From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36239) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z35EY-00058z-2C for qemu-devel@nongnu.org; Thu, 11 Jun 2015 12:21:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z35ET-0006kj-I3 for qemu-devel@nongnu.org; Thu, 11 Jun 2015 12:21:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55607) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z35ET-0006kH-B1 for qemu-devel@nongnu.org; Thu, 11 Jun 2015 12:21:33 -0400 Message-ID: <5579B58B.6020408@redhat.com> Date: Thu, 11 Jun 2015 12:21:31 -0400 From: John Snow MIME-Version: 1.0 References: <1433776886-27239-1-git-send-email-vsementsov@virtuozzo.com> <1433776886-27239-2-git-send-email-vsementsov@virtuozzo.com> <20150609170325.GI3181@stefanha-thinkpad.redhat.com> <5577F312.9040502@virtuozzo.com> <20150610132420.GD2430@stefanha-thinkpad.home> <557960AC.4080607@virtuozzo.com> <20150611130309.GD9425@stefanha-thinkpad.redhat.com> In-Reply-To: <20150611130309.GD9425@stefanha-thinkpad.redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/8] spec: add qcow2-dirty-bitmaps specification List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi , Vladimir Sementsov-Ogievskiy Cc: kwolf@redhat.com, qemu-devel@nongnu.org, Vladimir Sementsov-Ogievskiy , Stefan Hajnoczi , den@openvz.org, pbonzini@redhat.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 06/11/2015 09:03 AM, Stefan Hajnoczi wrote: > On Thu, Jun 11, 2015 at 01:19:24PM +0300, Vladimir > Sementsov-Ogievskiy wrote: >> On 10.06.2015 16:24, Stefan Hajnoczi wrote: >>> On Wed, Jun 10, 2015 at 11:19:30AM +0300, Vladimir >>> Sementsov-Ogievskiy wrote: >>>> On 09.06.2015 20:03, Stefan Hajnoczi wrote: >>>>> On Mon, Jun 08, 2015 at 06:21:19PM +0300, Vladimir >>>>> Sementsov-Ogievskiy wrote: >>>>>> @@ -166,6 +167,19 @@ the header extension data. Each >>>>>> entry look like this: terminated if it has full length) >>>>>> +== Dirty bitmaps == + +Dirty bitmaps is an optional >>>>>> header extension. It provides a possibility of +storing >>>>>> dirty bitmaps in qcow2 image. The fields are: + + >>>>>> 0 - 3: nb_dirty_bitmaps + Number of >>>>>> dirty bitmaps contained in the image >>>>> Is there a maximum? >>>> hmm. any proposals for this? >>> 65535 seems practical. >> >> So, you suggest to reduce this field width to 2b? And additional >> 2 bytes reserved field, to achieve 8b-alignment? > > No, I would leave it 32-bit but impose a little (which can be > increased later if necessary). That's how nb_snapshots works too. > Doesn't the code already limit the number of bitmaps via +#define QCOW_MAX_DIRTY_BITMAPS 65536, from patch 2? -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJVebWLAAoJEH3vgQaq/DkOJCYP/jUSJT+jhb3+GvAtddCssyYR u1BHZacXyTsDTwX4WDZQ5eGEZJZeSwu7++w5N+m+62yDxervarfEE0G/nuGRSNWx 0zYF0RrlYZFdDqed18rgXJJjCtNo1jp67ojk+xpEBUMx9cgFa6s+BTkrY0h+4hiO V3mvU0H1+8by1Ss5lvziKCHdrksGyBIS4gw+WZNshdOc46/nBZfSlh6CWmtOO/5S XZwXLKE7QMJMzigdcLJBOlymRwnF094Myklf8fZQILgbdoHoKhEEj9gVWkSpoNk9 FkMDDS1qN5vtYy5Ehzwy9QpbsN5ZEhuHoj5N8k0vDfFHgB9KKvOChvxf2lVhgbz7 fvGpqUb4eEdTvRno9V+8KoEcs99JXLvhed8LrfcZzq05WKbLeAdXYj18QrDw8pdY Fl4kV5Ca4dpvDAcNZDlCKERv+STLh56hYXEYtjzNEXL+ryQwUyHetY/M6Qodq0j2 FtJq21aj68vEOovQQcX2QxqRxkPzDEvNPbM+phBOh2FjQkbvB6I5bs/ueloyi2q9 UtXWhR6ImUgA6LN25OIc6GS9xYJsFiQlLh1uI/bJoDEpQvVnMojAXE7SohyTya89 2+HIGJsdkbBZsc4SN1INqcsRCeN1at8KiwdIbAijrciF9WIsv0kUEvCvmA93UVYp s2Os9g5QgMXrK1icCK5J =CIuZ -----END PGP SIGNATURE-----