From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 1101248A03; Tue, 28 Oct 2025 17:43:32 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 7508C4028D; Tue, 28 Oct 2025 17:43:31 +0100 (CET) Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) by mails.dpdk.org (Postfix) with ESMTP id 3202C4021E for ; Tue, 28 Oct 2025 17:43:29 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761669809; x=1793205809; h=from:to:subject:date:message-id:mime-version: content-transfer-encoding; bh=aYOLC6KO+u8zbCAgRHLTEeZfnCY4RPh3qNLwMhwAbFg=; b=OzBo8NaO8YnCVPYl2P9yX3liLEWdaV6xle3HXBv7ouh+2sTnmRKQK+7D A2hif6kYr7M9ha6uhMwShDE86KampnLCDfaESxxJMVLSdTu04jrT4H8il gd2OU94u1CK72NpyV7FTZZgkOSt8aQzK+d3S+oKr++aZ0GdrY4budyvv9 ZzKVEeSDKPvRbc+AdRtu0f9MJnJ4/pcdVVibUmeP5PLpQOAzvBLU83llF y8quvT5Eaqw+eaYidom9BWQFp8M/lYb9IIf+D/TRUpmNc6HQcApokIHv+ Fo//+8uG/WGH3aPBOLcygEKJ+s/zpTq3wtIjHkhWv63hmxXScB/KhcFXV Q==; X-CSE-ConnectionGUID: TunpVJllTmuMZ+yBd5pIDQ== X-CSE-MsgGUID: 5Uv7wtmmTP6Tcuk1xTi03A== X-IronPort-AV: E=McAfee;i="6800,10657,11586"; a="63663615" X-IronPort-AV: E=Sophos;i="6.19,261,1754982000"; d="scan'208";a="63663615" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2025 09:43:28 -0700 X-CSE-ConnectionGUID: inXYfGJwT8KCrXoGGek1SA== X-CSE-MsgGUID: Ng9D6t2tS5yzNvkWuhQ+ZQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,261,1754982000"; d="scan'208";a="189452743" Received: from silpixa00401119.ir.intel.com ([10.20.224.206]) by orviesa003.jf.intel.com with ESMTP; 28 Oct 2025 09:43:27 -0700 From: Anatoly Burakov To: dev@dpdk.org Subject: [PATCH v1 0/8] Support VFIO cdev API in DPDK Date: Tue, 28 Oct 2025 16:43:13 +0000 Message-ID: X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org This patchset introduces a major refactor of the VFIO subsystem in DPDK to support character device (cdev) interface introduced in Linux kernel, as well as make the API more streamlined and useful. The goal is to simplify device management, improve compatibility, and clarify API responsibilities. The following sections outline the key issues addressed by this patchset and the corresponding changes introduced. 1. Only group mode is supported =============================== Since kernel version 4.14.327 (LTS), VFIO supports the new character device (cdev)-based way of working with VFIO devices (otherwise known as IOMMUFD). This is a device-centric mode and does away with all the complexity regarding groups and IOMMU types, delegating it all to the kernel, and exposes a much simpler interface to userspace. The old group interface is still around, and will need to be kept in DPDK both for compatibility reasons, as well as supporting special cases (FSLMC bus, NBL driver, etc.). To enable this, VFIO is heavily refactored, so that the code can support both modes while relying on (mostly) common infrastructure. Note that the existing `rte_vfio_device_setup/release` model is fundamentally incompatible with cdev mode, because for custom container cases, the expected flow is that the user binds the IOMMU group (and thus, implicitly, the device itself) to a specific container using `rte_vfio_container_group_bind`, whereas this step is not needed for cdev as the device fd is assigned to the container straight away. Therefore, what we do instead is introduce a new API for container device assignment which, semantically, will assign a device to specified container, so that when it is mapped using `rte_pci_map_device`, the appropriate container is selected. Under the hood though, we essentially transition to getting device fd straight away at assign stage, so that by the time the PCI bus attempts to map the device, it is already mapped and we just return an fd. Additionally, a new `rte_vfio_get_mode` API is added for those cases that need some introspection into VFIO's internals, with three new modes: group (old-style), no-iommu (old-style but without IOMMU), and cdev (the new mode). Although no-IOMMU is technically a variant of group mode, the distinction is largely irrelevant to the user, as all usages of noiommu checks in our codebase are for deciding whether to use IOVA or PA, not anything to do with managing groups. The current plan for kernel community is to *not* introduce no-IOMMU cdev implementation, which is why this will be kept for compatibility for these use cases. As for special cases that rely on group mode, the old group-based API calls are kept, but will be marked as deprecated, and will only work in group/noiommu mode. This has little practical consequences, as even users such as NBL or FSLMC bus do not actually use any of VFIO functionality, they just create a container and proceed to do their own thing. 2. There is duplication among API's =================================== Over time, several VFIO API's have been added that perform overlapping functions: * `rte_vfio_get_group_fd` does the same thing as `rte_vfio_container_group_bind` * `rte_vfio_clear_group` does the same thing as rte_vfio_container_group_unbind` The only difference between them is that for the former API's, the container selection is implicit (create in default if doesn't exist, delete from any container). It really only makes sense to keep container versions around, but because we don't really need any of them any more, all of them will be deprecated. 3. The API responsibilities aren't clear and bleed into each other ================================================================== Some API's do multiple things at once. In particular: * `rte_vfio_get_group_fd` opens a new group if it doesn't exist * `rte_vfio_container_group_bind/unbind` return group fd * `rte_vfio_get_device_info` will setup the device These API's have been adjusted as follows: * `rte_vfio_get_group_fd` will *not* open any fd's, it will *only* return those previously bound to a container by `rte_vfio_container_group_bind` * `rte_vfio_container_group_bind` will *not* return any fd's (users should call `rte_vfio_get_group_fd` to get it) * `rte_vfio_get_device_info` will *not* set up the device (users should call `rte_vfio_container_device_setup` prior to calling this API) All current users of these API's were adjusted, and grou-related API's were marked as deprecated. Feedback and suggestions are welcome, especially from maintainers of drivers that depend on VFIO infrastructure. Anatoly Burakov (8): uapi: update to v6.17 and add iommufd.h vfio: add container device assignment API vhost: remove group-related API from drivers vfio: do not setup the device on get device info vfio: cleanup and refactor vfio: introduce cdev mode doc: deprecate VFIO group-based APIs vfio: deprecate group-based API config/arm/meson.build | 1 + config/meson.build | 1 + doc/guides/rel_notes/deprecation.rst | 26 + drivers/bus/cdx/cdx_vfio.c | 13 +- drivers/bus/fslmc/fslmc_bus.c | 10 +- drivers/bus/fslmc/fslmc_vfio.c | 2 +- drivers/bus/pci/linux/pci.c | 2 +- drivers/bus/pci/linux/pci_vfio.c | 17 +- drivers/crypto/bcmfs/bcmfs_vfio.c | 6 +- drivers/net/hinic3/base/hinic3_hwdev.c | 2 +- drivers/net/nbl/nbl_common/nbl_userdev.c | 18 +- drivers/net/nbl/nbl_include/nbl_include.h | 1 + drivers/net/ntnic/ntnic_ethdev.c | 2 +- drivers/net/ntnic/ntnic_vfio.c | 30 +- drivers/vdpa/ifc/ifcvf_vdpa.c | 34 +- drivers/vdpa/mlx5/mlx5_vdpa.c | 1 - drivers/vdpa/nfp/nfp_vdpa.c | 37 +- drivers/vdpa/sfc/sfc_vdpa.c | 39 +- drivers/vdpa/sfc/sfc_vdpa.h | 2 - kernel/linux/uapi/linux/iommufd.h | 1292 ++++++++++ kernel/linux/uapi/linux/vduse.h | 2 +- kernel/linux/uapi/linux/vfio.h | 12 +- kernel/linux/uapi/version | 2 +- lib/eal/freebsd/eal.c | 36 + lib/eal/include/rte_vfio.h | 414 +++- lib/eal/linux/eal_vfio.c | 2640 +++++++++------------ lib/eal/linux/eal_vfio.h | 170 +- lib/eal/linux/eal_vfio_cdev.c | 387 +++ lib/eal/linux/eal_vfio_group.c | 981 ++++++++ lib/eal/linux/eal_vfio_mp_sync.c | 91 +- lib/eal/linux/meson.build | 2 + lib/vhost/vdpa_driver.h | 3 - 32 files changed, 4484 insertions(+), 1792 deletions(-) create mode 100644 kernel/linux/uapi/linux/iommufd.h create mode 100644 lib/eal/linux/eal_vfio_cdev.c create mode 100644 lib/eal/linux/eal_vfio_group.c -- 2.47.3