From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LNZJ9-0008Av-T0 for qemu-devel@nongnu.org; Thu, 15 Jan 2009 15:59:19 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LNZJ8-0008AL-FH for qemu-devel@nongnu.org; Thu, 15 Jan 2009 15:59:19 -0500 Received: from [199.232.76.173] (port=39004 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LNZJ7-0008A5-T1 for qemu-devel@nongnu.org; Thu, 15 Jan 2009 15:59:18 -0500 Received: from mx1.redhat.com ([66.187.233.31]:60245) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LNZJ7-0003Kh-Cj for qemu-devel@nongnu.org; Thu, 15 Jan 2009 15:59:17 -0500 Date: Thu, 15 Jan 2009 20:58:42 +0000 From: "Daniel P. Berrange" Subject: Re: [Qemu-devel] Re: Machine-readable or parseable qemu output Message-ID: <20090115205842.GJ23380@redhat.com> References: <20090114111005.GB31839@amit-x200.pnq.redhat.com> <20090114112317.GD24995@redhat.com> <496F9C19.8020502@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <496F9C19.8020502@codemonkey.ws> Reply-To: "Daniel P. Berrange" , qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: chrisw@redhat.com, dlaor@redhat.com, rjones@redhat.com, qemu-devel@nongnu.org, avi@redhat.com, Amit Shah On Thu, Jan 15, 2009 at 02:27:05PM -0600, Anthony Liguori wrote: > Daniel P. Berrange wrote: > >On Wed, Jan 14, 2009 at 04:40:05PM +0530, Amit Shah wrote: > > > >>Hello, > >> > >>Continuing from the thread at [1], building on Daniel's suggestions, I > >>have jot down a few points as to how a libqemumonitor API could be > >>developed. > >> > >>To recap, there has to be an interface to the qemu monitor in > >>a way that wouldn't break even if the monitor output changes. This API > >>will remain the same, so that consumers (libvirt, etc) can safely > >>integrate with the monitor. > >> > >>Please see Dan's email at [1] to get the background details. > >> > >>[1] http://www.mail-archive.com/qemu-devel@nongnu.org/msg14615.html > >> > >>Here are some initial thoughts. Comments? > >> > > > >I'd like to add one more requirement > > > > - Works with existing QEMU monitor for releases >= 0.8.0 > > > > I think this is a bad requirement. > > >This is because libvirt currently supports all QEMU >= 0.8.0, > > libvirt has no bearing on upstream QEMU support :-) > > > so if > >we're to be able to make use of this library we can't restrict it > >to just new releases. > > But you can conditionally use the new library instead of your custom > parsing code for newer QEMU versions. That is true, but if there are a number of apps around which want to support multiple versions of QEMU, it is beneficial to centralize this conditional logic in libqemumonitor.so instead, of making each app implement the compat logic for the existing monitor format. I'm not against adding a new machine friendly monitor format, I'd just prefer it if one library API could provide impl for both old and new format, obviously preferring to use the new format where available. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|