From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55998) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5BiJ-0007u6-NK for qemu-devel@nongnu.org; Wed, 17 Jun 2015 07:41:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5BiE-0004XB-I1 for qemu-devel@nongnu.org; Wed, 17 Jun 2015 07:41:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53608) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5BiE-0004X5-9Z for qemu-devel@nongnu.org; Wed, 17 Jun 2015 07:40:58 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id E65692CAB3F for ; Wed, 17 Jun 2015 11:40:57 +0000 (UTC) Date: Wed, 17 Jun 2015 12:40:53 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20150617114053.GG2122@work-vm> References: <1434480849-23093-1-git-send-email-dgilbert@redhat.com> <558124BD.8010807@redhat.com> <20150617094829-mutt-send-email-mst@redhat.com> <55812BC4.3000600@redhat.com> <20150617121148-mutt-send-email-mst@redhat.com> <55815B06.5030508@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55815B06.5030508@redhat.com> Subject: Re: [Qemu-devel] [PATCH] Migration compatibility for serial List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: amit.shah@redhat.com, quintela@redhat.com, qemu-devel@nongnu.org, "Michael S. Tsirkin" * Paolo Bonzini (pbonzini@redhat.com) wrote: > > > On 17/06/2015 12:13, Michael S. Tsirkin wrote: > > On Wed, Jun 17, 2015 at 10:11:48AM +0200, Paolo Bonzini wrote: > >> > >> > >> On 17/06/2015 09:52, Michael S. Tsirkin wrote: > >>>> No, please. Upstream QEMU doesn't want to get into judgement about when > >>>> migration quality might be "good enough" that you can drop subsections. > >>>> It's one thing to perfect the .needed functions to make the appearance > >>>> of subsections as unlikely as possible, but adding flags is not > >>>> something we've done so far---and not something at least *I* want to do. > >>> > >>> Not like this, sure. But e.g. patches that force specific fields to > >>> behave in a way consistent with QEMU 2.2, with appropriate > >>> doducmentation would be ok I think. > >> > >> That's not what 2.2 means in "pc-i440fx-2.2". It means "same hardware > >> as 2.2", not "bug-compatible with 2.2". > >> > >> Refining the .needed functions (e.g. see commit bfa7362889) is just > >> that: describing when a subsection is needed. Forcing specific fields > >> to behave in a way consistent with QEMU 2.2 is bug compatibility. > > > > We do bug-compatible if it's not a big pain, too. > > Where, in the specific case of migration? > > Like Juan, I see where you're coming from. But it's a slippery slope, > and upstream chose not to go down it. Whatever choice upstream may have made, that was a long time ago and doesn't mean it can't change. Dave > > Paolo -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK