From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39044) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxt4e-0006yM-LR for qemu-devel@nongnu.org; Tue, 11 Apr 2017 06:31:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxt4d-00049d-PY for qemu-devel@nongnu.org; Tue, 11 Apr 2017 06:31:00 -0400 Date: Tue, 11 Apr 2017 12:30:49 +0200 From: Kashyap Chamarthy Message-ID: <20170411103049.dqjkpgjszaqb5xn3@eukaryote> References: <20170324123458.yk3rj3g47e5xr33i@eukaryote> <0e1c78f3-1b82-58e4-035e-944484e66f29@redhat.com> <20170404132815.aactqo2o5izpzclf@eukaryote> <8420253d-261f-f040-6815-c949b8a2cce2@redhat.com> <877f2rcmbf.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877f2rcmbf.fsf@dusky.pond.sub.org> Subject: Re: [Qemu-devel] [Qemu-block] Making QMP 'block-job-cancel' transactionable List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Eric Blake , John Snow , qemu-devel@nongnu.org, qemu-block@nongnu.org On Tue, Apr 11, 2017 at 11:42:28AM +0200, Markus Armbruster wrote: > Eric Blake writes: > > > On 04/04/2017 08:28 AM, Kashyap Chamarthy wrote: > > > >>> Minor or not, it is a useful viewpoint. Either way, as long as the new > >>> way of getting a transactional non-pivot successful completion is > >>> something that libvirt can learn via introspection, > >> > >> Can you elaborate a little more on the above, for my own edification -- > >> how might it be possible for "libvirt can learn via introspection"? Is > >> it via some method using the QMP 'query-commands' / > >> 'query-command-line-options'? > > > > Those, and query-qmp-schema. > > Avoid query-command-line-options if you can. If you can't, know its > limitations and quirks. Thanks; I actually meant to mention 'query-qmp-schema' (thanks to Eric for correcting). And I didn't fortet your reminder of the incompleteness / limitations of 'query-command-line-options' from your KVMForum 2015 presentation :-) > > > If the change includes the addition of > > something new in the .json files describing QMP, then query-qmp-schema > > will let libvirt probe whether the version of qemu it it talking to has > > that new field or not (presumably, in this case it would be a new > > optional bool member to select the mode when creating a job, as well as > > a new command visible through query-commands to change the mode of a > > running job). -- /kashyap