From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53706) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5Bb7-0004ph-4T for qemu-devel@nongnu.org; Wed, 17 Jun 2015 07:33:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5Bb2-0001IP-2M for qemu-devel@nongnu.org; Wed, 17 Jun 2015 07:33:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36395) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5Bb1-0001IH-T9 for qemu-devel@nongnu.org; Wed, 17 Jun 2015 07:33:31 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 41E95374A10 for ; Wed, 17 Jun 2015 11:33:31 +0000 (UTC) Message-ID: <55815B06.5030508@redhat.com> Date: Wed, 17 Jun 2015 13:33:26 +0200 From: Paolo Bonzini MIME-Version: 1.0 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> In-Reply-To: <20150617121148-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] Migration compatibility for serial List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: amit.shah@redhat.com, qemu-devel@nongnu.org, "Dr. David Alan Gilbert (git)" , quintela@redhat.com 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 subsectio= ns. >>>> It's one thing to perfect the .needed functions to make the appeara= nce >>>> 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. >=20 > 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. Paolo