From patchwork Mon Jul 1 06:22:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wu, Hao" X-Patchwork-Id: 11025119 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B978138B for ; Mon, 1 Jul 2019 06:44:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E685284B3 for ; Mon, 1 Jul 2019 06:44:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 21578284E9; Mon, 1 Jul 2019 06:44:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7E990284B3 for ; Mon, 1 Jul 2019 06:44:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727465AbfGAGoL (ORCPT ); Mon, 1 Jul 2019 02:44:11 -0400 Received: from mga07.intel.com ([134.134.136.100]:58897 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727093AbfGAGoL (ORCPT ); Mon, 1 Jul 2019 02:44:11 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Jun 2019 23:39:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,437,1557212400"; d="scan'208";a="361731239" Received: from hao-dev.bj.intel.com ([10.238.157.65]) by fmsmga005.fm.intel.com with ESMTP; 30 Jun 2019 23:39:00 -0700 From: Wu Hao To: mdf@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-api@vger.kernel.org, gregkh@linuxfoundation.org, atull@kernel.org, Wu Hao , Xu Yilun Subject: [PATCH v2 05/15] Documentation: fpga: dfl: add descriptions for virtualization and new interfaces. Date: Mon, 1 Jul 2019 14:22:12 +0800 Message-Id: <1561962132-3782-1-git-send-email-hao.wu@intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-fpga-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- v2: fix issues during rebasing (doc format change txt -> rst). --- 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