From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:41861) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RWYnp-000398-9o for qemu-devel@nongnu.org; Fri, 02 Dec 2011 14:29:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RWYnn-0006D7-Vh for qemu-devel@nongnu.org; Fri, 02 Dec 2011 14:29:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:1483) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RWYnn-0006CE-M6 for qemu-devel@nongnu.org; Fri, 02 Dec 2011 14:29:43 -0500 Message-ID: <4ED9271E.7020800@redhat.com> Date: Fri, 02 Dec 2011 12:29:34 -0700 From: Eric Blake MIME-Version: 1.0 References: <4ED8DF02.5060605@redhat.com> <4ED8E5A3.2080909@codemonkey.ws> <20111202150850.GJ2274323@orkuz.home> <4ED8EB8B.9090800@codemonkey.ws> In-Reply-To: <4ED8EB8B.9090800@codemonkey.ws> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enigB2CE8C7169FC84A95B9BBE47" Subject: Re: [Qemu-devel] [libvirt] libvirt doesn't work with qemu 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: libvir-list@redhat.com, Gerd Hoffmann , "qemu-devel@nongnu.org" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigB2CE8C7169FC84A95B9BBE47 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 12/02/2011 08:15 AM, Anthony Liguori wrote: >> Which of course only works with new enough QEMU that is known to >> support QMP >> (which BTW we detect by checking the version number). >=20 > Or you could just try the -qmp option and if QEMU exits, it doesn't > support it. That's going to be a lot more reliable than checking a > version number. But we already have to call 'qemu -h' for other reasons; so we might as well be efficient and learn as much as possible from that result than by calling both 'qemu -h' and 'qemu -qmp ...', in order to probe what qemu supports. Also, 'qemu -qmp' doesn't work. What's the proper syntax for invoking qemu in order to query QMP capabilities, but without also starting up a guest? At any rate, yes, we want to improve libvirt to cache qemu capabilities, to do the probing once at startup and then again any time the mtime of the qemu binary changes, rather than the current policy of doing it on every VM startup; once we cache information, making multiple probes will still be more efficient in the long ran than the current probe per guest.= --=20 Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --------------enigB2CE8C7169FC84A95B9BBE47 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBCAAGBQJO2SceAAoJEKeha0olJ0NqCUQH/RC9zYcB6aiiA/9t7H6pXwLG pR60cYSGDKIUBm3AAfBKlnMSKuymIH4wY2B5sm0UmKzNT4enFXqeTOqjPwe0z4xr 5ctC8UG25IodzWq3uNDogiLfk76/A4x+69vEs/C8fgZXFCyPqUSimPB0bU05N593 9R4C4n9HJpqJKjR50K2fxLnybuGdo6vXbflvbqp2Gs+Td3zG5T7mZpWZmZ7YPJti 1QqX6CoVp/P6Ca0QtEE8Ahdq79IuvYlhvIqQkBnCXArAdTjixVLSOWd7SkgVbpgB ngEBbT+4tlRs5ZupZa2hmN/Zh4hrjUoUZatMcY5p2kpGJyxwUMQm0hsM4jK9hcM= =JiSw -----END PGP SIGNATURE----- --------------enigB2CE8C7169FC84A95B9BBE47--