From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37935) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4tBw-0006gS-GA for qemu-devel@nongnu.org; Mon, 23 May 2016 12:58:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b4tBs-0000Ee-LR for qemu-devel@nongnu.org; Mon, 23 May 2016 12:58:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50734) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4tBs-0000EV-FG for qemu-devel@nongnu.org; Mon, 23 May 2016 12:58:52 -0400 Date: Mon, 23 May 2016 21:42:23 +0530 From: Amit Shah Message-ID: <20160523161223.GE24585@grmbl.mre> References: <146239057139.11271.9011797645454781543.stgit@bahia.huguette.org> <57331E97.8050205@redhat.com> <20160511141034.0955306d@bahia.lab.toulouse-stg.fr.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160511141034.0955306d@bahia.lab.toulouse-stg.fr.ibm.com> Subject: Re: [Qemu-devel] [PATCH] migration: introduce migrate_is_blocked() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Greg Kurz Cc: Paolo Bonzini , qemu-devel@nongnu.org, Peter Maydell , "Dr. David Alan Gilbert" , Juan Quintela On (Wed) 11 May 2016 [14:10:34], Greg Kurz wrote: > On Wed, 11 May 2016 13:59:19 +0200 > Paolo Bonzini wrote: > > > On 04/05/2016 21:44, Greg Kurz wrote: > > > QEMU has currently two ways to prevent migration to occur: > > > - migration blocker when it depends on runtime state > > > - VMStateDescription.unmigratable when migration is not supported at all > > > > > > This patch gathers all the logic into a single function to be called from > > > both the savevm and the migrate paths. > > > > > > This fixes a bug with 9p, at least, where savevm would succeed and the > > > following would happen in the guest after loadvm: > > > > > > $ ls /host > > > ls: cannot access /host: Protocol error > > > > > > With this patch: > > > > > > (qemu) savevm foo > > > Migration is disabled when VirtFS export path '/' is mounted in the guest > > > using mount_tag 'host' > > > > > > Signed-off-by: Greg Kurz > > > --- > > > > > > Since there has been some activity on 9p again since a few weeks, maybe it > > > is not too late for 2.6, if everybody agrees the fix is ok ? > > > > The patch is good, but I think the subject should be > > > > savevm: fail if migration blockers are present > > > > The subject you used would be good for the include/migration and > > migration/migration.c parts alone (where you introduce the function > > without any semantic change). > > > > Yeah, I agree the subject you are suggesting is far more informative :) I'll apply this with the suggested subject. Please CC the migration maintainers for faster processing next time around. Thanks, Amit