From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:55643) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ghIxM-0005pi-Ew for qemu-devel@nongnu.org; Wed, 09 Jan 2019 13:52:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ghIxL-0000GG-HV for qemu-devel@nongnu.org; Wed, 09 Jan 2019 13:52:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60711) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ghIxL-0000Ff-9a for qemu-devel@nongnu.org; Wed, 09 Jan 2019 13:51:59 -0500 Date: Wed, 9 Jan 2019 19:51:54 +0100 From: Kevin Wolf Message-ID: <20190109185154.GL4867@localhost.localdomain> References: <20180906111107.30684-1-danielhb413@gmail.com> <47023eb5-41f1-1b60-1094-d607999e93b6@redhat.com> <200ecea3-1ef4-3ecf-6b37-f6e45fef3849@redhat.com> <20190109172023.GK4867@localhost.localdomain> <40ef0a8d-3a25-4cc3-95f8-82bc4513776c@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tmoQ0UElFV5VgXgH" Content-Disposition: inline In-Reply-To: <40ef0a8d-3a25-4cc3-95f8-82bc4513776c@redhat.com> Subject: Re: [Qemu-devel] [PATCH v2 0/3] HMP/snapshot changes - do not use ID anymore List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Max Reitz , armbru@redhat.com, Daniel Henrique Barboza , qemu-devel@nongnu.org, muriloo@linux.ibm.com, dgilbert@redhat.com --tmoQ0UElFV5VgXgH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Am 09.01.2019 um 18:55 hat Eric Blake geschrieben: > On 1/9/19 11:38 AM, Max Reitz wrote: >=20 > >>>>> I do think it affects users of HMP, because right now you can delete > >>>>> snapshots with their ID, and after this series you cannot. > >>>> >=20 > >> This. Is. HMP. > >> > >> Not a stable ABI, no deprecation period of two releases. > >=20 > > Well, if you want to do it. > >=20 > > This may be HMP, but this is also the only interface to savevm, so it's > > not like users have a choice to use a more stable interface. I know > > that was a conscious decision, more or less, but I don't see why we need > > to be so nasty when the hardest thing about doing a nice deprecation > > would be to remember to make it an error in half a year. >=20 > Indeed, and libvirt IS using 'savevm' via HMP via QMP's > human-monitor-command, since there is no QMP counterpart for internal > snapshot. Even though lately we consistently tell people that internal > snapshots are underdeveloped and you should use external snapshots, it > does not get away from the fact that libvirt has been using 'savevm' to > drive internal snapshots for years now, and that we MUST consider > back-compat and/or add an introspectible QMP interface before making > changes that would break libvirt. Okay, so what does libvirt do when you request a snapshot with a numerical name? Without having looked at the code, the best case I would expect that it forbids them, and more realistically I suspect that we may actually fix a bug for libvirt by changing the semantics. Or does libvirt really use snapshot IDs rather than names? Kevin --tmoQ0UElFV5VgXgH Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBAgAGBQJcNkLKAAoJEH8JsnLIjy/W+v8P/3gS8w/e672hhGUHUuTqE7sF ll3ngwiOls5CGyXdyQiqALLL9VehUaI55bn7h4J/xgpaTb7TXJhBD6I3QZGkTvuy EGp7vAFVQVaOa1kXAO+9+x7m2BpveGWJrwH9RdItq3cKXjou4Wbh5ZXKRiDQQqFu 5PvWfvfgA9EPxSJd75KZRBfMHwK/sKqTisAsMjXkjCdWmA84fzn+BxBLiX+J2sQE 5bLlauetQNPgnfM8xAneifPL1YUMn0nKz02M+7/4U4fAQTNrzIpBfCIkaLVaoZNC xa1yUh/geVqiQ4f+dZuugWiXwR9IKoyDxeKmVZcCU4b7jTon1N1xh5jZtOsCEsFd 3k8tIJgHKUldmEqaerpYHBIRy57vJf5qufa+R+RcJZkNtwf2hdxTrTBhl1lkeRDQ FaxZppFLZDomp993dPND+GZxI75y/qfjboizJ5lC+9VAstzZ/S+ldpnMHC2BnqqX 4op6ZfGU7XgkH28Epr+4fEfm4tB6zfITDp7wndjLecNF4ExsBsCm5d8zIm/5o9zE SU4GH7aAFWVPn2G+U0HAvxcQX+hRSrVu6zFa3mE5Fxgbpei1eudcvTJaljJcG8Yb 4WLmoaAEV0Sbn95RzGy972UJWYfSd/F1S2vwhPEv8Lh/Jx7K/eP++JuT9PYxMKYT T/lhGChIEgDfUmkZLaIE =pQx7 -----END PGP SIGNATURE----- --tmoQ0UElFV5VgXgH--