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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 70969C46471 for ; Wed, 8 Aug 2018 01:43:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 292C72172B for ; Wed, 8 Aug 2018 01:43:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YYvsBA/Z" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 292C72172B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727025AbeHHEAa (ORCPT ); Wed, 8 Aug 2018 00:00:30 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:34760 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725139AbeHHEA3 (ORCPT ); Wed, 8 Aug 2018 00:00:29 -0400 Received: by mail-pg1-f193.google.com with SMTP id y5-v6so298090pgv.1; Tue, 07 Aug 2018 18:43:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=AB7TcnrV6LXzlQCIIWkyJVsv0fQHvbuoT4YfobIhaLU=; b=YYvsBA/ZWXUQCKfnDD2tOv8uFvoz4QSSHCX1RvRMdBQCMZz+7b8UTVLjH8u7D9o1Rn MF9X3yQzWu4EV0Zk28U80Y0A3TdAEO/cl9wZ3mTSiY4ABGMvBvBiXgvBoNM2/3q/MVgA dDggauCS4aMJzvZY4uZPWDgRXXeS53sOYMkZlqhJXZliMd4pCxtz4CKtmPGHVRj2DC+X RxETc6DbeaWhAIvd7FMjzkWaDKKJlTFW1NoM7YNn24ya8G1LolOxue85sDcvYWM8ZY79 LrGDbWH8DXn4PCkbR4p18SfeaxhfNtVuLDQs8fSA5BCdXK9AduSxRDQl4Wto2IUDqoDm MO4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=AB7TcnrV6LXzlQCIIWkyJVsv0fQHvbuoT4YfobIhaLU=; b=dJ/+dl5AggM0LQSvCxK524mBAIs45kjYTWq3rOObMY4CfWYyP7Ct1rHrtkJThlTD6i V02iY4Ej1qlVqdd9Hu9PnYoX9kGzEoH7VMGC4qVyH8e83YrltFdByCE4fYdDbSMHzCbE kOuovCL842iAHtP8gNNA1fVTS4TViErdk1YKugfnEegDf/18vusvHki/ZEH6N2N4SwTp 220HSmhoURWlQ0z7vYRQQ6HgIiEThJ8aW9uNIbycGCf7p7ohWm4yi0HdjVEZ/XCyHi67 PUAkNiOX+PzG7wQKgH0BFWkEJ6GAuVKmuF2QCmWadgq4t6mka2XWqIPV1NwOh+6NP7Jq CtCQ== X-Gm-Message-State: AOUpUlEbNsoU8X/0L9RV4kLQB1dlwGGJ/SfJqjRXGLbLaUXl7fw1zY48 MkqmKDDtbEZa9y2emBwVrV8= X-Google-Smtp-Source: AA+uWPwNrDa2O4Rb4PFuqQAyQ8h5YqIc+XtzFN57mslVxCgd/Z9X8z3QoUvbgpzjOrXvYVhxFLV65g== X-Received: by 2002:a62:1b4a:: with SMTP id b71-v6mr710884pfb.221.1533692598336; Tue, 07 Aug 2018 18:43:18 -0700 (PDT) Received: from [10.66.0.122] ([104.207.83.31]) by smtp.gmail.com with ESMTPSA id z19-v6sm2965538pgi.33.2018.08.07.18.43.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Aug 2018 18:43:17 -0700 (PDT) Subject: Re: [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework To: Pavel Machek Cc: Jonathan Corbet , Herbert Xu , "David S . Miller" , Joerg Roedel , Alex Williamson , Kenneth Lee , Hao Fang , Zhou Wang , Zaibo Xu , Philippe Ombredanne , Greg Kroah-Hartman , Thomas Gleixner , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-accelerators@lists.ozlabs.org, Lu Baolu , Sanjay Kumar , linuxarm@huawei.com References: <20180801102221.5308-1-nek.in.cn@gmail.com> <20180801102221.5308-2-nek.in.cn@gmail.com> <20180806122733.GA17232@xo-6d-61-c0.localdomain> From: Kenneth Lee Message-ID: <7977ce04-35db-92b4-71b8-54a31484ef0b@gmail.com> Date: Wed, 8 Aug 2018 09:43:05 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180806122733.GA17232@xo-6d-61-c0.localdomain> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2018年08月06日 星期一 08:27 下午, Pavel Machek 写道: > Hi! > >> WarpDrive is a common user space accelerator framework. Its main component >> in Kernel is called spimdev, Share Parent IOMMU Mediated Device. It exposes > spimdev is really unfortunate name. It looks like it has something to do with SPI, but > it does not. > Yes. Let me change it to Share (IOMMU) Domain MDev, SDMdev:) >> +++ b/Documentation/warpdrive/warpdrive.rst >> @@ -0,0 +1,153 @@ >> +Introduction of WarpDrive >> +========================= >> + >> +*WarpDrive* is a general accelerator framework built on top of vfio. >> +It can be taken as a light weight virtual function, which you can use without >> +*SR-IOV* like facility and can be shared among multiple processes. >> + >> +It can be used as the quick channel for accelerators, network adaptors or >> +other hardware in user space. It can make some implementation simpler. E.g. >> +you can reuse most of the *netdev* driver and just share some ring buffer to >> +the user space driver for *DPDK* or *ODP*. Or you can combine the RSA >> +accelerator with the *netdev* in the user space as a Web reversed proxy, etc. > What is DPDK? ODP? DPDK：https://www.dpdk.org/about/ ODP: https://www.opendataplane.org/ will add the reference in the next RFC > >> +How does it work >> +================ >> + >> +*WarpDrive* takes the Hardware Accelerator as a heterogeneous processor which >> +can share some load for the CPU: >> + >> +.. image:: wd.svg >> + :alt: This is a .svg image, if your browser cannot show it, >> + try to download and view it locally >> + >> +So it provides the capability to the user application to: >> + >> +1. Send request to the hardware >> +2. Share memory with the application and other accelerators >> + >> +These requirements can be fulfilled by VFIO if the accelerator can serve each >> +application with a separated Virtual Function. But a *SR-IOV* like VF (we will >> +call it *HVF* hereinafter) design is too heavy for the accelerator which >> +service thousands of processes. > VFIO? VF? HVF? > > Also "gup" might be worth spelling out. But I think the reference [1] has explained this. > >> +References >> +========== >> +.. [1] Accroding to the comment in in mm/gup.c, The *gup* is only safe within >> + a syscall. Because it can only keep the physical memory in place >> + without making sure the VMA will always point to it. Maybe we should >> + raise the VM_PINNED patchset (see >> + https://lists.gt.net/linux/kernel/1931993) again to solve this probl > > I went through the docs, but I still don't know what it does. Will refine the doc in next RFC, hope it will help. > Pavel >