Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753574AbdCMO7l (ORCPT ); Mon, 13 Mar 2017 10:59:41 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:3875 "EHLO dggrg02-dlp.huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751733AbdCMO7b (ORCPT ); Mon, 13 Mar 2017 10:59:31 -0400 Subject: Re: [Qemu-devel] kvm bug in __rmap_clear_dirty during live migration To: "Huang, Kai" , "Herongguang (Stephen)" , Paolo Bonzini , "Chris Friesen" , "Han, Huaitong" , "hangaohuai@huawei.com" , References: <589C7E96.9060905@huawei.com> <589D83CE.1090803@huawei.com> <589DDC05.9010807@windriver.com> <58AA51D6.6020508@huawei.com> <1487565495.3740.27.camel@intel.com> <58AD0094.90304@windriver.com> <4dd92012-626a-2d80-9adb-0be398f73eb1@redhat.com> <58AD92AE.6040502@windriver.com> <6c5567f4-192d-aefd-90e4-89f53479c24e@redhat.com> <58AF9921.6060201@huawei.com> <58B04CD3.7010304@windriver.com> <7fdf2551-3d55-1bd9-2848-720a880cc93e@redhat.com> <58B0E191.6040108@huawei.com> <50916996-297e-a794-38e8-5c7ca9389419@linux.intel.com> CC: "kvm@vger.kernel.org" , "xudong.hao@linux.intel.com" , "qemu-devel@nongnu.org" , "wangxinxin.wang@huawei.com" , "rkrcmar@redhat.com" , "guangrong.xiao@linux.intel.com" , From: fangying Message-ID: Date: Mon, 13 Mar 2017 22:58:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <50916996-297e-a794-38e8-5c7ca9389419@linux.intel.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.177.223.127] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020204.58C6B3AD.0183,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 8c2e9744ba3f790e54dc0b40b3050c23 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1572 Lines: 61 Hi, Huang Kai After weeks of intensive testing, we think the problem is solved and this issue can be closed. On 2017/2/27 15:38, Huang, Kai wrote: > > > On 2/25/2017 2:44 PM, Herongguang (Stephen) wrote: >> >> >> On 2017/2/24 23:14, Paolo Bonzini wrote: >>> >>> >>> On 24/02/2017 16:10, Chris Friesen wrote: >>>> On 02/23/2017 08:23 PM, Herongguang (Stephen) wrote: >>>> >>>>> On 2017/2/22 22:43, Paolo Bonzini wrote: >>>> >>>>>> Hopefully Gaohuai and Rongguang can help with this too. >>>>>> >>>>>> Paolo >>>>> >>>>> Yes, we are looking into and testing this. >>>>> >>>>> I think this can result in any memory corruption, if VM1 writes its >>>>> PML buffer into VM2’s VMCS (since sched_in/sched_out notifier of VM1 >>>>> is not registered yet), then VM1 is destroyed (hence its PML buffer >>>>> is freed back to kernel), after that, VM2 starts migration, so CPU >>>>> logs VM2’s dirty GFNS into a freed memory, results in any memory >>>>> corruption. >>>>> >>>>> As its severity, this commit >>>>> (http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4e59516a12a6ef6dcb660cb3a3f70c64bd60cfec) >>>>> >>>>> >>>>> >>>>> is eligible to back port to kernel stable. >>>> >>>> Are we expecting that fix to resolve the original issue, or is it a >>>> separate issue that needs fixing in stable? >>> >>> It should be the original issue. >>> >>> Paolo >>> >>> . >>> >> Yes, I agree, though we are still testing. >> >> > Hi Stephen, > > Sorry for late reply. I was taking the whole week off last week. How's > the test going? > > Thanks, > -Kai > > . >