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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 6B11ACCFA13 for ; Wed, 29 Apr 2026 15:26:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B5FED10E3FB; Wed, 29 Apr 2026 15:26:20 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="YQJhuC6W"; dkim-atps=neutral Received: from mail-wm1-f41.google.com (mail-wm1-f41.google.com [209.85.128.41]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4D6EC10E3FB for ; Wed, 29 Apr 2026 15:26:19 +0000 (UTC) Received: by mail-wm1-f41.google.com with SMTP id 5b1f17b1804b1-488b0046078so114871945e9.1 for ; Wed, 29 Apr 2026 08:26:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1777476378; x=1778081178; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=G9kqbgnidQC23bEvrBAVDYa4e7L0vOouqvUY0ysfe8Y=; b=YQJhuC6WO4DCECoPgWYklhrt53tome96fPUjPq0BN4iBTAfICM3gn55fqjZs3HOsdK 2lwJkhIFfJyRpwAFb1mzRrZmjT9makrbgOfW7E8/VU5fI0/zDj63ljB6XhcnkXsa0/RO y0ATGXDRrEjtCQNAvO24cCn6O23FThVGv+Vxh9KlZ21qmsGVnOKlwWzyAlC6octEzg76 rLTjkIWNY6JqYFUDutrD+YJH1sgfqzu9GFT5gnp80Aw7ksP1TWMMoJrwJWmjPAtlLCoT YOHKlN3Igd1hHJPgJXjxny+KJ1IiolrCtXKaCUdbmjXoo4UdzeFk8J72ZzG8jODD89u6 GNhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777476378; x=1778081178; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=G9kqbgnidQC23bEvrBAVDYa4e7L0vOouqvUY0ysfe8Y=; b=kYD1lZcrNx4vGME9F8kHhMp2nWXavq0UicdOUCsDP4H1EmHj/tMRHCWit0jCfAFdI1 ++Bn84wry7NvGqs73Qmf7Wbl0X1GlWKgUqdrncMh0mjKNWnJmZQLQGRdoZOdp/lxmEMy VoNFDVghT3tH7QyYrFDxnSfs2oRFWBDzlhdMAPc+krEWURH5+fCJ5rdWgIGoF20juLFg ycNUcrqX7mxCcvk37JL7YtDvsAXNOA24arMfFNMBNpoQa0EWNsiEZSH7gnhhjFoZNJRi p0ehqs4atpQHIJEZ/fOTxCSL4q+t9VLAW/gfuknvJ0hRhiyP9nI6Jpbo3S0OkOy6ZqJb nqdA== X-Forwarded-Encrypted: i=1; AFNElJ9kzyYxYJ9ZkFlR/mJUuV3kJTfW4HQMSiEvdVQAXLazuMUgoh29yIh6KIHBw7IcuFfjlv/Y1ilAfs0=@lists.freedesktop.org X-Gm-Message-State: AOJu0Yzdep31lOZ+icgepQOFaiqE60yzQvcMrs4HXKqAKBRjz+2EXtTi FiJ2C1NRJrH4PehtBNGa/ZwZ/9s70nNgPVNOHPewQLwy+dPoO1tH8TtT X-Gm-Gg: AeBDietvGMdT9TYV4JPXrY9fnBuQjAbpK3QyAHJd6d7WY1nlKI1GgmS5PwL/KKHX/rI a3ltGicrztaDEZycOvx96NQb4MV9qvRhaUjM9nzrbRN27XhZdwr99JBUSQy1yeKaprDMbaANExD 9J2L2xUel0I8eCKKUdktWwihFzk6lM+U+Jn4PoJP3viSwnWZK1rycL/xvV5uWDgOhdyV6M4oiRr 4IHsQ3sPxml2cQ8EBRQFwa2Lqe0jIh8MxWwLPEVSq6xKtXoJoOQHaajOuX+pYTh7PYVh3PMQ0nS dFgugJw6tdQ3ea+zniwTD4XUL4/2d7h6NJew9hZNPn4Z2oovNWr/BYPdJfEIeKkfc9KiJZYAU3R AOD4sC8U/pP6SxpaTUdAob+fixogAvpRerT4pHrHC6ACzfHdi1VBx0N29P1/OKINJY4GyfsKb9J whacgliM8ZAmI58IrqO2S22FFhfZcds/MBICSadHVLG7+iuvNpmWKgy0NT51+A1UdbP5i26Vy4f FWhV+TCq3WYET9wQYcwRL2KaQuEX5JGWLDB9ypmj/JJ X-Received: by 2002:a05:600c:4f92:b0:489:1ff1:74df with SMTP id 5b1f17b1804b1-48a77ae5430mr125646225e9.1.1777476377153; Wed, 29 Apr 2026 08:26:17 -0700 (PDT) Received: from 127.0.0.1localhost ([82.132.184.31]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-447b76e5c22sm6382951f8f.28.2026.04.29.08.26.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Apr 2026 08:26:16 -0700 (PDT) From: Pavel Begunkov To: Jens Axboe , Keith Busch , Christoph Hellwig , Sagi Grimberg , Alexander Viro , Christian Brauner , Andrew Morton , Sumit Semwal , =?UTF-8?q?Christian=20K=C3=B6nig?= , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Cc: asml.silence@gmail.com, Nitesh Shetty , Kanchan Joshi , Anuj Gupta , Tushar Gohad , William Power , Phil Cayton , Jason Gunthorpe Subject: [PATCH v3 00/10] Add dmabuf read/write via io_uring Date: Wed, 29 Apr 2026 16:25:46 +0100 Message-ID: X-Mailer: git-send-email 2.53.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The patch set allows to register a dmabuf to an io_uring instance for a specified file and use it with io_uring read / write requests. The infrastructure is not tied to io_uring and there could be more users in the future. A similar idea was attempted some years ago by Keith [1], from where I borrowed a good number of changes, and later was brough up by Tushar and Vishal from Intel. It's an opt-in feature for files, and they need to implement a new file operation to use it. Only NVMe block devices are supported in this series. The user API is built on top of io_uring's "registered buffers", where a dmabuf is registered in a special way, but after it can be used as any other "registered buffer" with IORING_OP_{READ,WRITE}_FIXED requests. It's created via a new file operation and the resulted map is then passed through the I/O stack in a new iterator type. There is some additional infrastructure to bind it all, which also counts requests using a dmabuf map and managing lifetimes, which is used to implement map invalidation. It was tested for GPU <-> NVMe transfers. Also, as it maintains a long-term dma mapping, it helps with the IOMMU cost. The numbers below are for udmabuf reads previously run by Anuj for different IOMMU modes: - STRICT: before = 570 KIOPS, after = 5.01 MIOPS - LAZY: before = 1.93 MIOPS, after = 5.01 MIOPS - PASSTHROUGH: before = 5.01 MIOPS, after = 5.01 MIOPS There are some liburing tests that can serve as an example: git: https://github.com/isilence/liburing.git rw-dmabuf-tests-v3 url: https://github.com/isilence/liburing/tree/rw-dmabuf-tests-v3 [1] https://lore.kernel.org/io-uring/20220805162444.3985535-1-kbusch@fb.com/ v3: - Rework io_uring registration - Move token/map infrastructure code out of blk-mq - Simplify callbacks: remove a separate blk-mq table, which was mostly just forwarding calls (to nvme). - Don't skip dma sync depending on request direction - Fix a couple of hangs - Rename s/dma/dmabuf/ - Other small changes v2: - Don't pass raw dma addresses, wrap it into a driver specific object - Split into two objects: token and map - Implement move_notify Pavel Begunkov (10): file: add callback for creating long-term dmabuf maps iov_iter: add iterator type for dmabuf maps block: move bvec init into __bio_clone block: introduce dma map backed bio type lib: add dmabuf token infrastructure block: forward create_dmabuf_token to drivers nvme-pci: implement dma_token backed requests io_uring/rsrc: introduce buf registration structure io_uring/rsrc: extend buffer update io_uring/rsrc: add dmabuf backed registered buffers block/bio.c | 28 +++- block/blk-merge.c | 14 ++ block/blk.h | 3 +- block/fops.c | 16 ++ drivers/nvme/host/pci.c | 282 ++++++++++++++++++++++++++++++++ include/linux/bio.h | 19 ++- include/linux/blk-mq.h | 9 + include/linux/blk_types.h | 8 +- include/linux/fs.h | 2 + include/linux/io_dmabuf_token.h | 92 +++++++++++ include/linux/io_uring_types.h | 5 + include/linux/uio.h | 11 ++ include/uapi/linux/io_uring.h | 31 +++- io_uring/io_uring.c | 3 +- io_uring/rsrc.c | 266 +++++++++++++++++++++++++----- io_uring/rsrc.h | 30 +++- io_uring/rw.c | 4 +- lib/Kconfig | 4 + lib/Makefile | 2 + lib/io_dmabuf_token.c | 272 ++++++++++++++++++++++++++++++ lib/iov_iter.c | 29 +++- 21 files changed, 1071 insertions(+), 59 deletions(-) create mode 100644 include/linux/io_dmabuf_token.h create mode 100644 lib/io_dmabuf_token.c -- 2.53.0