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 ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (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 0E6EBEB64DC for ; Mon, 3 Jul 2023 04:29:40 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 3E9B316DD83 for ; Mon, 3 Jul 2023 04:29:40 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 274CF986533 for ; Mon, 3 Jul 2023 04:29:40 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 16327983FE8; Mon, 3 Jul 2023 04:29:40 +0000 (UTC) Mailing-List: contact virtio-comment-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 01EFB98644B for ; Mon, 3 Jul 2023 04:29:39 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-IronPort-AV: E=McAfee;i="6600,9927,10759"; a="393529989" X-IronPort-AV: E=Sophos;i="6.01,177,1684825200"; d="scan'208";a="393529989" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10759"; a="712430989" X-IronPort-AV: E=Sophos;i="6.01,177,1684825200"; d="scan'208";a="712430989" Message-ID: <2e176f24-293b-5be0-2928-e8ce0300e75a@intel.com> Date: Mon, 3 Jul 2023 12:29:32 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.12.0 Content-Language: en-US To: Parav Pandit , Xuan Zhuo Cc: "virtio-comment@lists.oasis-open.org" , "Michael S. Tsirkin" References: <1687243466.51691-1-xuanzhuo@linux.alibaba.com> <1688104464.531018-1-xuanzhuo@linux.alibaba.com> <1688111214.8488657-2-xuanzhuo@linux.alibaba.com> <1688111784.0426908-3-xuanzhuo@linux.alibaba.com> <7ab5978d-c503-c279-a42e-bcdbf40184d4@intel.com> <1688116457.7400494-4-xuanzhuo@linux.alibaba.com> <259c7b04-58df-8085-755f-a36993556a89@intel.com> From: "Zhu, Lingshan" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [virtio-comment] About the plan of Admin Queue On 6/30/2023 7:35 PM, Parav Pandit wrote: >> From: virtio-comment@lists.oasis-open.org > open.org> On Behalf Of Zhu, Lingshan >> Sent: Friday, June 30, 2023 6:33 AM >> > >>>>> Can we let the DPU notify the driver to create a new devicer from the >> backend? > Yes, why not. > >>>>> The key point is who want to create a new device. >>>> DPU can come with a certain number of pre-created ADIs, just make >>>> sure the orchestration SW is aware of their device IDs. >>>> > Cloud often need these devices to be created dynamically, many a time after the host OS is booted. > To be more generic, those devices to be created and connected to the host regardless of the life cycle of the host. > Xuan partly explained it. > >>>> If you want the DPU randomly create ADIs and notify the driver, I >>>> think we need interrupt, e.g., re-use config interrupt. But why DPU >>>> wants to create and hot plug in a device to a guest? >>>> Shall the host handle that or DPU pre-create then expose to baremteal >>>> machines? >>> In your scenario, the supervisor is on the os, which controls the DPU >>> to create new devices. >>> >>> In the cloud scenario, the vendor manager is in the DPU, and the >>> entire host is for users. Of course, there are situations where the >>> vendor manager are in the HOST. But for bare metal machines, the host >>> belongs to the customer, the vendor manager is only in the DPU. >>> >>> So when the customers buy a new nic for the host, the vendor manager >>> will plug a device to the host from the DPU. >> I understand once a customer orders a new NIC, you wants to present the NIC >> to the host. >> However you only owns the DPU and the customer owns the host, that means >> this creation and hot plug must be transparent to the host and there may not be >> a host driver help handling an interrupt/probe. >> > That is ok. when driver is loaded, it would query about its child devices and probe it, if we strictly want to follow SIOV model. > >> However this is not PCI which has a tree/switch and can enumerate devices to >> the host by spanning the device across the PCI hierarchy. >> > Those enumeration is triggered by the parent PCI device and pci bridge and switch will also discover it. > >> To address an ADI, there is only a device_id. >> > SIOV device must have a unique identifier at PCI bus level for sure. > I cannot speak more about it in this forum due to other logistics issue. > But assume that there is PCI level unique identifier for SIOV device that switches on the path will learn about. > >> So, do you mind share how your DPU offload the device model? What kind of >> device your DPU provide to the host? Lets see whether DPU can mediate this by >> its own? >> > It is a virtio nic, blk and other virtio devices for us. > A DPU hotplugs a device, host side either gets interrupt or later gets to know about it when explicitly queries. > There is no mediation per say here, it is just a dpu based SIOV device like a regular PF. > > For non virtio DPU device, I implemented them in Linux for dpus 2 years ago. > You might find a Linux reference model useful at [1]. > A usage model already exists in one OS and in use for non virtio devices. > This certainly works without SIOV unique PCI device identifiers, because DPU (non-host) managed SIOV device spec still does not exist. > > For virtio, I think we should wait for this piece to be defined and leverage that, instead of virtio tc creating its own. > > [1] https://github.com/Mellanox/scalablefunctions/wiki well I see SF facing the similar challenge, I can add a command for the driver to query all existing SIOV ADIs of a device, and the device return ADIs id and status. Looks good? and work for you @Xuan? Thanks This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/