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 4AB4AEB64DD for ; Mon, 3 Jul 2023 08:01:44 +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 610F56008D for ; Mon, 3 Jul 2023 08:01:43 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 3FBCD98655E for ; Mon, 3 Jul 2023 08:01:43 +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 2822998644B; Mon, 3 Jul 2023 08:01:43 +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 13B6F98644C for ; Mon, 3 Jul 2023 08:01:43 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-IronPort-AV: E=McAfee;i="6600,9927,10759"; a="347605193" X-IronPort-AV: E=Sophos;i="6.01,177,1684825200"; d="scan'208";a="347605193" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10759"; a="831725291" X-IronPort-AV: E=Sophos;i="6.01,177,1684825200"; d="scan'208";a="831725291" Message-ID: <08ead575-d3d3-0c3f-9cec-8a604bdb5014@intel.com> Date: Mon, 3 Jul 2023 16:01:35 +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: Xuan Zhuo Cc: "virtio-comment@lists.oasis-open.org" , "Michael S. Tsirkin" , Parav Pandit 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> <2e176f24-293b-5be0-2928-e8ce0300e75a@intel.com> <1688363658.0517473-7-xuanzhuo@linux.alibaba.com> From: "Zhu, Lingshan" In-Reply-To: <1688363658.0517473-7-xuanzhuo@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [virtio-comment] About the plan of Admin Queue On 7/3/2023 1:54 PM, Xuan Zhuo wrote: > On Mon, 3 Jul 2023 12:29:32 +0800, "Zhu, Lingshan" wrote: >> >> 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? > Can the device notifies the driver by a interrupt? Of course this can be an option as previously discussed. That would be a config interrupt(with proper suppression) from the management device, which requires a new cap in a bar, then you still need to fetch the information. A proposal: a new cap, at least contains: total number of the ADIs. Then once any ADIs are created or removed, the PF driver get a notification. Works for you? > > Thanks. > > >> 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/ > 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/