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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BFDAC7619A for ; Tue, 23 Jul 2019 05:10:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6126B2238C for ; Tue, 23 Jul 2019 05:10:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732956AbfGWFKV (ORCPT ); Tue, 23 Jul 2019 01:10:21 -0400 Received: from mga05.intel.com ([192.55.52.43]:1868 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727735AbfGWFKU (ORCPT ); Tue, 23 Jul 2019 01:10:20 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Jul 2019 22:10:19 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,297,1559545200"; d="scan'208";a="196992413" Received: from hao-dev.bj.intel.com ([10.238.157.65]) by fmsmga002.fm.intel.com with ESMTP; 22 Jul 2019 22:10:17 -0700 From: Wu Hao To: gregkh@linuxfoundation.org, mdf@kernel.org, linux-fpga@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, atull@kernel.org, Wu Hao , Xu Yilun Subject: [PATCH v3 12/12] Documentation: fpga: dfl: add descriptions for virtualization and new interfaces. Date: Tue, 23 Jul 2019 12:51:35 +0800 Message-Id: <1563857495-26692-13-git-send-email-hao.wu@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1563857495-26692-1-git-send-email-hao.wu@intel.com> References: <1563857495-26692-1-git-send-email-hao.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds virtualization support description for DFL based FPGA devices (based on PCIe SRIOV), and introductions to new interfaces added by new dfl private feature drivers. [mdf@kernel.org: Fixed up to make it work with new reStructuredText docs] Signed-off-by: Xu Yilun Signed-off-by: Wu Hao Acked-by: Alan Tull Signed-off-by: Moritz Fischer --- Documentation/fpga/dfl.rst | 105 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst index 2f125ab..6fa483f 100644 --- a/Documentation/fpga/dfl.rst +++ b/Documentation/fpga/dfl.rst @@ -87,6 +87,8 @@ The following functions are exposed through ioctls: - Get driver API version (DFL_FPGA_GET_API_VERSION) - Check for extensions (DFL_FPGA_CHECK_EXTENSION) - Program bitstream (DFL_FPGA_FME_PORT_PR) +- Assign port to PF (DFL_FPGA_FME_PORT_ASSIGN) +- Release port from PF (DFL_FPGA_FME_PORT_RELEASE) More functions are exposed through sysfs (/sys/class/fpga_region/regionX/dfl-fme.n/): @@ -102,6 +104,10 @@ More functions are exposed through sysfs one FPGA device may have more than one port, this sysfs interface indicates how many ports the FPGA device has. + Global error reporting management (errors/) + error reporting sysfs interfaces allow user to read errors detected by the + hardware, and clear the logged errors. + FIU - PORT ========== @@ -143,6 +149,10 @@ More functions are exposed through sysfs: Read Accelerator GUID (afu_id) afu_id indicates which PR bitstream is programmed to this AFU. + Error reporting (errors/) + error reporting sysfs interfaces allow user to read port/afu errors + detected by the hardware, and clear the logged errors. + DFL Framework Overview ====================== @@ -218,6 +228,101 @@ the compat_id exposed by the target FPGA region. This check is usually done by userspace before calling the reconfiguration IOCTL. +FPGA virtualization - PCIe SRIOV +================================ +This section describes the virtualization support on DFL based FPGA device to +enable accessing an accelerator from applications running in a virtual machine +(VM). This section only describes the PCIe based FPGA device with SRIOV support. + +Features supported by the particular FPGA device are exposed through Device +Feature Lists, as illustrated below: + +:: + + +-------------------------------+ +-------------+ + | PF | | VF | + +-------------------------------+ +-------------+ + ^ ^ ^ ^ + | | | | + +-----|------------|---------|--------------|-------+ + | | | | | | + | +-----+ +-------+ +-------+ +-------+ | + | | FME | | Port0 | | Port1 | | Port2 | | + | +-----+ +-------+ +-------+ +-------+ | + | ^ ^ ^ | + | | | | | + | +-------+ +------+ +-------+ | + | | AFU | | AFU | | AFU | | + | +-------+ +------+ +-------+ | + | | + | DFL based FPGA PCIe Device | + +---------------------------------------------------+ + +FME is always accessed through the physical function (PF). + +Ports (and related AFUs) are accessed via PF by default, but could be exposed +through virtual function (VF) devices via PCIe SRIOV. Each VF only contains +1 Port and 1 AFU for isolation. Users could assign individual VFs (accelerators) +created via PCIe SRIOV interface, to virtual machines. + +The driver organization in virtualization case is illustrated below: +:: + + +-------++------++------+ | + | FME || FME || FME | | + | FPGA || FPGA || FPGA | | + |Manager||Bridge||Region| | + +-------++------++------+ | + +-----------------------+ +--------+ | +--------+ + | FME | | AFU | | | AFU | + | Module | | Module | | | Module | + +-----------------------+ +--------+ | +--------+ + +-----------------------+ | +-----------------------+ + | FPGA Container Device | | | FPGA Container Device | + | (FPGA Base Region) | | | (FPGA Base Region) | + +-----------------------+ | +-----------------------+ + +------------------+ | +------------------+ + | FPGA PCIE Module | | Virtual | FPGA PCIE Module | + +------------------+ Host | Machine +------------------+ + -------------------------------------- | ------------------------------ + +---------------+ | +---------------+ + | PCI PF Device | | | PCI VF Device | + +---------------+ | +---------------+ + +FPGA PCIe device driver is always loaded first once a FPGA PCIe PF or VF device +is detected. It: + +* Finishes enumeration on both FPGA PCIe PF and VF device using common + interfaces from DFL framework. +* Supports SRIOV. + +The FME device driver plays a management role in this driver architecture, it +provides ioctls to release Port from PF and assign Port to PF. After release +a port from PF, then it's safe to expose this port through a VF via PCIe SRIOV +sysfs interface. + +To enable accessing an accelerator from applications running in a VM, the +respective AFU's port needs to be assigned to a VF using the following steps: + +#. The PF owns all AFU ports by default. Any port that needs to be + reassigned to a VF must first be released through the + DFL_FPGA_FME_PORT_RELEASE ioctl on the FME device. + +#. Once N ports are released from PF, then user can use command below + to enable SRIOV and VFs. Each VF owns only one Port with AFU. + + :: + + echo N > $PCI_DEVICE_PATH/sriov_numvfs + +#. Pass through the VFs to VMs + +#. The AFU under VF is accessible from applications in VM (using the + same driver inside the VF). + +Note that an FME can't be assigned to a VF, thus PR and other management +functions are only available via the PF. + Device enumeration ================== This section introduces how applications enumerate the fpga device from -- 1.8.3.1