From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39604) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XW7G3-00005U-0j for qemu-devel@nongnu.org; Mon, 22 Sep 2014 13:18:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XW7Fx-0003xN-Sk for qemu-devel@nongnu.org; Mon, 22 Sep 2014 13:18:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12101) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XW7Fx-0003wX-KJ for qemu-devel@nongnu.org; Mon, 22 Sep 2014 13:18:33 -0400 Date: Mon, 22 Sep 2014 20:21:35 +0300 From: "Michael S. Tsirkin" Message-ID: <20140922172135.GC11272@redhat.com> References: <1411310339-27733-1-git-send-email-alex@alex.org.uk> <1411310339-27733-3-git-send-email-alex@alex.org.uk> <20140922113655.GI14882@redhat.com> <871tr37jsv.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871tr37jsv.fsf@blackfin.pond.sub.org> Subject: Re: [Qemu-devel] [PATCH v3 2/2] Add configure option --enable-pc-1-0-qemu-kvm List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Ryan Harper , Serge Hallyn , "quintela@redhat.com" , Libvirt , Serge Hallyn , qemu-devel@nongnu.org, Alexander Graf , Alex Bligh , Cole Robinson , Amit Shah , Bruce Rogers , Andreas =?iso-8859-1?Q?F=E4rber?= , "Serge E. Hallyn" On Mon, Sep 22, 2014 at 05:32:16PM +0200, Markus Armbruster wrote: > "Michael S. Tsirkin" writes: > > > On Sun, Sep 21, 2014 at 03:38:59PM +0100, Alex Bligh wrote: > >> Add a configure option --enable-pc-1-0-qemu-kvm and the > >> corresponding --disable-pc-1-0-qemu-kvm, defaulting > >> to disabled. > >> > >> Rename machine type pc-1.0 to pc-1.0-qemu-git. > >> > >> Make pc-1.0 machine type an alias of either pc-1.0-qemu-kvm > >> or pc-1.0-qemu-git depending on the value of the config > >> option. > >> > >> Signed-off-by: Alex Bligh > > > > I have to say, this one bothers me. > > We end up not being able to predict what does pc-1.0 > > reference. > > > > Users also don't get qemu from git so I don't see > > why does git make sense in the name? > > > > Legacy management applications invoked qemu as qemu-kvm - > > how about detecting that name and switching > > the machine types? > > Ugh! I like that even less than a configure option. configure options are tested even less than runtime ones: each distro has to pick up a set of options and all users are stuck with it. So let's assume Ubuntu sets this and something is broken. How is a Fedora user to test this? Find out configure flags that Ubuntu uses and rebuild from source? It's hard to get people to triage bugs as it is. That's why changing behaviour in subtle ways depending on configure options is a very bad idea. So a flag might be better, but if we want to be compatible with qemu-kvm, poking at argv[0] still better than configure. > > It might make sense to also set -enable-kvm and > > change default CPU to kvm64 in this case. > > Yup.