From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:54998) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RDA6D-0001QK-Hx for qemu-devel@nongnu.org; Mon, 10 Oct 2011 03:16:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RDA69-00067G-9V for qemu-devel@nongnu.org; Mon, 10 Oct 2011 03:16:33 -0400 Received: from [222.73.24.84] (port=56839 helo=song.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RDA68-00066y-OS for qemu-devel@nongnu.org; Mon, 10 Oct 2011 03:16:29 -0400 Message-ID: <4E929BFC.20406@cn.fujitsu.com> Date: Mon, 10 Oct 2011 15:17:16 +0800 From: Wen Congyang MIME-Version: 1.0 References: <4E8ECA91.8040409@cn.fujitsu.com> <4E8ED167.1000705@siemens.com> <20111008151622.GA17181@amd.home.annexia.org> <4E916035.5050906@web.de> <20111009102338.GN16799@amd.home.annexia.org> <4E92568E.2010507@cn.fujitsu.com> <4E929618.4040403@web.de> <4E9297CB.8010303@cn.fujitsu.com> <4E929848.6030105@web.de> In-Reply-To: <4E929848.6030105@web.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [Question] dump memory when host pci device is used by guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Luiz Capitulino , "Richard W.M. Jones" , qemu-devel At 10/10/2011 03:01 PM, Jan Kiszka Write: > On 2011-10-10 08:59, Wen Congyang wrote: >> At 10/10/2011 02:52 PM, Jan Kiszka Write: >>> On 2011-10-10 04:21, Wen Congyang wrote: >>>> At 10/09/2011 06:23 PM, Richard W.M. Jones Write: >>>>> On Sun, Oct 09, 2011 at 10:49:57AM +0200, Jan Kiszka wrote: >>>>>> As explained in the other replies: It is way more future-proof to us= e an >>>>>> interface for this which was designed for it (remote gdb) instead of >>>>>> artificially relaxing reasonable constraints of the migration mechan= ism >>>>>> plus having to follow that format with the post-processing tool. >>>>> >>>>> Any interface that isn't "get this information off my production >>>>> server *now*" so that I can get the server restarted, and send it to >>>>> an expert to analyse -- is a poor interface, whether it was designed >>>>> like that or not. Perhaps we don't have the right interface at all, >>>>> but remote gdb is not it. >>>> >>>> What about the following idea? >>>> >>>> Introduce a new monitor command named dump, and this command accepts a= filename. >>>> We can use almost all migration's code. We use this command to dump gu= est's >>>> memory, so there is no need to check whether the guest has a unmigrata= ble device. >>> >>> I do not want to reject this proposal categorically, but I would like to >>> see the gdb path fail /wrt essential requirements first. So far I don't >>> see it would. >> >> =91gdb path fail /wrt essential requirements=92 >> >> what does it mean? >=20 > That you explain why reading reading memory and processor states via the > remote gdb interface and dumping it into a proper core file cannot be > made working for you. First, I think crash can not analyze such core file. But it is not very imp= ortant. What is remote gdb interface? Do you mean that: the supporter uses gdb from= another machine to connect to customer's machine and get the data? If so, this way can not = be used when the customer needs to dump the guest's memory automatically when = watchdog timeouts. Thanks Wen Congyang >=20 > Jan >=20