From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2DD6BC61DA4 for ; Sat, 18 Mar 2023 12:07:52 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pdVKm-0007I7-8o; Sat, 18 Mar 2023 08:06:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pdVKi-0007Hk-Sd for qemu-devel@nongnu.org; Sat, 18 Mar 2023 08:06:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pdVKh-0002g6-77 for qemu-devel@nongnu.org; Sat, 18 Mar 2023 08:06:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679141205; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JIJ9rC5OpUCmMBz9W7E5xdMT7UmL8CA5m6yZrWDo4KQ=; b=cV2r0G2xXVf0OKTG1pqJiCv/Z0sFXFQ9GKXoITiT5u3jZQwLHHJ5WyRvsDBlZghQHYSQF6 hjZ3dNUkrim44mvxD8R6CmSwrjHIfptllEIe4m12RPKiDIns7MC12LABzkJORYlJSSl+rf MIwUn2NXKBLIXRv8AOgAt7S3cuakkdg= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-646-q9VIdHQqNkKb4EBERp-kpg-1; Sat, 18 Mar 2023 08:06:43 -0400 X-MC-Unique: q9VIdHQqNkKb4EBERp-kpg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4B78A1C05141; Sat, 18 Mar 2023 12:06:43 +0000 (UTC) Received: from redhat.com (unknown [10.2.16.99]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 20ED81121315; Sat, 18 Mar 2023 12:06:42 +0000 (UTC) Date: Sat, 18 Mar 2023 07:06:40 -0500 From: Eric Blake To: Hanna Czenczek Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Vladimir Sementsov-Ogievskiy , Kevin Wolf , Stefan Hajnoczi , Fam Zheng Subject: Re: [PATCH 1/4] util/iov: Make qiov_slice() public Message-ID: <20230318120640.ewhjipdc57cm5z3k@redhat.com> References: <20230317175019.10857-1-hreitz@redhat.com> <20230317175019.10857-2-hreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230317175019.10857-2-hreitz@redhat.com> User-Agent: NeoMutt/20220429 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Mar 17, 2023 at 06:50:16PM +0100, Hanna Czenczek wrote: > We want to inline qemu_iovec_init_extended() in block/io.c for padding > requests, and having access to qiov_slice() is useful for this. > > (We will need to count the number of I/O vector elements of a slice > there, and then later process this slice. Without qiov_slice(), we > would need to call qemu_iovec_subvec_niov(), and all further > IOV-processing functions may need to skip prefixing elements to > accomodate for a qiov_offset. Because qemu_iovec_subvec_niov() > internally calls qiov_slice(), we can just have the block/io.c code call > qiov_slice() itself, thus get the number of elements, and also create an > iovec array with the superfluous prefixing elements stripped, so the > following processing functions no longer need to skip them.) Might be worth mentioning in the commit message that you also renamed it to qemu_iovec_slice() as part of exporting. > > Signed-off-by: Hanna Czenczek > --- > include/qemu/iov.h | 3 +++ > util/iov.c | 14 +++++++------- > 2 files changed, 10 insertions(+), 7 deletions(-) Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org