From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751690AbdB0HmG (ORCPT ); Mon, 27 Feb 2017 02:42:06 -0500 Received: from mga02.intel.com ([134.134.136.20]:54987 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484AbdB0HmE (ORCPT ); Mon, 27 Feb 2017 02:42:04 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,213,1484035200"; d="scan'208";a="69939371" Subject: Re: [Qemu-devel] kvm bug in __rmap_clear_dirty during live migration To: "Herongguang (Stephen)" , Paolo Bonzini , Chris Friesen , "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> <7fdf2551-3d55-1bd9-2848-720a880cc93e@redhat.com> <58B0E191.6040108@huawei.com> Cc: "kvm@vger.kernel.org" , "fangying1@huawei.com" , "xudong.hao@linux.intel.com" , "qemu-devel@nongnu.org" , "wangxinxin.wang@huawei.com" , "rkrcmar@redhat.com" , "guangrong.xiao@linux.intel.com" , linux-kernel@vger.kernel.org From: "Huang, Kai" Message-ID: <50916996-297e-a794-38e8-5c7ca9389419@linux.intel.com> Date: Mon, 27 Feb 2017 20:38:27 +1300 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <58B0E191.6040108@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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