From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51827) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ddaFW-0003tl-Oo for qemu-devel@nongnu.org; Fri, 04 Aug 2017 06:55:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ddaES-0006R0-Hy for qemu-devel@nongnu.org; Fri, 04 Aug 2017 06:54:34 -0400 From: "Daniel P. Berrange" Date: Fri, 4 Aug 2017 11:50:59 +0100 Message-Id: <20170804105059.11941-1-berrange@redhat.com> Subject: [Qemu-devel] [PATCH] block: document semanatics of bdrv_co_preadv|pwritev List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Stefan Hajnoczi , Fam Zheng , Kevin Wolf , Max Reitz , "Daniel P. Berrange" Signed-off-by: Daniel P. Berrange --- include/block/block_int.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/include/block/block_int.h b/include/block/block_int.h index d4f4ea7584..deb81a58bd 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -147,12 +147,41 @@ struct BlockDriver { int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); + + /** + * @offset: position in bytes to read at + * @bytes: number of bytes to read + * @qiov: the buffers to fill with read data + * + * @offset and @bytes will be a multiple of 'request_alignment', + * but the length of individual @qiov elements does not have to + * be a multiple. + * + * @bytes may be less than the total sizeof @iov, and will be + * no larger than 'max_transfer'. + * + * The buffer in @qiov may point directly to guest memory. + */ int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); int coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags); + /** + * @offset: position in bytes to write at + * @bytes: number of bytes to write + * @qiov: the buffers containing data to write + * + * @offset and @bytes will be a multiple of 'request_alignment', + * but the length of individual @qiov elements does not have to + * be a multiple. + * + * @bytes may be less than the total sizeof @iov, and will be + * no larger than 'max_transfer'. + * + * The buffer in @qiov may point directly to guest memory. + */ int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); -- 2.13.3