From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43947) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zyw28-00015Z-Tu for qemu-devel@nongnu.org; Wed, 18 Nov 2015 01:15:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zyw25-0001qo-HZ for qemu-devel@nongnu.org; Wed, 18 Nov 2015 01:15:56 -0500 Received: from relay.parallels.com ([195.214.232.42]:42049) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zyw25-0001qe-9Y for qemu-devel@nongnu.org; Wed, 18 Nov 2015 01:15:53 -0500 Message-ID: <564C1787.8040500@virtuozzo.com> Date: Wed, 18 Nov 2015 09:15:35 +0300 From: Vladimir Sementsov-Ogievskiy MIME-Version: 1.0 References: <1447674737-32430-1-git-send-email-den@openvz.org> <564B4DB4.1070005@redhat.com> In-Reply-To: <564B4DB4.1070005@redhat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/1] parallels: add format spec List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , "Denis V. Lunev" Cc: John Snow , qemu-devel@nongnu.org, Stefan Hajnoczi On 17.11.2015 18:54, Eric Blake wrote: > On 11/16/2015 04:52 AM, Denis V. Lunev wrote: >> From: Vladimir Sementsov-Ogievskiy >> >> This specifies Parallels image format as implemented in Parallels Cloud >> Server 6.10 > Are we the canonical location of the specification? If not, do we risk > getting out of sync with the canonical Parallels Cloud Server > documentation, in which case, wouldn't it be better to point to a URL of > the externally-maintained spec rather than duplicating it here? > >> +++ b/docs/specs/parallels.txt >> @@ -0,0 +1,218 @@ >> += Parallels Expandable Image File Format = >> + > Is this document okay under the default GPLv2+ license, or does it need > to explicitly call out a different license? > > >> +== Header == >> + >> +The header is placed at the start of an image and contains the following >> +fields: >> + >> + char magic[16] >> + Must contain "WithoutFreeSpace" or "WithouFreSpacExt". >> + >> + uint32 version >> + Must be 2. >> + > You may want to compare to the qcow2 spec, which also lists expected > byte offsets for each field (rather than having to count how many > earlier fields of which widths were specified). I've compared qed spec with qcow2 spec and like the first one. What the need of specifying each offset? Creating a c-structure is simpler when you see types. and than offsetof and sizeof may be used if needed. Nobody will #define numeric offsets I think. -- Best regards, Vladimir * now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.