From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38416) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VXvAP-0004Pi-UH for qemu-devel@nongnu.org; Sun, 20 Oct 2013 11:43:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VXvAJ-0003Vy-QW for qemu-devel@nongnu.org; Sun, 20 Oct 2013 11:43:45 -0400 Received: from ssl.dlhnet.de ([91.198.192.8]:40520 helo=ssl.dlh.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VXvAJ-0003VD-LD for qemu-devel@nongnu.org; Sun, 20 Oct 2013 11:43:39 -0400 From: Peter Lieven Date: Sun, 20 Oct 2013 17:42:58 +0200 Message-Id: <1382283791-11181-5-git-send-email-pl@kamp.de> In-Reply-To: <1382283791-11181-1-git-send-email-pl@kamp.de> References: <1382283791-11181-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCHv5 04/17] block: add logical block provisioning info to BlockDriverInfo List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Stefan Hajnoczi , Peter Lieven , ronniesahlberg@gmail.com, pbonzini@redhat.com Signed-off-by: Peter Lieven --- include/block/block.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index 1f30a56..5fbab01 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 { -- 1.7.9.5