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 F3488C83F1A for ; Tue, 22 Jul 2025 14:50:51 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ueEK4-0001XW-Vh; Tue, 22 Jul 2025 10:50:29 -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 1ueEHH-0007be-Fv for qemu-devel@nongnu.org; Tue, 22 Jul 2025 10:47:39 -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 1ueEHF-0003oh-Gt for qemu-devel@nongnu.org; Tue, 22 Jul 2025 10:47:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753195651; 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=V21aGfgtRedGK4eXZ9WWzEfFrJCE0djBbVWpDfpgI70=; b=HqHTjWDUnCzEM9EoDRH43IVxMh45wTQqJx7h90PedOTy7jWZwb8eAK/S3QpdOqxHEghm9i XqMFpMpUX7U0JCyYRK8dfucQK08F5R3cPyH9ZkE5g3MtzW99djSepQaM8NeXn6udwTWwva deQZfOrE318FC8ht7JfWwbMbSguwpaA= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-681-ie_8FI_bM0KmqqnZvJPqeg-1; Tue, 22 Jul 2025 10:47:26 -0400 X-MC-Unique: ie_8FI_bM0KmqqnZvJPqeg-1 X-Mimecast-MFC-AGG-ID: ie_8FI_bM0KmqqnZvJPqeg_1753195645 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0482E1800343; Tue, 22 Jul 2025 14:47:25 +0000 (UTC) Received: from localhost (unknown [10.2.16.72]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2A56418002AF; Tue, 22 Jul 2025 14:47:23 +0000 (UTC) Date: Tue, 22 Jul 2025 10:47:22 -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: <20250722144722.GD8264@fedora> References: <20250716183824.216257-1-hibriansong@gmail.com> <20250720161351.GA32887@fedora> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="bNkonkB4NXCTuVVZ" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 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: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.633, 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_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_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 --bNkonkB4NXCTuVVZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 22, 2025 at 08:00:00AM -0400, Brian Song wrote: > On 7/20/25 12:13 PM, Stefan Hajnoczi wrote: > > On Wed, Jul 16, 2025 at 02:38:23PM -0400, Brian Song wrote: > >> This RFC patch represents an initial implementation of the FUSE-over- > >> io_uring Exports idea proposed for Google Summer of Code (2025) under > >> the QEMU community: > >> https://wiki.qemu.org/Google_Summer_of_Code_2025#FUSE-over-io_uring_ex= ports > >> > >> The implementation approach is primarily borrowed from how libfuse > >> interacts with the kernel. > >> > >> FUSE-over-io_uring (https://docs.kernel.org/next/filesystems/fuse-io- > >> uring.html) has been officially merged into the Linux kernel. The idea > >> is to replace the traditional /dev/fuse based communication with a more > >> efficient io_uring-based approach. In this model, userspace registers > >> io_uring SQEs via the FUSE_IO_URING_CMD_REGISTER opcode, and then waits > >> for the kernel to forward FUSE requests as CQEs. These are processed by > >> the FUSE exports implementation in userspace and then committed back to > >> the kernel using FUSE_IO_URING_CMD_COMMIT_AND_FETCH. > >> > >> To enable this feature in qemu-export-daemon, simply add the uring=3Don > >> 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 > It seems we are not allowed to use '_' here. >=20 > In file included from ../storage-daemon/qapi/qapi-schema.json:57: >=20 > ../storage-daemon/qapi/../../qapi/block-export.json: In struct > 'BlockExportOptionsFuse': >=20 > ../storage-daemon/qapi/../../qapi/block-export.json:191: name of 'data' > member '*io_uring' must not use uppercase or '_' Then "-" is fine, but please use "iouring" so it is as close as possible (not "uring", "iouring", etc). Thanks, Stefan >=20 >=20 > >> > >> As this patch is still in the RFC stage, it currently supports **only > >> 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. > >> > >> Brian Song (1): > >> block/export: FUSE-over-io_uring Support for QEMU FUSE Exports > >> > >> 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(-) > >> > >> -- > >> 2.50.1 > >> >=20 --bNkonkB4NXCTuVVZ Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmh/pHoACgkQnKSrs4Gr c8gpWggAw5oNXutaeu6TLIyUCGiQcBmK+6z3VJ52QBwLEbocoXk1i2o21FkRFO8h p+9Hkw2KVi0Yb+BM446PMyHtVmx5n1SeZrlWyTXRe0VIC4XTJ6/qU8Fq3xwS8zyh ypZzzJSMs6N99NkXy9UbDJf9JLfbsBjqmjnvFIKNLauRkb8yCgNk9+lsOh0h2rq/ BETf7w3ZREh27DFZA9BV8uJb0KgA/QYgrNCvBusFnEQaXLEi5nd+S42l0S2kLqf/ wtaI+3a0sAK/beKQws0p6SGw5Rz9W+PiXN0c2SMomhrSbkhvN7I/tgq0VM3Snv4y Mmcy+rlIRqnmorR0Zt0PSabqWdb3ZQ== =fbcV -----END PGP SIGNATURE----- --bNkonkB4NXCTuVVZ--