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=-19.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 7A3BFC433E9 for ; Wed, 23 Dec 2020 06:40:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25D7222517 for ; Wed, 23 Dec 2020 06:40:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727063AbgLWGkX (ORCPT ); Wed, 23 Dec 2020 01:40:23 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:46687 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726069AbgLWGkW (ORCPT ); Wed, 23 Dec 2020 01:40:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608705534; 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=7+7+o89aTavHz0eQnsiLimPO6GFLiWT2IxDjqFbKFik=; b=OZCEAJaj/DbztF4JpnOJc3ukW9dafos95MZlpxMT+Z7MtTyni7llHrqLeC/1RXvzmppVsj xzSpLkVhA1832Ghoy9oM1M6VZqzRppOuqBtnRW3cJ9TXWOmRSmW5rS6tjrl7noJzFl2Pug XWK3rH6jZJgc4GpUnJgZllxgii/3ovM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-394-jyb7gkX5OXiv5Uo1kvek9A-1; Wed, 23 Dec 2020 01:38:51 -0500 X-MC-Unique: jyb7gkX5OXiv5Uo1kvek9A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1E3FB107ACF9; Wed, 23 Dec 2020 06:38:49 +0000 (UTC) Received: from [10.72.12.54] (ovpn-12-54.pek2.redhat.com [10.72.12.54]) by smtp.corp.redhat.com (Postfix) with ESMTP id D83575D9CC; Wed, 23 Dec 2020 06:38:36 +0000 (UTC) Subject: Re: [RFC v2 00/13] Introduce VDUSE - vDPA Device in Userspace To: Xie Yongji , mst@redhat.com, stefanha@redhat.com, sgarzare@redhat.com, parav@nvidia.com, akpm@linux-foundation.org, rdunlap@infradead.org, willy@infradead.org, viro@zeniv.linux.org.uk, axboe@kernel.dk, bcrl@kvack.org, corbet@lwn.net Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org References: <20201222145221.711-1-xieyongji@bytedance.com> From: Jason Wang Message-ID: Date: Wed, 23 Dec 2020 14:38:35 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201222145221.711-1-xieyongji@bytedance.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2020/12/22 下午10:52, Xie Yongji wrote: > This series introduces a framework, which can be used to implement > vDPA Devices in a userspace program. The work consist of two parts: > control path forwarding and data path offloading. > > In the control path, the VDUSE driver will make use of message > mechnism to forward the config operation from vdpa bus driver > to userspace. Userspace can use read()/write() to receive/reply > those control messages. > > In the data path, the core is mapping dma buffer into VDUSE > daemon's address space, which can be implemented in different ways > depending on the vdpa bus to which the vDPA device is attached. > > In virtio-vdpa case, we implements a MMU-based on-chip IOMMU driver with > bounce-buffering mechanism to achieve that. Rethink about the bounce buffer stuffs. I wonder instead of using kernel pages with mmap(), how about just use userspace pages like what vhost did? It means we need a worker to do bouncing but we don't need to care about annoying stuffs like page reclaiming? > And in vhost-vdpa case, the dma > buffer is reside in a userspace memory region which can be shared to the > VDUSE userspace processs via transferring the shmfd. > > The details and our user case is shown below: > > ------------------------ ------------------------- ---------------------------------------------- > | Container | | QEMU(VM) | | VDUSE daemon | > | --------- | | ------------------- | | ------------------------- ---------------- | > | |dev/vdx| | | |/dev/vhost-vdpa-x| | | | vDPA device emulation | | block driver | | > ------------+----------- -----------+------------ -------------+----------------------+--------- > | | | | > | | | | > ------------+---------------------------+----------------------------+----------------------+--------- > | | block device | | vhost device | | vduse driver | | TCP/IP | | > | -------+-------- --------+-------- -------+-------- -----+---- | > | | | | | | > | ----------+---------- ----------+----------- -------+------- | | > | | virtio-blk driver | | vhost-vdpa driver | | vdpa device | | | > | ----------+---------- ----------+----------- -------+------- | | > | | virtio bus | | | | > | --------+----+----------- | | | | > | | | | | | > | ----------+---------- | | | | > | | virtio-blk device | | | | | > | ----------+---------- | | | | > | | | | | | > | -----------+----------- | | | | > | | virtio-vdpa driver | | | | | > | -----------+----------- | | | | > | | | | vdpa bus | | > | -----------+----------------------+---------------------------+------------ | | > | ---+--- | > -----------------------------------------------------------------------------------------| NIC |------ > ---+--- > | > ---------+--------- > | Remote Storages | > ------------------- > > We make use of it to implement a block device connecting to > our distributed storage, which can be used both in containers and > VMs. Thus, we can have an unified technology stack in this two cases. > > To test it with null-blk: > > $ qemu-storage-daemon \ > --chardev socket,id=charmonitor,path=/tmp/qmp.sock,server,nowait \ > --monitor chardev=charmonitor \ > --blockdev driver=host_device,cache.direct=on,aio=native,filename=/dev/nullb0,node-name=disk0 \ > --export vduse-blk,id=test,node-name=disk0,writable=on,vduse-id=1,num-queues=16,queue-size=128 > > The qemu-storage-daemon can be found at https://github.com/bytedance/qemu/tree/vduse > > Future work: > - Improve performance (e.g. zero copy implementation in datapath) > - Config interrupt support > - Userspace library (find a way to reuse device emulation code in qemu/rust-vmm) > > This is now based on below series: > https://lore.kernel.org/netdev/20201112064005.349268-1-parav@nvidia.com/ > > V1 to V2: > - Add vhost-vdpa support I may miss something but I don't see any code to support that. E.g neither set_map nor dma_map/unmap is implemented in the config ops. Thanks > - Add some documents > - Based on the vdpa management tool > - Introduce a workqueue for irq injection > - Replace interval tree with array map to store the iova_map > > Xie Yongji (13): > mm: export zap_page_range() for driver use > eventfd: track eventfd_signal() recursion depth separately in different cases > eventfd: Increase the recursion depth of eventfd_signal() > vdpa: Remove the restriction that only supports virtio-net devices > vdpa: Pass the netlink attributes to ops.dev_add() > vduse: Introduce VDUSE - vDPA Device in Userspace > vduse: support get/set virtqueue state > vdpa: Introduce process_iotlb_msg() in vdpa_config_ops > vduse: Add support for processing vhost iotlb message > vduse: grab the module's references until there is no vduse device > vduse/iova_domain: Support reclaiming bounce pages > vduse: Add memory shrinker to reclaim bounce pages > vduse: Introduce a workqueue for irq injection > > Documentation/driver-api/vduse.rst | 91 ++ > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + > drivers/vdpa/Kconfig | 8 + > drivers/vdpa/Makefile | 1 + > drivers/vdpa/vdpa.c | 2 +- > drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 +- > drivers/vdpa/vdpa_user/Makefile | 5 + > drivers/vdpa/vdpa_user/eventfd.c | 229 ++++ > drivers/vdpa/vdpa_user/eventfd.h | 48 + > drivers/vdpa/vdpa_user/iova_domain.c | 517 ++++++++ > drivers/vdpa/vdpa_user/iova_domain.h | 103 ++ > drivers/vdpa/vdpa_user/vduse.h | 59 + > drivers/vdpa/vdpa_user/vduse_dev.c | 1373 ++++++++++++++++++++ > drivers/vhost/vdpa.c | 34 +- > fs/aio.c | 3 +- > fs/eventfd.c | 20 +- > include/linux/eventfd.h | 5 +- > include/linux/vdpa.h | 11 +- > include/uapi/linux/vdpa.h | 1 + > include/uapi/linux/vduse.h | 119 ++ > mm/memory.c | 1 + > 21 files changed, 2598 insertions(+), 36 deletions(-) > create mode 100644 Documentation/driver-api/vduse.rst > create mode 100644 drivers/vdpa/vdpa_user/Makefile > create mode 100644 drivers/vdpa/vdpa_user/eventfd.c > create mode 100644 drivers/vdpa/vdpa_user/eventfd.h > create mode 100644 drivers/vdpa/vdpa_user/iova_domain.c > create mode 100644 drivers/vdpa/vdpa_user/iova_domain.h > create mode 100644 drivers/vdpa/vdpa_user/vduse.h > create mode 100644 drivers/vdpa/vdpa_user/vduse_dev.c > create mode 100644 include/uapi/linux/vduse.h >