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 CFD7BC19F2A for ; Thu, 11 Aug 2022 19:11:49 +0000 (UTC) Received: from localhost ([::1]:42104 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oMDau-0005UD-Vd for qemu-devel@archiver.kernel.org; Thu, 11 Aug 2022 15:11:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34752) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oMDZF-0003Oj-U7 for qemu-devel@nongnu.org; Thu, 11 Aug 2022 15:10:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42872) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oMDZD-0001Aw-UX for qemu-devel@nongnu.org; Thu, 11 Aug 2022 15:10:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660245003; 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=rDfv+8GgVRJAU021J5fi2MP03MTmpRcw+d8Q3GXn2m4=; b=WgNyzfwNQ4zBjvQZErw7Ecwk51ZBKyym1fGIXaBM/RKF1WAB+0exSqjV2M4W0tdZnYLbqS Yo9F8DCww1nKOsO6xo6an0ldSo1Rzj1z4BJ5jsBu5ULYzAweEBK8/nXRbmDkwceUBR4L7s iJdRj/LOj5dOwtQ7rPyeDMuXlzrMZ3E= 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-62-Rv5FofBVPn6xm7VxMlK0kg-1; Thu, 11 Aug 2022 15:09:59 -0400 X-MC-Unique: Rv5FofBVPn6xm7VxMlK0kg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 49E5A3817A6F; Thu, 11 Aug 2022 19:09:59 +0000 (UTC) Received: from localhost (unknown [10.39.192.120]) by smtp.corp.redhat.com (Postfix) with ESMTP id BD530492C3B; Thu, 11 Aug 2022 19:09:58 +0000 (UTC) Date: Thu, 11 Aug 2022 15:09:57 -0400 From: Stefan Hajnoczi To: Kevin Wolf Cc: qemu-devel@nongnu.org, Alberto Faria , Vladimir Sementsov-Ogievskiy , "Michael S. Tsirkin" , Paolo Bonzini , Laurent Vivier , Eric Blake , sgarzare@redhat.com, Marcel Apfelbaum , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , qemu-block@nongnu.org, Eduardo Habkost , Vladimir Sementsov-Ogievskiy , John Snow , Thomas Huth , Markus Armbruster , Hanna Reitz , Fam Zheng , Yanan Wang , pkrempa@redhat.com Subject: Re: [RFC v3 1/8] blkio: add io_uring block driver using libblkio Message-ID: References: <20220708041737.1768521-1-stefanha@redhat.com> <20220708041737.1768521-2-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="+o9vgjHY/9JccPpf" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" --+o9vgjHY/9JccPpf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 27, 2022 at 09:33:40PM +0200, Kevin Wolf wrote: > Am 08.07.2022 um 06:17 hat Stefan Hajnoczi geschrieben: > > libblkio (https://gitlab.com/libblkio/libblkio/) is a library for > > high-performance disk I/O. It currently supports io_uring and > > virtio-blk-vhost-vdpa with additional drivers under development. > >=20 > > One of the reasons for developing libblkio is that other applications > > besides QEMU can use it. This will be particularly useful for > > vhost-user-blk which applications may wish to use for connecting to > > qemu-storage-daemon. > >=20 > > libblkio also gives us an opportunity to develop in Rust behind a C API > > that is easy to consume from QEMU. > >=20 > > This commit adds io_uring and virtio-blk-vhost-vdpa BlockDrivers to QEMU > > using libblkio. It will be easy to add other libblkio drivers since they > > will share the majority of code. > >=20 > > For now I/O buffers are copied through bounce buffers if the libblkio > > driver requires it. Later commits add an optimization for > > pre-registering guest RAM to avoid bounce buffers. > >=20 > > The syntax is: > >=20 > > --blockdev io_uring,node-name=3Ddrive0,filename=3Dtest.img,readonly= =3Don|off,cache.direct=3Don|off > >=20 > > and: > >=20 > > --blockdev virtio-blk-vhost-vdpa,node-name=3Ddrive0,path=3D/dev/vdpa.= =2E.,readonly=3Don|off > >=20 > > Signed-off-by: Stefan Hajnoczi >=20 > The subject line implies only io_uring, but you actually add vhost-vdpa > support, too. I think the subject line should be changed. >=20 > I think it would also make sense to already implement support for > vhost-user-blk on the QEMU side even if support isn't compiled in > libblkio by default and opening vhost-user-blk images would therefore > always fail with a default build. >=20 > But then you could run QEMU with a custom build of libblkio to make use > of it without patching QEMU. This is probably useful for getting libvirt > support for using a storage daemon implemented without having to wait > for another QEMU release. (Peter, do you have any opinion on this?) vhost-user-blk is now supported in all builds of libblkio. I'll add it. Stefan --+o9vgjHY/9JccPpf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmL1VAUACgkQnKSrs4Gr c8jRPwgAtygtCZJA+ehKG3Cj9WM9Zsg9hU6wNkV2/zThXpZeoYlNXZlJ8Xe7Ed2d NotW/aiNvIfoxdoAMnvu/FoiS/4p1JlMGL9hYbIeCzMit0ujtG1F5QFLD/4Jwd/k Ug0jOBnyXgU6atcaSrgu4k3SL3eTotM0xch/bPaFHGgoXf7MnRE0TFQYqD5Mhv4A V4onWXk6T02czNUOa8GfhMVbKjQEWaT5Z5pDJROQt1r47hK4AIHHmOXlw2dgWwLp rgBahMg2B+SZE9ZpkuQo6KJN8oo7mC9GaMC32nqxBoehU934MePh7gpgUaHenxdJ 1aNlck0XKsTxD8zpBwciILMhp4rf4Q== =OJCF -----END PGP SIGNATURE----- --+o9vgjHY/9JccPpf--