From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49619) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VZFe5-0005LC-9B for qemu-devel@nongnu.org; Thu, 24 Oct 2013 03:47:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VZFdy-0004JY-Gr for qemu-devel@nongnu.org; Thu, 24 Oct 2013 03:47:53 -0400 Received: from mx.ipv6.kamp.de ([2a02:248:0:51::16]:36998 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VZFdy-0004J5-5r for qemu-devel@nongnu.org; Thu, 24 Oct 2013 03:47:46 -0400 From: Peter Lieven Date: Thu, 24 Oct 2013 09:46:38 +0200 Message-Id: <1382600811-20043-5-git-send-email-pl@kamp.de> In-Reply-To: <1382600811-20043-1-git-send-email-pl@kamp.de> References: <1382600811-20043-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCHv6 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: kwolf@redhat.com, stefanha@redhat.com, Peter Lieven , ronniesahlberg@gmail.com, pbonzini@redhat.com Reviewed-by: Eric Blake 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..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 { -- 1.7.9.5