshikawa
2011-04-20 9:09 ` Avi Kivity
2011-04-20 9:02 ` Avi Kivity
2011-04-29 2:46 ` Andi Kleen
2011-04-29 5:38 ` Takuya Yoshikawa
2011-04-29 6:30 ` Takuya Yoshikawa
2011-04-29 6:59 ` Andi Kleen
2011-04-29 13:51 ` Takuya Yoshikawa
2011-04-29 16:05 ` Andi Kleen
2011-05-01 13:32 ` Avi Kivity
2011-05-01 20:51 ` Andi Kleen
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