From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751360AbdBXPRP (ORCPT ); Fri, 24 Feb 2017 10:17:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50276 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751219AbdBXPRF (ORCPT ); Fri, 24 Feb 2017 10:17:05 -0500 Subject: Re: [Qemu-devel] kvm bug in __rmap_clear_dirty during live migration To: Chris Friesen , "Herongguang (Stephen)" , "Han, Huaitong" , "hangaohuai@huawei.com" , stable@vger.kernel.org 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> Cc: "kvm@vger.kernel.org" , "fangying1@huawei.com" , "xudong.hao@linux.intel.com" , "qemu-devel@nongnu.org" , "wangxinxin.wang@huawei.com" , "kai.huang@linux.intel.com" , "rkrcmar@redhat.com" , "guangrong.xiao@linux.intel.com" , linux-kernel@vger.kernel.org From: Paolo Bonzini Message-ID: <7fdf2551-3d55-1bd9-2848-720a880cc93e@redhat.com> Date: Fri, 24 Feb 2017 16:14:03 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <58B04CD3.7010304@windriver.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 24 Feb 2017 15:14:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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