From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43726) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwrOB-0004ra-At for qemu-devel@nongnu.org; Fri, 05 Dec 2014 06:49:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XwrO5-0002pR-5i for qemu-devel@nongnu.org; Fri, 05 Dec 2014 06:49:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55474) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwrO4-0002pK-UL for qemu-devel@nongnu.org; Fri, 05 Dec 2014 06:49:29 -0500 Date: Fri, 5 Dec 2014 12:49:22 +0100 From: Kevin Wolf Message-ID: <20141205114922.GC6040@noname.str.redhat.com> References: <1417775209-11812-1-git-send-email-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1417775209-11812-1-git-send-email-kwolf@redhat.com> Subject: Re: [Qemu-devel] [PATCH] vhdx: Return true for bdrv_has_zero_init List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: amulya.lokesha@emc.com, jcody@redhat.com, stefanha@redhat.com, mreitz@redhat.com Am 05.12.2014 um 11:26 hat Kevin Wolf geschrieben: > Like for most other image formats, vhdx images read as all zero in qemu > after their creation (we're taking advantage from the fact that qemu has > just created the image, because PAYLOAD_BLOCK_NOT_PRESENT actually means > undefined rather than zeroed according to the spec). > > This fixes that 'qemu-img convert' to vhdx fully populates the image. > > Signed-off-by: Kevin Wolf Jeff, another thing that Max found while we looked at the spec is that the 1.0 spec defines PAYLOAD_BLOCK_UNMAPPED as 3, but we define it as 5. It appears that the 0.95 spec actually had it that way. Should we handle both 3 and 5 as unmapped? Kevin