From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:42425) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUfNG-0002rU-J2 for qemu-devel@nongnu.org; Tue, 23 Apr 2013 11:43:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UUfNB-00015w-Gr for qemu-devel@nongnu.org; Tue, 23 Apr 2013 11:43:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54617) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUfNB-00015q-8c for qemu-devel@nongnu.org; Tue, 23 Apr 2013 11:43:13 -0400 Message-ID: <5176A98F.9050809@redhat.com> Date: Tue, 23 Apr 2013 09:32:31 -0600 From: Eric Blake MIME-Version: 1.0 References: <1366365123-5412-1-git-send-email-akong@redhat.com> <51716101.8090705@redhat.com> <20130422114841.GA4053@t430s.nay.redhat.com> <517527FC.2090808@redhat.com> <51755075.1000008@redhat.com> <20130423092040.7179f3ce@redhat.com> In-Reply-To: <20130423092040.7179f3ce@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="----enig2MAPFBLVDTBWVTMHWLTIE" Subject: Re: [Qemu-devel] [PATCH] monitor: introduce query-config-schema List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: aliguori@us.ibm.com, mdroth@linux.vnet.ibm.com, qemu-devel@nongnu.org, jyang@redhat.com, Paolo Bonzini , Amos Kong This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2MAPFBLVDTBWVTMHWLTIE Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 04/23/2013 07:20 AM, Luiz Capitulino wrote: > On Mon, 22 Apr 2013 09:00:05 -0600 > Eric Blake wrote: >=20 >> At any rate, we really DO want introspection, and having it in 1.5 is = a >> worthwhile goal. Even if the introspection turns up empty on legacy >> options, having it for the sake of new options is worth the effort. >=20 > Agreed. But as you said in another email, we need a JSON representation= > for this command. Dumping all options as strings is just like using -he= lp. >=20 > Something else that has occurred to me is that, do we want this to be > a QMP command or do we want this to be a command-line option? If we do = this > as a QMP command then libvirt would have to actually start QEMU just to= > query supported options. A command-line option might (or might not) be useful to humans, but a QMP command is what libvirt wants. Libvirt already starts a QMP session for lots of other queries (not the least of which is the 'query-commands' query which would let us know whether to even expect the new QMP command for command-line introspection to work). Adding one more QMP query to the mix called by libvirt is easy (no additional processes, and the response already goes through the JSON parser that handles all QMP responses); adding a new command line option is more expensive (we would have to start qemu once to use the command line option, then again for the QMP queries; also, it's more coding effort to wire up libvirt to pass the stdout from the command line call into the JSON parser that was normally expecting data from a Unix socket). >=20 > Another interesting point is about full schema introspection. This patc= h > only supports command-line options. It would be desirable to be able to= > introspect all QAPI types and QMP commands, although I'm aware that thi= s > might be a lot of work to do for 1.5. Based on the call today, getting introspection for command line additions in time for 1.5, and saving full QMP introspection until 1.6, would be reasonable; libvirt's immediate goal is to determine when it is safe to use new command line options while doing its one-shot QMP probing of a qemu binary. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org ------enig2MAPFBLVDTBWVTMHWLTIE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJRdqmPAAoJEKeha0olJ0NqIuAH/1vG/F4rsxukEY/6zp9th99s /d226PMfQyqX5duEnGZvj+STdwCAMEx3VQQhK8zEJkinmeWhlhg4h4yRkwXegloy zUuJssIGmWfzXHyYc0cQL9XTCY+VYRSBfrfIirl3L/ZpjdM2UmdOKqix1S0yWWIF L4atJi8Ft44dr+CBL91rLQPTlMalbauO/PO9lUWD7EZJXiTg3FdSNqFOZaTOXznr 9GrJxfyr8mMgGMGT9qGMTKes1wEjaFwTmDDlCLCRKVPDOXDOsz5KRMzhhb+sLjuS NqEVwZ4g36z7jybEejgTIn81FW/jm1QcC2ibI1H3e7zlq0fQT4CCo6BeBLMRUfk= =zSUC -----END PGP SIGNATURE----- ------enig2MAPFBLVDTBWVTMHWLTIE--