From patchwork Fri Aug 4 10:50:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 9881411 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0461D603F4 for ; Fri, 4 Aug 2017 14:45:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E8FBA28455 for ; Fri, 4 Aug 2017 14:45:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DDB4B2884B; Fri, 4 Aug 2017 14:45:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8EBED28455 for ; Fri, 4 Aug 2017 14:45:31 +0000 (UTC) Received: from localhost ([::1]:35878 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dddr0-0003IF-IO for patchwork-qemu-devel@patchwork.kernel.org; Fri, 04 Aug 2017 10:45:30 -0400 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 Received: from mx1.redhat.com ([209.132.183.28]:57280) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ddaCE-0003XY-D0; Fri, 04 Aug 2017 06:51:10 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 17DBB15557; Fri, 4 Aug 2017 10:51:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 17DBB15557 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=berrange@redhat.com Received: from t460.redhat.com (ovpn-117-145.ams2.redhat.com [10.36.117.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6DEE489A85; Fri, 4 Aug 2017 10:51:03 +0000 (UTC) From: "Daniel P. Berrange" To: qemu-devel@nongnu.org Date: Fri, 4 Aug 2017 11:50:59 +0100 Message-Id: <20170804105059.11941-1-berrange@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 04 Aug 2017 10:51:09 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] block: document semanatics of bdrv_co_preadv|pwritev X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-block@nongnu.org, Max Reitz , Stefan Hajnoczi , Fam Zheng Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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);