From: Avi Kivity <avi@redhat.com>
To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
KVM list <kvm@vger.kernel.org>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH 1/4] KVM: MMU: fix forgot reserved bits check in speculative path
Date: Wed, 14 Jul 2010 17:27:21 +0300 [thread overview]
Message-ID: <4C3DC949.8040801@redhat.com> (raw)
In-Reply-To: <4C3DBA97.40908@cn.fujitsu.com>
On 07/14/2010 04:24 PM, Xiao Guangrong wrote:
>
> Avi Kivity wrote:
>
>
>>> +
>>> + if (!!is_pae(vcpu) != sp->role.cr4_pae ||
>>> + is_nx(vcpu) != sp->role.nxe)
>>> + continue;
>>> +
>>>
>>>
>> Do we also need to check cr0.wp? I think so.
>>
> I think it's not too bad since we just decrease the access right, for example,
> we mark the mapping readonly for cr0.wp=0's page, the later write-access will
> cause #PF, and the read-access is OK.
>
If current cr0.wp=0 and sp->role.cr0_wp=1, that's fine, but the other
way round can relax permissions too much, marking a kernel page writeable.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
prev parent reply other threads:[~2010-07-14 14:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-13 9:42 [PATCH 1/4] KVM: MMU: fix forgot reserved bits check in speculative path Xiao Guangrong
2010-07-13 9:43 ` [PATCH 2/4] KVM: MMU: cleanup spte update path Xiao Guangrong
2010-07-13 9:45 ` [PATCH 3/4] KVM: MMU: track dirty page in speculative path properly Xiao Guangrong
2010-07-13 22:05 ` Marcelo Tosatti
2010-07-14 1:24 ` Xiao Guangrong
2010-07-14 11:09 ` Marcelo Tosatti
2010-07-14 13:18 ` Xiao Guangrong
2010-07-14 14:06 ` Marcelo Tosatti
2010-07-14 14:25 ` Avi Kivity
2010-07-15 7:44 ` Xiao Guangrong
2010-07-15 16:40 ` Marcelo Tosatti
2010-07-16 1:58 ` Xiao Guangrong
2010-07-14 5:53 ` Xiao Guangrong
2010-07-13 9:46 ` [PATCH 4/4] KVM: MMU: remove valueless output message Xiao Guangrong
2010-07-13 21:28 ` [PATCH 1/4] KVM: MMU: fix forgot reserved bits check in speculative path Marcelo Tosatti
2010-07-14 1:08 ` Xiao Guangrong
2010-07-14 13:06 ` Avi Kivity
2010-07-14 13:24 ` Xiao Guangrong
2010-07-14 14:27 ` Avi Kivity [this message]
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