From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41350) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5IKp-0001D6-GT for qemu-devel@nongnu.org; Wed, 17 Jun 2015 14:45:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5IKl-0001O1-9K for qemu-devel@nongnu.org; Wed, 17 Jun 2015 14:45:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51432) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5IKl-0001Nw-47 for qemu-devel@nongnu.org; Wed, 17 Jun 2015 14:45:11 -0400 Date: Wed, 17 Jun 2015 20:45:06 +0200 From: "Michael S. Tsirkin" Message-ID: <20150617204424-mutt-send-email-mst@redhat.com> References: <1434117956-4929-1-git-send-email-dslutz@verizon.com> <20150617160826-mutt-send-email-mst@redhat.com> <558180A0.8040708@redhat.com> <20150617161716-mutt-send-email-mst@redhat.com> <558183C1.3010402@redhat.com> <20150617162836-mutt-send-email-mst@redhat.com> <55819D8F.3000003@redhat.com> <20150617182322-mutt-send-email-mst@redhat.com> <5581A844.9090203@Gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5581A844.9090203@Gmail.com> Subject: Re: [Qemu-devel] [PATCH v7 0/9] Add limited support of VMware's hyper-call rpc List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Don Slutz Cc: qemu-devel@nongnu.org, Markus Armbruster , Don Slutz , Luiz Capitulino , Anthony Liguori , Paolo Bonzini , Andreas =?iso-8859-1?Q?F=E4rber?= , Richard Henderson On Wed, Jun 17, 2015 at 01:03:00PM -0400, Don Slutz wrote: > On 06/17/15 12:29, Michael S. Tsirkin wrote: > > On Wed, Jun 17, 2015 at 06:17:19PM +0200, Paolo Bonzini wrote: > >> > >> > >> On 17/06/2015 16:29, Michael S. Tsirkin wrote: > >>> On Wed, Jun 17, 2015 at 04:27:13PM +0200, Paolo Bonzini wrote: > >>>> > >>>> > >>>> On 17/06/2015 16:18, Michael S. Tsirkin wrote: > >>>>>>> Yes, that's what was done for parallel and pcspk as well. There's no > >>>>>>> infrastructure to avoid it. > >>>>>>> > >>>>>>> Paolo > >>>>> How do you mean? We have multiple ways to keep devices > >>>>> compatible with old versions. > >>>>> Set a new property to skip the extra stuff. > >>>> > >>>> Not if the device didn't have a vmstate at all, unfortunately. > >>> > >>> Skip creating the device completely for old machine types. > >> > >> Which device? The vmstate is tied to the same device that has always > >> been created. > > > > Just disable the new functionality. Make it behave in > > a compatible way. > > > >> we enable this thing by default (why do we?) > > > > Sigh. There is a very simple way to add a device in qemu: let user > > request it with -device. If one does this, one gets to maintain the > > resulting mess without bothering with pc maintainers in any way. > > > > But of course, everyone implementing a new feature feels it's such a > > great thing, and completel zero risk, it must be part of the default > > machine. Guess what, one then gets to bother with versioning from day 0. > > > >>>>> this seems like a big deal ... > >>>> > >>>> The PC speaker device is also enabled by default. > >>> > >>> This is historical, isn't it? > >> > >> Yes, but it has broken 2.3->2.2 migration. > >> > >> Let's just stop fighting windmills. > >> > >> Paolo > > > > I don't see what you are saying. Suddenly guest visible > > changes within a machine type are ok? > > > > So we have a bug, need to fix it, preferably before piling up > > more features. The best way imho is for 2.4 to avoid > > this device unless requested explicitly. > > > > My take on this is that Michael would like me to have a vmport_rpc=on > option, just like vmport=on (which already exists). With a default of off. > > I have no problem adding it. > > -Don Slutz I'd prefer -device instead. This way we don't need to deal with it in PC code at all. -- MST