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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 796E6C4332F for ; Sun, 6 Nov 2022 13:13:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1orfRc-0002RQ-4C; Sun, 06 Nov 2022 08:12:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1orfRX-0002RA-KW for qemu-devel@nongnu.org; Sun, 06 Nov 2022 08:12:07 -0500 Received: from szxga08-in.huawei.com ([45.249.212.255]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1orfRS-0004qo-1U for qemu-devel@nongnu.org; Sun, 06 Nov 2022 08:12:07 -0500 Received: from kwepemi100025.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4N4vrj6gkcz15MJF; Sun, 6 Nov 2022 21:11:33 +0800 (CST) Received: from [10.174.148.223] (10.174.148.223) by kwepemi100025.china.huawei.com (7.221.188.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sun, 6 Nov 2022 21:11:40 +0800 Message-ID: <2b3d77fc-ece4-32b4-964a-c939613f1ca3@huawei.com> Date: Sun, 6 Nov 2022 21:11:39 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v7 resend 0/4] add generic vDPA device support To: "Michael S. Tsirkin" CC: , , , , , , , , , References: <20221105083629.1058-1-longpeng2@huawei.com> <20221105103601-mutt-send-email-mst@kernel.org> <5387e1e7-b741-b6a1-f091-f15d5f136e38@huawei.com> <20221106011943-mutt-send-email-mst@kernel.org> In-Reply-To: <20221106011943-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.148.223] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi100025.china.huawei.com (7.221.188.158) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.255; envelope-from=longpeng2@huawei.com; helo=szxga08-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Qemu-devel" Reply-to: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" From: longpeng2--- via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 在 2022/11/6 13:22, Michael S. Tsirkin 写道: > On Sun, Nov 06, 2022 at 08:17:07AM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote: >> >> >> 在 2022/11/6 0:43, Michael S. Tsirkin 写道: >>> On Sat, Nov 05, 2022 at 04:36:25PM +0800, Longpeng(Mike) wrote: >>>> From: Longpeng >>>> >>>> Hi guys, >>>> >>>> With the generic vDPA device, QEMU won't need to touch the device >>>> types any more, such like vfio. >>> >>> With this kind of passthrough migration is completely MIA right? >>> Better add a blocker... >> >> Oh, I missed the "vdpa-dev: mark the device as unmigratable" since v4 and >> I'll add it in the next version. >> >> We'll support passthrough migration in the next step. We have already >> written a demo that can migrate between some offloading cards. > > Hmm ok. Backend disconnect can't work though, can it? State > is by necessity lost when backend crashes. >Yes, it can't. >>> And given this is there an advantage over VFIO? >> >> I think the answer is the same as "why we need vDPA" if we compare it with >> VFIO. > > The answer is mostly because you can migrate and support backend > disconnect, no? > Migrating between different hardware is the first consideration in our requirement, supporting backend disconnect is a low priority. >>> >>>> We can use the generic vDPA device as follow: >>>> -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-X >>>> Or >>>> -M microvm -m 512m -smp 2 -kernel ... -initrd ... -device \ >>>> vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-x >>> >>>> Changes v6 -> v7: >>>> (v6: https://mail.gnu.org/archive/html/qemu-devel/2022-05/msg02821.html) >>>> - rebase. [Jason] >>>> - add documentation . [Stefan] >>>> >>>> Changes v5 -> v6: >>>> Patch 2: >>>> - Turn to the original approach in the RFC to initialize the >>>> virtio_pci_id_info array. [Michael] >>>> https://lore.kernel.org/all/20220105005900.860-2-longpeng2@huawei.com/ >>>> Patch 3: >>>> - Fix logical error of exception handler around the post_init. >>>> [Stefano] >>>> - Fix some coding style warnings. [Stefano] >>>> Patch 4: >>>> - Fix some coding style warnings. [Stefano] >>>> >>>> Changes v4 -> v5: >>>> Patch 3: >>>> - remove vhostfd [Jason] >>>> - support virtio-mmio [Jason] >>>> >>>> Changes v3 -> v4: >>>> v3: https://www.mail-archive.com/qemu-devel@nongnu.org/msg877015.html >>>> - reorganize the series [Stefano] >>>> - fix some typos [Stefano] >>>> - fix logical error in vhost_vdpa_device_realize [Stefano] >>>> >>>> Changes v2 -> v3 >>>> Patch 4 & 5: >>>> - only call vdpa ioctls in vdpa-dev.c [Stefano, Longpeng] >>>> - s/VQS_NUM/VQS_COUNT [Stefano] >>>> - check both vdpa_dev_fd and vdpa_dev [Stefano] >>>> Patch 6: >>>> - move all steps into vhost_vdpa_device_unrealize. [Stefano] >>>> >>>> Changes RFC -> v2 >>>> Patch 1: >>>> - rename 'pdev_id' to 'trans_devid' [Michael] >>>> - only use transitional device id for the devices >>>> listed in the spec [Michael] >>>> - use macros to make the id_info table clearer [Longpeng] >>>> - add some modern devices in the id_info table [Longpeng] >>>> Patch 2: >>>> - remove the GET_VECTORS_NUM command [Jason] >>>> Patch 4: >>>> - expose vdpa_dev_fd as a QOM preperty [Stefan] >>>> - introduce vhost_vdpa_device_get_u32 as a common >>>> function to make the code clearer [Stefan] >>>> - fix the misleading description of 'dc->desc' [Stefano] >>>> Patch 5: >>>> - check returned number of virtqueues [Stefan] >>>> Patch 6: >>>> - init s->num_queues [Stefano] >>>> - free s->dev.vqs [Stefano] >>>> >>>> >>>> Longpeng (Mike) (4): >>>> virtio: get class_id and pci device id by the virtio id >>>> vdpa: add vdpa-dev support >>>> vdpa: add vdpa-dev-pci support >>>> docs: Add generic vhost-vdpa device documentation >>>> >>>> docs/system/devices/vhost-vdpa-device.rst | 43 +++ >>>> hw/virtio/Kconfig | 5 + >>>> hw/virtio/meson.build | 2 + >>>> hw/virtio/vdpa-dev-pci.c | 102 ++++++ >>>> hw/virtio/vdpa-dev.c | 377 ++++++++++++++++++++++ >>>> hw/virtio/virtio-pci.c | 88 +++++ >>>> include/hw/virtio/vdpa-dev.h | 43 +++ >>>> include/hw/virtio/virtio-pci.h | 5 + >>>> 8 files changed, 665 insertions(+) >>>> create mode 100644 docs/system/devices/vhost-vdpa-device.rst >>>> create mode 100644 hw/virtio/vdpa-dev-pci.c >>>> create mode 100644 hw/virtio/vdpa-dev.c >>>> create mode 100644 include/hw/virtio/vdpa-dev.h >>>> >>>> -- >>>> 2.23.0 >>> >>> . > > > .