From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36929) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a9RjH-0005oL-3X for qemu-devel@nongnu.org; Thu, 17 Dec 2015 01:07:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a9RjC-0003su-4F for qemu-devel@nongnu.org; Thu, 17 Dec 2015 01:07:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54222) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a9RjB-0003sD-VD for qemu-devel@nongnu.org; Thu, 17 Dec 2015 01:07:50 -0500 Date: Thu, 17 Dec 2015 11:37:43 +0530 From: Amit Shah Message-ID: <20151217060743.GA6747@grmbl.mre> References: <565FF018.9040206@cn.fujitsu.com> <87egf3lqw5.fsf@emacs.mitica> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [TCG only][Migration Bug? ] Occasionally, the content of VM's memory is inconsistent between Source and Destination of migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Li, Liang Z" Cc: zhanghailiang , Li Zhijian , "quintela@redhat.com" , "qemu-devel@nongnu.org" , "Dr. David Alan Gilbert (git)" , "david@gibson.dropbear.id.au" On (Fri) 04 Dec 2015 [01:43:07], Li, Liang Z wrote: > > > > Thanks for describing how to reproduce the bug. > > If some pages are not transferred to destination then it is a bug, so we need > > to know what the problem is, notice that the problem can be that TCG is not > > marking dirty some page, that Migration code "forgets" about that page, or > > anything eles altogether, that is what we need to find. > > > > There are more posibilities, I am not sure that memtest is on 32bit mode, and > > it is inside posibility that we are missing some state when we are on real > > mode. > > > > Will try to take a look at this. > > > > THanks, again. > > > > Hi Juan & Amit > > Do you think we should add a mechanism to check the data integrity during LM like Zhijian's patch did? it may be very helpful for developers. > Actually, I did the similar thing before in order to make sure that I did the right thing we I change the code related to LM. If you mean for debugging, something that's not always on, then I'm fine with it. A script that goes along that shows the result of comparison of the diff will be helpful too, something that shows how many pages are differnt, how many bytes in a page on average, and so on. Amit