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From: Avi Kivity <avi@qumranet.com>
To: Joerg Rodel <joerg.roedel@amd.com>
Cc: kvm@vger.kernel.org, stable@kernel.org, Alexander Graf <agraf@suse.de>
Subject: Re: [PATCH] KVM: SVM: fix random segfaults with NPT enabled
Date: Wed, 27 Aug 2008 16:53:26 +0300	[thread overview]
Message-ID: <48B55C56.2060503@qumranet.com> (raw)
In-Reply-To: <48B55266.4000300@qumranet.com>

Avi Kivity wrote:
> Joerg Rodel wrote:
>> From: Joerg Roedel <joerg.roedel@amd.com>
>>
>> This patch introduces a guest TLB flush on every NPF exit in KVM. 
>> This fixes
>> random segfaults and #UD exceptions in the guest seen under some 
>> workloads
>> (e.g. long running compile workloads or tbench). A kernbench run with 
>> and
>> without that fix showed that it has a slowdown lower than 0.5%
>>
>>   
>
> hm.  tbench doesn't allocate memory, so there shouldn't be any npt 
> faults.  I don't see how this can make a difference.
>
> It can only change something if X is started and we're tracking writes 
> to the framebuffer.  Is this the case?
>

I fixed a missing flush in this area.  Does it help? (I doubt it).  Can 
you post instructions on how to reproduce?

-- 
error compiling committee.c: too many arguments to function


  parent reply	other threads:[~2008-08-27 13:53 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-27 12:18 [PATCH] KVM: SVM: fix random segfaults with NPT enabled Joerg Rodel
2008-08-27 13:11 ` Avi Kivity
2008-08-27 13:53   ` Joerg Rodel
2008-08-27 15:21     ` Avi Kivity
2008-08-27 15:32       ` Joerg Roedel
2008-08-27 13:53   ` Avi Kivity [this message]
2008-08-27 13:57     ` Joerg Rodel
2008-08-27 15:22       ` Avi Kivity
2008-08-27 15:35         ` Joerg Roedel
2008-08-27 15:50           ` Avi Kivity
2008-08-27 16:27             ` Joerg Rodel
2008-08-27 16:49               ` Avi Kivity
2008-08-27 16:59                 ` Avi Kivity
2008-08-28 14:58                   ` Joerg Rodel
2008-08-28 15:15                     ` Avi Kivity
2008-08-28 15:19                       ` Joerg Roedel
2008-08-28 15:47                         ` Avi Kivity
2008-08-28 15:29                       ` Avi Kivity
2008-08-28 15:58                         ` Joerg Roedel

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