From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55762) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fT8pu-0000ks-Vh for qemu-devel@nongnu.org; Wed, 13 Jun 2018 12:41:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fT8pt-0001gl-VW for qemu-devel@nongnu.org; Wed, 13 Jun 2018 12:41:31 -0400 References: <20180613154711.12977-1-dplotnikov@virtuozzo.com> <20180613154711.12977-3-dplotnikov@virtuozzo.com> From: Max Reitz Message-ID: Date: Wed, 13 Jun 2018 18:41:14 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="BWjScocJUrinYWwnUaanFiVJyo2Oe3UTF" Subject: Re: [Qemu-devel] [PATCH v0 2/2] qmp: add block-set-copy-on-read command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , Denis Plotnikov , qemu-block@nongnu.org Cc: armbru@redhat.com, kwolf@redhat.com, famz@redhat.com, stefanha@redhat.com, jcody@redhat.com, qemu-devel@nongnu.org, den@virtuozzo.com, rkagan@virtuozzo.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --BWjScocJUrinYWwnUaanFiVJyo2Oe3UTF From: Max Reitz To: Eric Blake , Denis Plotnikov , qemu-block@nongnu.org Cc: armbru@redhat.com, kwolf@redhat.com, famz@redhat.com, stefanha@redhat.com, jcody@redhat.com, qemu-devel@nongnu.org, den@virtuozzo.com, rkagan@virtuozzo.com Message-ID: Subject: Re: [PATCH v0 2/2] qmp: add block-set-copy-on-read command References: <20180613154711.12977-1-dplotnikov@virtuozzo.com> <20180613154711.12977-3-dplotnikov@virtuozzo.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2018-06-13 18:02, Eric Blake wrote: > On 06/13/2018 10:47 AM, Denis Plotnikov wrote: >> The command enables/disables copy-on-read mode for VM's disk while >> VM is running. >> >> This is needed when using external disk readers to shape access patter= n >> to the disk backend. >> >> Signed-off-by: Denis Plotnikov >> --- >=20 > Deferring thoughts on the actual design for later; But why? ;-) This patch would definitely be superseded by a block reconfiguration command (i.e. presumably one that makes reopen accessible over QMP). With such a command, you could insert or remove a copy-on-read filter node at any point in time. Since we definitely want block graph configuration, I don't think we want to add special commands now. Max --BWjScocJUrinYWwnUaanFiVJyo2Oe3UTF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAlshSSoACgkQ9AfbAGHV z0CdGQgAlBWT/FqR7Vn3VUb9zJ75MP/KX2+lL5pYDnrJSX+JJcDa4+0vl4/Gcs7Y X5Jk6iWG9MeoMhP8ZUbpBCKjlJEuJGcL+KoXZWzEUeIskGXHvSWtYu4ghTa3iKqq lTGqQuPAwrNM38Cv10UNal6Ym6edOwOllPwvm3Rg+YsZH+BoMUNJuGc6QoBMc1GM PaVcl3Or2HV/+q0ALEDT25iCtw0sX7854Xuu1ZDM75MxjC+91LUdUeIkXtnzsjzk 4cY+arLJDFikuXAL1hPQfNMmx+BFrfXLVXZ/OopBvqVw/CvPMNvEanrch31vSQjI lF8pDIBgVehwO6L7tNE/c8XkpCzJjg== =OyPU -----END PGP SIGNATURE----- --BWjScocJUrinYWwnUaanFiVJyo2Oe3UTF--