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 37805CDB465 for ; Thu, 19 Oct 2023 11:20:37 +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 79C7642D6D for ; Thu, 19 Oct 2023 11:20:36 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 5D6E09868E9 for ; Thu, 19 Oct 2023 11:20:36 +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 528949868DE; Thu, 19 Oct 2023 11:20:36 +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 84E6A9868DF for ; Thu, 19 Oct 2023 11:19:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 8yAHaCWaNn-19FJ8Eq13CQ-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697714377; x=1698319177; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=KPPkzkyOHe8lgJCE2K+OBlRiqiWjtc6mjWikPe/q1N4=; b=NpP1GUXT3q+vFGKm9paE8q+gXz89jK5dzCzapjUUsoffvF0oz8elNX8mAQ6XqlbkWU JFeQDDhGthoPy7vnbBT8iwWBpvp3wyXe1HbcH/Yj2ml7YGOqEtKAOFU9xC8026L0nq8X UQ0GzpvYesQF2ljTXDcAnHRVGJScAvGynPV4XISBXgumnc7giwA6PziKEMxY+opY7fqn Nn9HUb3bzuJ4gY9td/0IG+DgIuod8IPytm+NC5av+Gc26fRaBawG1cR6sFq6oTS5vi4/ tEMXeq6CETlinDE4/D9FTZzukquHESskoDv4s+/9lXvLT2Q4q4avBLxjyGTStFHx6IGx v9Mw== X-Gm-Message-State: AOJu0Yx+E/aUoT+KgFdzgyGPDEx0kA8fz10fUj0bJM9Y0SXKZ+CZEPSE 02l2Mxk+6pS/GWJHSpheuoRyygaJgP5jUKJ3meVUgPHr7Pl7fxPL0KxgwAM3huMM0s6Y8UKAGbw FKLcAMfg+g0W8EKXyLnEiNyYpWjrnAakaog== X-Received: by 2002:a5d:6948:0:b0:32d:9e72:659d with SMTP id r8-20020a5d6948000000b0032d9e72659dmr1219873wrw.63.1697714377285; Thu, 19 Oct 2023 04:19:37 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGxHqgFQ3yR/uFYarIZYPMYyjVUKZt7S5rBJLzhMnHQOpve49N7YH+SPsPtjD+U6hReDuZp/g== X-Received: by 2002:a5d:6948:0:b0:32d:9e72:659d with SMTP id r8-20020a5d6948000000b0032d9e72659dmr1219861wrw.63.1697714376934; Thu, 19 Oct 2023 04:19:36 -0700 (PDT) Date: Thu, 19 Oct 2023 07:19:31 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: "Zhu, Lingshan" , Jason Wang , "virtio-comment@lists.oasis-open.org" , "cohuck@redhat.com" , "sburla@marvell.com" , Shahaf Shuler , Maor Gottlieb , Yishai Hadas Message-ID: <20231019070411-mutt-send-email-mst@kernel.org> References: <860e52ef-8cfc-408a-b3cc-2551ef6118d1@intel.com> <7bc82c01-19ad-4180-914b-9304e10ef7c3@intel.com> <20231019051406-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Subject: Re: [virtio-comment] Re: [PATCH v1 3/8] device-context: Define the device context fields for device migration On Thu, Oct 19, 2023 at 10:33:15AM +0000, Parav Pandit wrote: > > From: Zhu, Lingshan > > Sent: Thursday, October 19, 2023 2:48 PM > > > > On 10/19/2023 5:14 PM, Michael S. Tsirkin wrote: > > > On Thu, Oct 19, 2023 at 09:13:16AM +0000, Parav Pandit wrote: > > >>> Oh, really? Quite interesting, do you want to move all config space > > >>> fields in VF to admin vq? Have a plan? > > >> Not in my plan for spec 1.4 time frame. > > >> I do not want to divert the discussion, would like to focus on device > > migration phases. > > >> Lets please discuss in some other dedicated thread. > > > Possibly, if there's a way to send admin commands to vf itself then > > > Lingshan will be happy? > > still need to prove why admin commands are better than registers. > > Virtio spec development is not proof based approach. Please stop asking for it. > > I tried my best to have technical answer in [1]. > I explained that registers simply do not work for passthrough mode > (if this is what you are asking when you are asking prove its better). > They can work for non_passthrough mediated mode. > > A member device may do admin commands using registers. Michael and I are discussing presently in the same thread. > > Since there are multiple things to be done for device migration, dedicated register set for each functionality do not scale well, hard to maintain and extend. > A register holding a command content make sense. > > Now, with that, if this can be useful only for non_passthrough, I made humble request to transport them using AQ, this way, you get all benefits of AQ. > And trying to understand, why AQ cannot possible or inferior? I think the real limitation is with the SRIOV group type. If using PASID instead of source id for isolation then we'd need a new group type. And maybe a simpler interface than virtqueue since it's all slow path anyway. > If you have commands like suspend/resume device, register or queue transport simply don’t work, because it's wrong to bifurcate the device with such weird API. > If you want to biferacate for mediation software, it probably makes sense to operate at each VQ level, config space level. Such are very different commands than passthrough. > I think vdpa has demonstrated that very well on how to do specific work for specific device type. So some of those work can be done using AQ. > > [1] https://lore.kernel.org/virtio-comment/870ace02-f99c-4582-932f-bd103362dae9@intel.com/T/#m37743aa924536d0256d6b3b8e83a11c750f28794 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. 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