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 1CD05C64EC4 for ; Wed, 8 Mar 2023 11:55:03 +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 7521A2AC50 for ; Wed, 8 Mar 2023 11:55:02 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 6D410986701 for ; Wed, 8 Mar 2023 11:55:02 +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 5DA6E9866F2; Wed, 8 Mar 2023 11:55:02 +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 43EB59866EE for ; Wed, 8 Mar 2023 11:55:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: K28rg5dfPLG-02CxU92Pdw-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678276497; 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=L4hZo98+UXQ+0kYz5lbRPjykRGCYM7w+Ao/3kZ+T1SA=; b=f1krm7zhWXto/zYn5ckWj9w8IbJVUb6Ql7u0P+0rYUckoKQv9zRvRuQBjzqhkz8gsv /PnuUMKlEWXjtQKGBaLJgRfLOOJlQGw88S6C/b4eZnQcOXoxTQzSmWZ12eyMSuQeRDfT kWGjAea6COdCZ6X5g4gI6FJN53VhjBPJD8GkGi/Ny+S1YqRL40iCvUMV7DBHg2L2WuFs OYjM5pn4qsrvIMUBUcIh2tEIN1gQhzms4IBm32BKIe3ZuCyLExCsrQ6Jodew34oayxpk McaXAp1tkb/ltWQq8u6OBIyITRU/zT0EdaPxnRw78tIDDkp7boMZDdQQ6yhut2pn51Ki 1kQg== X-Gm-Message-State: AO0yUKX+oUQRmYEXXb8mBdksTC4xd1Wpu2OXr2yQ0EKaLTWM/Ggqudop wys18NI4J+LzebDutsv2AqG06AUxD6Lhryp4pAz5LDcsd0po4dog2qL542Q41hM2X1GKws5gxRp IPbx999MOzukTUUj/pithdNpIRfYw X-Received: by 2002:aa7:db53:0:b0:4ab:15d9:2dae with SMTP id n19-20020aa7db53000000b004ab15d92daemr17162598edt.14.1678276497713; Wed, 08 Mar 2023 03:54:57 -0800 (PST) X-Google-Smtp-Source: AK7set8oN2Nd8KCT+zigHcOBfKG3QAtMWTDA6m4JMvrqlpwVuX8hU7wKPNn2ynfvcHUGFs3Vn+JNaQ== X-Received: by 2002:aa7:db53:0:b0:4ab:15d9:2dae with SMTP id n19-20020aa7db53000000b004ab15d92daemr17162581edt.14.1678276497453; Wed, 08 Mar 2023 03:54:57 -0800 (PST) Date: Wed, 8 Mar 2023 06:54:52 -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: <20230308065109-mutt-send-email-mst@kernel.org> References: <80c4bc60c9119f68b66f5a003564cec719cc1487.1677761896.git.mst@redhat.com> 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: Re: [virtio-dev] [PATCH v10 08/10] admin: command list discovery On Mon, Mar 06, 2023 at 01:22:30PM +0100, Jiri Pirko wrote: > Thu, Mar 02, 2023 at 02:05:22PM CET, mst@redhat.com wrote: > >Add commands to find out which commands does each group support, > >as well as enable their use by driver. > >This will be especially useful once we have multiple group types. > > > >An alternative is per-type VQs. This is possible but will > >require more per-transport work. Discovery through the vq > >helps keep things contained. > > > >Signed-off-by: Max Gurtovoy > >Signed-off-by: Michael S. Tsirkin > > [...] > > > >+ > >+The driver issues the command VIRTIO_ADMIN_CMD_LIST_QUERY to > >+query the list of commands valid for this group and before sending > >+any commands for any member of a group. > >+ > >+The driver then enables use of some of the opcodes by sending to > >+the device the command VIRTIO_ADMIN_CMD_LIST_USE with a subset > >+of the list returned by VIRTIO_ADMIN_CMD_LIST_QUERY that is > >+both understood and used by the driver. > > To my untrained ear, this sounds somewhat similar to the feature > negotiantion mechanism. Why the fact that device/driver supports some > command can't be covered by just another feature? Looks like unnecassary > complexicity to negotiate supported commands like this. Absolutely, it is similar. The issue is that a single device can be an owner for multiple group types. For example, I think an SRIOV PF itself can have subfunctions with SIOV as well as virtual functions with SRIOV. And the set of supported commands might differ. We thus need a command that is kind of like features but per group type. As a small bonus as we are building this from scratch, I added something which was requested for a long time from features which is blocking access to commands not allowed by features. With standard virtio features we trust the driver not to send commands before enabling a feature and this was considered a maintainance/security problem. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org