From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Lieven Subject: Re: race between kvm-kmod-3.0 and kvm-kmod-3.3 // was: race condition in qemu-kvm-1.0.1 Date: Thu, 05 Jul 2012 01:12:18 +0200 Message-ID: <4FF4CDD2.1090101@dlhnet.de> References: <4FEB2945.1030607@dlhnet.de> <4FEB3AC6.6010206@web.de> <4FEC1FC9.7050103@dlhnet.de> <4FEC2210.1030005@siemens.com> <4FEC2475.4030202@dlhnet.de> <4FEC2626.90402@dlhnet.de> <4FF1B8A6.2020101@redhat.com> <4FF2ED2A.7080300@dlhnet.de> <4FF2EFE0.2090400@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Jan Kiszka , Gleb Natapov , qemu-devel@nongnu.org, kvm@vger.kernel.org, xiaoguangrong@cn.fujitsu.com To: Avi Kivity Return-path: In-Reply-To: <4FF2EFE0.2090400@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On 07/03/12 15:13, Avi Kivity wrote: > On 07/03/2012 04:01 PM, Peter Lieven wrote: >> Further output from my testing. >> >> Working: >> Linux 2.6.38 with included kvm module >> Linux 3.0.0 with included kvm module >> >> Not-Working: >> Linux 3.2.0 with included kvm module >> Linux 2.6.28 with kvm-kmod 3.4 >> Linux 3.0.0 with kvm-kmod 3.4 >> Linux 3.2.0 with kvm-kmod 3.4 >> >> I can trigger the race with any of qemu-kvm 0.12.5, 1.0 or 1.0.1. >> It might be that the code was introduced somewhere between 3.0.0 >> and 3.2.0 in the kvm kernel module and that the flaw is not >> in qemu-kvm. >> >> Any hints? >> > A bisect could tell us where the problem is. > > To avoid bisecting all of linux, try > > git bisect v3.2 v3.0 virt/kvm arch/x86/kvm here we go: commit ca7d58f375c650cf36900cb1da1ca2cc99b13393 Author: Xiao Guangrong Date: Wed Jul 13 14:31:08 2011 +0800 KVM: x86: fix broken read emulation spans a page boundary From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40725) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SmYkB-0002m4-QD for qemu-devel@nongnu.org; Wed, 04 Jul 2012 19:12:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SmYk9-0001kH-Vt for qemu-devel@nongnu.org; Wed, 04 Jul 2012 19:12:23 -0400 Received: from ssl.dlhnet.de ([91.198.192.8]:48651 helo=ssl.dlh.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SmYk9-0001k8-PI for qemu-devel@nongnu.org; Wed, 04 Jul 2012 19:12:21 -0400 Message-ID: <4FF4CDD2.1090101@dlhnet.de> Date: Thu, 05 Jul 2012 01:12:18 +0200 From: Peter Lieven MIME-Version: 1.0 References: <4FEB2945.1030607@dlhnet.de> <4FEB3AC6.6010206@web.de> <4FEC1FC9.7050103@dlhnet.de> <4FEC2210.1030005@siemens.com> <4FEC2475.4030202@dlhnet.de> <4FEC2626.90402@dlhnet.de> <4FF1B8A6.2020101@redhat.com> <4FF2ED2A.7080300@dlhnet.de> <4FF2EFE0.2090400@redhat.com> In-Reply-To: <4FF2EFE0.2090400@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] race between kvm-kmod-3.0 and kvm-kmod-3.3 // was: race condition in qemu-kvm-1.0.1 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Jan Kiszka , Gleb Natapov , qemu-devel@nongnu.org, kvm@vger.kernel.org, xiaoguangrong@cn.fujitsu.com On 07/03/12 15:13, Avi Kivity wrote: > On 07/03/2012 04:01 PM, Peter Lieven wrote: >> Further output from my testing. >> >> Working: >> Linux 2.6.38 with included kvm module >> Linux 3.0.0 with included kvm module >> >> Not-Working: >> Linux 3.2.0 with included kvm module >> Linux 2.6.28 with kvm-kmod 3.4 >> Linux 3.0.0 with kvm-kmod 3.4 >> Linux 3.2.0 with kvm-kmod 3.4 >> >> I can trigger the race with any of qemu-kvm 0.12.5, 1.0 or 1.0.1. >> It might be that the code was introduced somewhere between 3.0.0 >> and 3.2.0 in the kvm kernel module and that the flaw is not >> in qemu-kvm. >> >> Any hints? >> > A bisect could tell us where the problem is. > > To avoid bisecting all of linux, try > > git bisect v3.2 v3.0 virt/kvm arch/x86/kvm here we go: commit ca7d58f375c650cf36900cb1da1ca2cc99b13393 Author: Xiao Guangrong Date: Wed Jul 13 14:31:08 2011 +0800 KVM: x86: fix broken read emulation spans a page boundary