From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52398) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cWLQD-0007zb-JM for qemu-devel@nongnu.org; Wed, 25 Jan 2017 06:07:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cWLQ9-0005wM-55 for qemu-devel@nongnu.org; Wed, 25 Jan 2017 06:07:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59428) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cWLQ8-0005wC-Uu for qemu-devel@nongnu.org; Wed, 25 Jan 2017 06:07:21 -0500 Date: Wed, 25 Jan 2017 11:07:15 +0000 From: "Daniel P. Berrange" Message-ID: <20170125110715.GB15529@redhat.com> Reply-To: "Daniel P. Berrange" References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] migration: QEMU aborts migration of "none" machine List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: Ashijeet Acharya , Juan Quintela , "dgilbert@redhat.com" , QEMU Developers On Wed, Jan 25, 2017 at 11:53:06AM +0100, Thomas Huth wrote: > On 25.01.2017 11:01, Ashijeet Acharya wrote: > > Hi Thomas, > > > > I was able to reproduce the bug you encountered while trying to migrate > > a "none" machine. > > > > After digging deep and debugging the problem with gdb, I found that > > bitmap_new() is the function that crashes qemu as it always has > > zero bits being passed to it. > > > > I had a discussion with Dave on the IRC yesterday and he suggested the > > reason of crash being the absence of RAM ( since machine is "none") > > while attempting the migration. > > > > I am not sure what the ideal solution will be in this case; Do any of > > the maintainers have any suggestions or even a starting point which I > > can ponder upon? > > I'm not that familiar with the migration code either, but maybe you > could simply check for last_ram_offset() == 0 at the beginning of > ram_save_setup() and return with an error in that case? Do we actually need/want migration to succeed when RAM is 0 or vCPU count is 0 ? If not, then we could just register a migration blocker during machine init Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|