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=-7.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 5C03BC11F66 for ; Tue, 29 Jun 2021 04:13:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40A1E61CC7 for ; Tue, 29 Jun 2021 04:13:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231462AbhF2EPk (ORCPT ); Tue, 29 Jun 2021 00:15:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53787 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229562AbhF2EPj (ORCPT ); Tue, 29 Jun 2021 00:15:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624939992; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7N6S5aXlTsxjRnLUAwuT1GGB2dsJH/gvDpQ3UzIqM0M=; b=SzUh/i8W2tjOYdKVVA/eEfddfMy1StTwJiTZYSj8HAtZ68CiWJ874FtLqq+cdtz+G0LEXY vkI1Z7GBb5PCxfQwmWZ6uZGDH2stkTWWqiZT4Su5U3MaKm7lK7PwFtdxziuC9eW84yu2Z9 hfBlLce79yj+OthZpYL/4Tk8tdmefIw= Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-325-8pK7UFR_MRmNSv6HWDvWBA-1; Tue, 29 Jun 2021 00:13:08 -0400 X-MC-Unique: 8pK7UFR_MRmNSv6HWDvWBA-1 Received: by mail-pj1-f71.google.com with SMTP id go14-20020a17090b03ceb02901709d30a8a1so1389930pjb.5 for ; Mon, 28 Jun 2021 21:13:08 -0700 (PDT) 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=7N6S5aXlTsxjRnLUAwuT1GGB2dsJH/gvDpQ3UzIqM0M=; b=nYAnkZF3F74MdaZ5NhJfxvBxv/heVqdNaXkW11m4o0CHIxQzE5SnMdLwv6h0B3AoqV nMMRGGDbExq8aVu6u7lHrGMcjKV/VSesp2rK1m2Bs4/v3bSxfMmtiyEYu1bQG/Iknp0p whaUhriUMZONUeA8BGSomuFtqvPcfUO+Bz7W1oLL1fkqXtSsz8ODvEkoqFwURYhNFhrZ xlLEVAzw2d1hkfTgm0ZIFqCBnGPvfBnc1M+IoRdb+XKy8YY1bkoWkio2s0E11C2fo7yn 4b0AkRrZd3mVOhMaIBI1JACbipR2p5iZNJ/C5U0RNDsEaH1p6oBUYKfW7AFU/Y/q7VLa jV2w== X-Gm-Message-State: AOAM530XlFkrpdKltuOHFEJ/2n+60jGibgSeOaAsy6GgHe/wOC3viAhN 8saQ/WHCmRwCuc/jK111S+wTBLwTIGSDuJz9mPuNPQw++8y/idk3JrF6rCo1JX0/5sEQ6NNNNeO VpIfniTYq8TJCwkwe1W040Ywg X-Received: by 2002:a65:478d:: with SMTP id e13mr26587079pgs.37.1624939987923; Mon, 28 Jun 2021 21:13:07 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxTnV+jCJcWth5Gh1PanbNwyDV44mMvsm0eLCzSFKGOg12/3H6rwksZzo35n3QJumwiuRcZHQ== X-Received: by 2002:a65:478d:: with SMTP id e13mr26587053pgs.37.1624939987713; Mon, 28 Jun 2021 21:13:07 -0700 (PDT) Received: from wangxiaodeMacBook-Air.local ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id k13sm1525904pgh.82.2021.06.28.21.12.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Jun 2021 21:13:07 -0700 (PDT) Subject: Re: [PATCH v8 00/10] Introduce VDUSE - vDPA Device in Userspace To: Yongji Xie , Liu Xiaodong Cc: Xie Yongji , "Michael S. Tsirkin" , Stefan Hajnoczi , sgarzare@redhat.com, parav@nvidia.com, hch@infradead.org, christian.brauner@canonical.com, rdunlap@infradead.org, willy@infradead.org, viro@zeniv.linux.org.uk, axboe@kernel.dk, bcrl@kvack.org, corbet@lwn.net, mika.penttila@nextfour.com, dan.carpenter@oracle.com, joro@8bytes.org, gregkh@linuxfoundation.org, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, iommu@lists.linux-foundation.org, songmuchun@bytedance.com, linux-fsdevel@vger.kernel.org References: <20210615141331.407-1-xieyongji@bytedance.com> <20210628103309.GA205554@storage2.sh.intel.com> From: Jason Wang Message-ID: Date: Tue, 29 Jun 2021 12:12:57 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2021/6/28 下午6:32, Yongji Xie 写道: >> The large barrier is bounce-buffer mapping: SPDK requires hugepages >> for NVMe over PCIe and RDMA, so take some preallcoated hugepages to >> map as bounce buffer is necessary. Or it's hard to avoid an extra >> memcpy from bounce-buffer to hugepage. >> If you can add an option to map hugepages as bounce-buffer, >> then SPDK could also be a potential user of vduse. >> > I think we can support registering user space memory for bounce-buffer > use like XDP does. But this needs to pin the pages, so I didn't > consider it in this initial version. > Note that userspace should be unaware of the existence of the bounce buffer. So we need to think carefully of mmap() vs umem registering. Thanks