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 7E2EFC4332F for ; Tue, 13 Dec 2022 15:38:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p57Lz-0000tn-Ur; Tue, 13 Dec 2022 10:38:00 -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 1p57Lw-0000tW-Us for qemu-devel@nongnu.org; Tue, 13 Dec 2022 10:37:56 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p57Lt-0002K8-Mh for qemu-devel@nongnu.org; Tue, 13 Dec 2022 10:37:56 -0500 Received: from kwepemi100025.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NWjK43QsZzlVhw; Tue, 13 Dec 2022 23:36:40 +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 15.1.2375.34; Tue, 13 Dec 2022 23:37:37 +0800 Message-ID: Date: Tue, 13 Dec 2022 23:37:35 +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 v10 5/5] docs: Add generic vhost-vdpa device documentation To: Stefano Garzarella CC: , , , , , , , , References: <20221205084943.2259-1-longpeng2@huawei.com> <20221205084943.2259-6-longpeng2@huawei.com> <20221213143511.awu6ibpavokxrghv@sgarzare-redhat> In-Reply-To: <20221213143511.awu6ibpavokxrghv@sgarzare-redhat> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.148.223] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi100025.china.huawei.com (7.221.188.158) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.187; envelope-from=longpeng2@huawei.com; helo=szxga01-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: , Reply-to: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" From: longpeng2--- via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 在 2022/12/13 22:35, Stefano Garzarella 写道: > On Mon, Dec 05, 2022 at 04:49:43PM +0800, Longpeng(Mike) wrote: >> From: Longpeng >> >> Signed-off-by: Longpeng >> --- >> .../devices/vhost-vdpa-generic-device.rst     | 66 +++++++++++++++++++ >> 1 file changed, 66 insertions(+) >> create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst >> >> diff --git a/docs/system/devices/vhost-vdpa-generic-device.rst >> b/docs/system/devices/vhost-vdpa-generic-device.rst >> new file mode 100644 >> index 0000000000..7d13359ea1 >> --- /dev/null >> +++ b/docs/system/devices/vhost-vdpa-generic-device.rst >> @@ -0,0 +1,66 @@ >> + >> +========================= >> +vhost-vDPA generic device >> +========================= >> + >> +This document explains the usage of the vhost-vDPA generic device. >> + >> +Description >> +----------- >> + >> +vDPA(virtio data path acceleration) device is a device that uses a >> datapath >> +which complies with the virtio specifications with vendor specific >> control >> +path. >> + >> +QEMU provides two types of vhost-vDPA devices to enable the vDPA >> device, one >> +is type sensitive which means QEMU needs to know the actual device type >> +(e.g. net, blk, scsi) and another is called "vhost-vDPA generic >> device" which >> +is type insensitive. >> + >> +The vhost-vDPA generic device builds on the vhost-vdpa subsystem and >> virtio >> +subsystem. It is quite small, but it can support any type of virtio >> device. >> + > > Maybe we can also add a minimum requirement section (e.g. we needs at > least Linux v5.18 for VHOST_VDPA_GET_VQS_COUNT) > Ok. >> +Examples >> +-------- >> + >> +1. Please make sure the modules listed bellow are installed: >> +    vhost.ko >> +    vhost_iotlb.ko >> +    vdpa.ko >> +    vhost_vdpa.ko >> + >> + >> +2. Prepare the vhost-vDPA backends, here is an example using >> vdpa_sim_blk >> +   device: >> + >> +:: > > Should we add also a `modprobe vhost-vdpa` step? > This is already described in Step 1. >> +  host# modprobe vdpa_sim_blk >> +  host# vdpa dev add mgmtdev vdpasim_blk name blk0 >> +  (...you can see the vhost-vDPA device under /dev directory now...) >> +  host# ls -l /dev/vhost-vdpa-* >> +  crw------- 1 root root 236, 0 Nov  2 00:49 /dev/vhost-vdpa-0 >> + >> +Note: >> +It needs some vendor-specific steps to provision the vDPA device if >> you're >> +using real HW devices, such as installing the vendor-specific vDPA >> driver >> +and binding the device to the driver. >> + >> + >> +3. Start the virtual machine: >> + >> +Start QEMU with virtio-mmio bus: >> + >> +:: >> +  host# qemu-system                                                  \ >> +      -M microvm -m 512 -smp 2 -kernel ... -initrd ...               \ >> +      -device vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-0           \ >> +      ... >> + >> + >> +Start QEMU with virtio-pci bus: >> + >> +:: >> +  host# qemu-system                                                  \ >> +      -M pc -m 512 -smp 2                                            \ >> +      -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-0       \ >> +      ... >> -- >> 2.23.0 >> > > .