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 B30DBC87FC5 for ; Mon, 21 Jul 2025 12:40:28 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1udpnp-0005gw-2P; Mon, 21 Jul 2025 08:39:33 -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 1udpnj-0005E1-VE for qemu-devel@nongnu.org; Mon, 21 Jul 2025 08:39:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1udpng-0004FN-A6 for qemu-devel@nongnu.org; Mon, 21 Jul 2025 08:39:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753101563; 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=zAB20DBaGxbXTmz/aKytmtD2+yIyNSGFc2uCLnWbDpE=; b=HpKH8IcvcbbzeMb20n+WRYwys5OzVTBiqeH1TvuOd1FYq16AaM6PTtKFaWwFn9hgrwM4rT tgM8LNnq60IPbkjoqanj9jXP3/Z5rOgUdaKRkkw8nPkhS2qCwo/6XR1OCjlAoKGBpJ+nSE d9c3Xflvj9T5ya66+C3y44ShB7FpH+w= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-141-7t5rM-F9MjezYkU9O0G7wg-1; Mon, 21 Jul 2025 08:39:19 -0400 X-MC-Unique: 7t5rM-F9MjezYkU9O0G7wg-1 X-Mimecast-MFC-AGG-ID: 7t5rM-F9MjezYkU9O0G7wg_1753101558 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 639FC195FD2B; Mon, 21 Jul 2025 12:39:18 +0000 (UTC) Received: from localhost (unknown [10.2.16.31]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 6E68719560A3; Mon, 21 Jul 2025 12:39:17 +0000 (UTC) Date: Sun, 20 Jul 2025 12:13:51 -0400 From: Stefan Hajnoczi To: Brian Song Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, armbru@redhat.com, bschubert@ddn.com, fam@euphon.net, hreitz@redhat.com, kwolf@redhat.com Subject: Re: [PATCH RFC 0/1] block/export: FUSE-over-io_uring Support for QEMU FUSE Exports Message-ID: <20250720161351.GA32887@fedora> References: <20250716183824.216257-1-hibriansong@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="SezE4twLgtxkGkmM" Content-Disposition: inline In-Reply-To: <20250716183824.216257-1-hibriansong@gmail.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DATE_IN_PAST_12_24=1.049, DKIMWL_WL_HIGH=-0.926, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable 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 --SezE4twLgtxkGkmM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 16, 2025 at 02:38:23PM -0400, Brian Song wrote: > This RFC patch represents an initial implementation of the FUSE-over-=20 > io_uring Exports idea proposed for Google Summer of Code (2025) under=20 > the QEMU community: > https://wiki.qemu.org/Google_Summer_of_Code_2025#FUSE-over-io_uring_expor= ts >=20 > The implementation approach is primarily borrowed from how libfuse=20 > interacts with the kernel. >=20 > FUSE-over-io_uring (https://docs.kernel.org/next/filesystems/fuse-io-=20 > uring.html) has been officially merged into the Linux kernel. The idea=20 > is to replace the traditional /dev/fuse based communication with a more= =20 > efficient io_uring-based approach. In this model, userspace registers=20 > io_uring SQEs via the FUSE_IO_URING_CMD_REGISTER opcode, and then waits= =20 > for the kernel to forward FUSE requests as CQEs. These are processed by= =20 > the FUSE exports implementation in userspace and then committed back to= =20 > the kernel using FUSE_IO_URING_CMD_COMMIT_AND_FETCH. >=20 > To enable this feature in qemu-export-daemon, simply add the uring=3Don= =20 > option to the export configuration. For consistency with the --blockdev file,aio=3Dio_uring option, please name it "io_uring=3Don" instead of "uring=3Don". >=20 > As this patch is still in the RFC stage, it currently supports **only=20 > single thread**. Due to protocol requirements in FUSE-over-io_uring, > the number of FUSE threads must match the number of CPUs. Therefore, > this initial version only works on single-core VMs (i.e., QEMU started > with -smp 1) or single core machine. >=20 > Brian Song (1): > block/export: FUSE-over-io_uring Support for QEMU FUSE Exports >=20 > block/export/fuse.c | 423 +++++++++++++++++++++++++-- > docs/tools/qemu-storage-daemon.rst | 10 +- > qapi/block-export.json | 6 +- > storage-daemon/qemu-storage-daemon.c | 1 + > util/fdmon-io_uring.c | 5 +- > 5 files changed, 420 insertions(+), 25 deletions(-) >=20 > --=20 > 2.50.1 >=20 --SezE4twLgtxkGkmM Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmh9Fb4ACgkQnKSrs4Gr c8ioUAf+NdtbezyiQ6w0MzegtZyDJ5LSzEQQ/wRwIKqDs+Z1UR4p/Hp6m/NxAiLz PYvMyYEIgeir49wHVxcOYj677Rj2wl8BVX9E9553AfZhajDDu7uDIo+s4Ci0YIWk qYcZcTYHtOzlE3rTSY/IEmjgtgv0ebRhpPOHYevvSVxG0Ao0jviHGLT8jB+50Ob1 sGzNXd7bNhyjKk4KIgkrfMvgCIy5oSge6Ko1Ehr1MY1PvMVP9JcYZentt1Lvf4Rx 3wwE6SCFf3iDpai3YQEMv/qAyfoeUvGZEvt0kp+MuN7vzuUAxRwPYkJma1409teh DMJVN93QVo4DgJRCeEZ4a66SeVdIIQ== =MVNo -----END PGP SIGNATURE----- --SezE4twLgtxkGkmM--