From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [Bug 54061] guest panic after live migration Date: Mon, 25 Feb 2013 16:26:17 +0800 Message-ID: <512B2029.1090009@linux.vnet.ibm.com> References: <20130220080616.A0DCA11FB82@bugzilla.kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: bugzilla-daemon@bugzilla.kernel.org Return-path: Received: from e28smtp04.in.ibm.com ([122.248.162.4]:49377 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754959Ab3BYI0Y (ORCPT ); Mon, 25 Feb 2013 03:26:24 -0500 Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 25 Feb 2013 13:53:45 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id EE2003940055 for ; Mon, 25 Feb 2013 13:56:18 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1P8QEfu34865348 for ; Mon, 25 Feb 2013 13:56:14 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1P8QIcD012455 for ; Mon, 25 Feb 2013 19:26:18 +1100 In-Reply-To: <20130220080616.A0DCA11FB82@bugzilla.kernel.org> Sender: kvm-owner@vger.kernel.org List-ID: On 02/20/2013 04:06 PM, bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=54061 > > > > > > --- Comment #2 from Jay Ren 2013-02-20 08:06:16 --- > Marcleo, > > yes, after reverting that commit "caf6900f2d8", live-migration can work fine. > Sorry for the wrong patch and the bug is: the fast page fault path can make large-spte writeable without probably set dirty bitmap for all small pages. Two ways to fix these: 1): covert the large-spte to small sptes and wirte-protect them, then no readonly large-spte exists. 2): only allow fast page fault to fix #PF on small spte. Seems the first way is better because the second way can cause useless page table waking.