From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34076) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQZzA-0003HT-Ri for qemu-devel@nongnu.org; Wed, 06 Jun 2018 11:04:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQZzA-0002JN-25 for qemu-devel@nongnu.org; Wed, 06 Jun 2018 11:04:28 -0400 References: <20180528212054.GH2209@redhat.com> <20180528212510.GC4660@redhat.com> <20180529064415.GA4756@localhost.localdomain> <2b3eef00-f326-c1e6-0e4b-b7602646eec4@redhat.com> <20180606123237.2235ae4a@kitsune.suse.cz> <20180606131929.44d0fd6b@kitsune.suse.cz> <93233bff-604b-c891-90ce-64fe1eaaaab5@redhat.com> <20180606113720.GA2661@work-vm> <2c833e2c-f0bb-ea98-a703-54fb9447bd2f@redhat.com> <20180606174412-mutt-send-email-mst@kernel.org> From: Max Reitz Message-ID: <4d65e825-5018-a29e-e883-1370ca5461b3@redhat.com> Date: Wed, 6 Jun 2018 17:04:17 +0200 MIME-Version: 1.0 In-Reply-To: <20180606174412-mutt-send-email-mst@kernel.org> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="qQHWWHeZiy0gRtMiFVIvz7N4vYTOfOEmu" Subject: Re: [Qemu-devel] storing machine data in qcow images? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: "Dr. David Alan Gilbert" , =?UTF-8?Q?Michal_Such=c3=a1nek?= , Kevin Wolf , ehabkost@redhat.com, qemu-block@nongnu.org, "Richard W.M. Jones" , qemu-devel@nongnu.org, stefanha@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --qQHWWHeZiy0gRtMiFVIvz7N4vYTOfOEmu From: Max Reitz To: "Michael S. Tsirkin" Cc: "Dr. David Alan Gilbert" , =?UTF-8?Q?Michal_Such=c3=a1nek?= , Kevin Wolf , ehabkost@redhat.com, qemu-block@nongnu.org, "Richard W.M. Jones" , qemu-devel@nongnu.org, stefanha@redhat.com Message-ID: <4d65e825-5018-a29e-e883-1370ca5461b3@redhat.com> Subject: Re: [Qemu-devel] storing machine data in qcow images? References: <20180528212054.GH2209@redhat.com> <20180528212510.GC4660@redhat.com> <20180529064415.GA4756@localhost.localdomain> <2b3eef00-f326-c1e6-0e4b-b7602646eec4@redhat.com> <20180606123237.2235ae4a@kitsune.suse.cz> <20180606131929.44d0fd6b@kitsune.suse.cz> <93233bff-604b-c891-90ce-64fe1eaaaab5@redhat.com> <20180606113720.GA2661@work-vm> <2c833e2c-f0bb-ea98-a703-54fb9447bd2f@redhat.com> <20180606174412-mutt-send-email-mst@kernel.org> In-Reply-To: <20180606174412-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2018-06-06 16:46, Michael S. Tsirkin wrote: > On Wed, Jun 06, 2018 at 01:44:02PM +0200, Max Reitz wrote: >> Because it's a hack, right. Storing binary data in a qcow2 file, >> completely ignoring it in qemu (and being completely unusable to any >> potential other users of the qcow2 format[1]) and only interpreting it= >> somewhere up the stack is a hack. >=20 > It's just a first step and it ensures compatibility with old QEMU > versions. But down the road I think we will start warning > user if the machine type does not match, and possibly even > get the type from there if user didn't supply it. If it's a first step we should have an idea on what the following steps should be. I don't want people to convince me that adding a blob to qcow2 is a good idea because "we are only going to store two or three values!" and then that blob grows out of control because "well, now we have it anyway". Max --qQHWWHeZiy0gRtMiFVIvz7N4vYTOfOEmu Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAlsX9/EACgkQ9AfbAGHV z0AVHAf/d+adyo92rmY74lrrkcYaDWI48ScT4xyDTlS0KGONrY2cJBwEDS80zqKj KglMffzdbrvzAtgElnnZK8+5khAp1oEn4UU3HLPsjKfpUjAEXI67ndRw2zDoqZ+1 4VtFCyEgMGXp6B3u2F98ucL7FgzAPVRbx0grgy/vru18QUsocjtbglNfPXn4/6e0 Orh3C+8bTuc6V/WrmRUi3VLbfqI3tu3f+ZhHlriAfVokl7xZms7+/afiHTc3cbpC j8oyMgYXKNqe+uqnm+cZK00mIs6wtQL5kEa+/x0S9OEstwV6dQ2ji7gxnDZI4fAC j9l95FAPy3wirKadmanuX4Exj26F8A== =iMEx -----END PGP SIGNATURE----- --qQHWWHeZiy0gRtMiFVIvz7N4vYTOfOEmu--