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 843C8C64EC4 for ; Wed, 8 Mar 2023 11:50:59 +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 D72152B062 for ; Wed, 8 Mar 2023 11:50:58 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id CFCE09866F9 for ; Wed, 8 Mar 2023 11:50:58 +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 C43A29866EF; Wed, 8 Mar 2023 11:50:58 +0000 (UTC) Mailing-List: contact virtio-dev-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 9AA249866FD for ; Wed, 8 Mar 2023 11:50:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: OY56LbZNNwqt6HN9lmeYww-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678276253; h=in-reply-to: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=T2GPFjrQ1CfMCyHjnQX20+BKx03PRS9ZfqJ0o9AZ380=; b=k2ArGDHJ8VOaOigE3qQ2eOST2dOMp+VV/PnFoMu9vdCbZL6CmrSjDL2+0RitW7NF9M K+aeVFoZD5gSpeKOIGX2RrHTWKkDiqc3LD1kss/rFsab9+Htjl5A6DlMQkGfIehrO0H+ g5vusPD+fg4NBHdgqAIbgquwhlmAmryHdumkr9rmGK6KyfAbXkJI4yOQseSMhRS0Yy6u XYtC1dUV0JBInsA+6tZ0yuBPtpYINiHmuEQmZQbdzfJLHiApSWV4n1IjPHw4xDvQCRrX VF/as6hkigFcQzVmwqsRh3BKyxNjA33dMzcBYsG5SJ8hnMvWTXL+c+Ik7Bzqke0LFPdU KEXA== X-Gm-Message-State: AO0yUKVQBIMML0tL0XNHSG+VjWW2D/nbaN+AVM/3fc2EyQMsN6xY9v8L G0ngcW9RXJRmVQm6/7pAlOo+GHetyrfAVHtRdOYBqJoiqsQATEX5eCMjsvtzx/YgnC5ANm/kR9P Ezc5zYzMYDfWjgT4ddmhlqecR0spv X-Received: by 2002:a5d:4445:0:b0:2c3:f79a:7319 with SMTP id x5-20020a5d4445000000b002c3f79a7319mr12284337wrr.17.1678276253247; Wed, 08 Mar 2023 03:50:53 -0800 (PST) X-Google-Smtp-Source: AK7set8hhLeg+wcJMmnmv2Aei9HH4jb7ofAViUm3Hd8uL1mAcJpvSpcw+Lk2csIG531yTQRDRvi3kw== X-Received: by 2002:a5d:4445:0:b0:2c3:f79a:7319 with SMTP id x5-20020a5d4445000000b002c3f79a7319mr12284323wrr.17.1678276252921; Wed, 08 Mar 2023 03:50:52 -0800 (PST) Date: Wed, 8 Mar 2023 06:50:48 -0500 From: "Michael S. Tsirkin" To: Jiri Pirko Cc: virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org, jasowang@redhat.com, cohuck@redhat.com, sgarzare@redhat.com, stefanha@redhat.com, nrupal.jani@intel.com, Piotr.Uminski@intel.com, hang.yuan@intel.com, virtio@lists.oasis-open.org, Zhu Lingshan , pasic@linux.ibm.com, Shahaf Shuler , Parav Pandit , Max Gurtovoy Message-ID: <20230308064505-mutt-send-email-mst@kernel.org> References: <20c81b66f0b21b5bd646c24840ac3f8462c86acf.1677761896.git.mst@redhat.com> <20230306133816-mutt-send-email-mst@kernel.org> <20230307111458-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=us-ascii Content-Disposition: inline Subject: [virtio-dev] Re: [virtio-comment] Re: [virtio] [PATCH v10 04/10] admin: introduce virtio admin virtqueues On Wed, Mar 08, 2023 at 11:05:00AM +0100, Jiri Pirko wrote: > Tue, Mar 07, 2023 at 05:30:18PM CET, mst@redhat.com wrote: > >On Tue, Mar 07, 2023 at 08:36:41AM +0100, Jiri Pirko wrote: > >> Hmm, if not for now, the future exension would not be so simple, I fear. > > > >Without knowing what it is I can't say. > > Yep, so basically you say, for other things if they appear, > let's introduce another queue type? If yes, sounds fair to me. Yes. For example I find it likely that live migration/failover support will require a queue where driver pre-adds buffers and then device supplies information as state changes. > > > > >> > >> > > >> >Passing commands to devices themselves is already covered in spec > >> >reasonably well though not in a generic way. > >> > >> You mean using the control queue, correct? > > > >Depends on the device type. network devices have a control queue, yes. > > > >> >From one of the patch description of this patchset I understand that you > >> cannot use control queue for this because control queue is > >> device-specific, yet group control is device-agnostic. > >> > >> My undestanding therefore was, that the admin queue you are introducing > >> serves as a generic carrier for device-agnostic commands, in parallel > >> for having control queue serving as a generic carrier of device-specific > >> commands. If this is not the case, I think it would be nice to describe > >> the exact monivation and scope of admin queue. > > > >Nope unfortunately. This queue is just a carrier for admin commands. > >admin commands are commands that talk to one device about other > >devices. There's clearly no mechanism in the spec to do that, > >so we plug this hole. > > Okay, in that case "admin" sounds a bit misleading as for me it > implicates that this is for "administration" of the device. Yet is is > for the administration of other devices (slaves). > > Perhaps there could be different term used to clarify? > Group leader virtqueue? > Group owner virtqueue? > Group master virtqueue? I used group administration virtqueue in a couple of places, just inconsistently. Good enough? > > > > > > > >> > >> > > >> >What we lack is passing commands about one device to another device. > >> >E.g. control VFs through PFs. > >> > >> Could you provide examples of such commands please? > > > >For example a common feature is to program a vlan and have device > >put a given VF inside this vlan. > > I don't follow entirely. The way how the VF is connected to network > should be ouf of the scope of this interface. The eswitch manager should > take care. What you say sounds awfully like the "ip vf" legacy > interface, which should not be considered here I believe. > > If PF would be the eswitch manager, there are other means to do network > programming, using eswitch port representors. But I don't think this is > the can of worms we want to open now. I don't think we have a usecase > for it currently. Am I wrong Parav? > > > > > > >In a virtualization scenario host controls this vlan programming giving > >the network a measure of protection from VFs. If a VF is passed through > >to a VM, IOMMU limits VFs to only access guest memory so host has to do > >this programming through a PF. > > Understood. This really looks like "ip vf" legacy. I strongly believe > it should not be supported. > > Any other commands you have in mind? > > > > > > > > > >> > >> >This is what groups do. > >> >But if we see more uses we can always add them. > >> > > >> > > >> >I'd rather avoid being too generic though. > >> > >> In that case, why not to avoid using generic terms and stay > >> "group-centric"? What I mean is: > >> "Administration Virtqueues" -> "Group Administration Virtqueues" > >> "struct virtio_admin_cmd" -> "struct virtio_group_admin_cmd" > >> > >> Etc. Helps to avoid confusion. > > > >Sure, I tried to do that but missed some opportunities. > >Will address. > > Cool. > > > > > >> > >> > > >> > > >> > > >> > > >> >> > >> >> >+than one administration virtqueue. > >> > >> > >> [...] > >> > > > > > >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/ > > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org