From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53731) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmRD3-0003ZR-QR for qemu-devel@nongnu.org; Fri, 29 Nov 2013 11:46:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VmRCx-0002mZ-U8 for qemu-devel@nongnu.org; Fri, 29 Nov 2013 11:46:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:63864) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmRCx-0002mN-M7 for qemu-devel@nongnu.org; Fri, 29 Nov 2013 11:46:23 -0500 From: Kevin Wolf Date: Fri, 29 Nov 2013 17:45:19 +0100 Message-Id: <1385743555-27888-5-git-send-email-kwolf@redhat.com> In-Reply-To: <1385743555-27888-1-git-send-email-kwolf@redhat.com> References: <1385743555-27888-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 04/41] block: add logical block provisioning info to BlockDriverInfo List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Peter Lieven Reviewed-by: Eric Blake Signed-off-by: Peter Lieven Signed-off-by: Stefan Hajnoczi --- include/block/block.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index 1f30a56..9c76967 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -18,6 +18,22 @@ typedef struct BlockDriverInfo { /* offset at which the VM state can be saved (0 if not possible) */ int64_t vm_state_offset; bool is_dirty; + /* + * True if unallocated blocks read back as zeroes. This is equivalent + * to the the LBPRZ flag in the SCSI logical block provisioning page. + */ + bool unallocated_blocks_are_zero; + /* + * True if the driver can optimize writing zeroes by unmapping + * sectors. This is equivalent to the BLKDISCARDZEROES ioctl in Linux + * with the difference that in qemu a discard is allowed to silently + * fail. Therefore we have to use bdrv_write_zeroes with the + * BDRV_REQ_MAY_UNMAP flag for an optimized zero write with unmapping. + * After this call the driver has to guarantee that the contents read + * back as zero. It is additionally required that the block device is + * opened with BDRV_O_UNMAP flag for this to work. + */ + bool can_write_zeroes_with_unmap; } BlockDriverInfo; typedef struct BlockFragInfo { -- 1.8.1.4