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 DBDE3C4167B for ; Mon, 27 Nov 2023 11:28:17 +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 1D52E3E577 for ; Mon, 27 Nov 2023 11:28:17 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id DC5B89863D8 for ; Mon, 27 Nov 2023 11:28:16 +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 B5FF398638E; Mon, 27 Nov 2023 11:28:16 +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 A7E48986394 for ; Mon, 27 Nov 2023 11:28:16 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 5CNX0A9MNs6jZQKj2yaNlQ-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701084491; x=1701689291; 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=7ngxi6z1Lv9plKIMezJS8QgcaY2bgVa8MJURVLVx9e0=; b=nQMUKmArTtUowPBAiS55uGhSqVObkGHqw4xeyYQOUwj5aD8arG21jGK1hyRMYI/VhP rWla2y/T9RXmJNOADx6AiMw7CwwojbTl4wL/gahpMQr3LDpVSuyAAWT2M9wzUJuNumcJ yWgPXn+bifLoeNh8cMeHWBteE16ZB8KFM2/7xmStMvv6i0yq0k8cnBqXbzX3QvKjx25q +49oLf/BR7ZB+JobCnS97iKZE4WNXZYfkntp5MSmH+m8LjvviAGeG2T2UvhVwICpDpi8 hoPxtFULpAz82SkSjTg4UWzNIunK8Yo1TwUyeJOYK4lGAJogPQNlSgjOLcGkfmGUqHVd VEQg== X-Gm-Message-State: AOJu0YwCs6VJrYcs55jfdzJg6qT1aR8o8UTESH8E3fcib0eU+5HkcsGy AdyM+g7C9WtdDJgjAtb2nvcSkbQs26nOMUARsDPGSFdb7ZGRZJ9qqE0L0dAm4MwLKmTVcIa3/Ok 0AJ+PWaNIJ0yj9mCeJSh0Kt+gZoRc843rPQ== X-Received: by 2002:a17:906:6811:b0:a02:f424:f817 with SMTP id k17-20020a170906681100b00a02f424f817mr7568663ejr.30.1701084491036; Mon, 27 Nov 2023 03:28:11 -0800 (PST) X-Google-Smtp-Source: AGHT+IFWLWhNC50m4xnNEy4eWXqafqhI/CnUbq0aGEkzmwFLYfQb8VoH4t9i8deHOaYi0xTOz6S2OA== X-Received: by 2002:a17:906:6811:b0:a02:f424:f817 with SMTP id k17-20020a170906681100b00a02f424f817mr7568649ejr.30.1701084490743; Mon, 27 Nov 2023 03:28:10 -0800 (PST) Date: Mon, 27 Nov 2023 06:28:06 -0500 From: "Michael S. Tsirkin" To: Parav Pandit Cc: Jason Wang , "virtio-comment@lists.oasis-open.org" , "cohuck@redhat.com" , "sburla@marvell.com" , Shahaf Shuler , "si-wei.liu@oracle.com" , "xuanzhuo@linux.alibaba.com" , Heng Qi Message-ID: <20231127062256-mutt-send-email-mst@kernel.org> References: <20231122094431-mutt-send-email-mst@kernel.org> <20231124002357-mutt-send-email-mst@kernel.org> <20231124011125-mutt-send-email-mst@kernel.org> <20231124062907-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: Re: [virtio-comment] Re: [PATCH v6 2/5] virtio-net: Add flow filter capabilities read commands On Mon, Nov 27, 2023 at 10:19:49AM +0000, Parav Pandit wrote: > > > From: Michael S. Tsirkin > > Sent: Friday, November 24, 2023 5:04 PM > > > > On Fri, Nov 24, 2023 at 06:31:03AM +0000, Parav Pandit wrote: > > > > > > > From: Michael S. Tsirkin > > > > Sent: Friday, November 24, 2023 11:48 AM > > > > > > > > On Fri, Nov 24, 2023 at 05:40:26AM +0000, Parav Pandit wrote: > > > > > > we > > > > > > strongly suggest that *drivers* support both old and new > > > > > > mechanism, and then *devices* will only implement what's required. > > > > > There are other examples in the same document that makes things > > > > > worst > > > > with old and new. > > > > > > > > > > Also there is literally no way to enforce that driver supports > > > > > both and new. It is just sounds like an excuse to force infinite > > > > > config space. > > > > > > > > There is a very simple method though. We allow devices to expose a > > > > subset of features when DMA is not used. So drivers that want > > > > maximum features will always opt for DMA. We can also strongly > > > > recommend that all drivers support DMA if available. > > > Yeah, don't see how this is elegant at all with all mixed bits. > > > > It's elegant because simple low end devices can cheaply implement MMIO and > > not worry about DMA. > > > It is not of much help in this case because any low end cheap device which want to support flow filter commands need to have CVQ anyway. > And hence reusing the same CVQ is more elegant that already does the DMA. > > So CVQ is fulfilling all the below needs. > 1. Single interface for the get/set config flow filters > 2. DMA the data > 3. Not have any partial issues I don't know what these are. > 4. provides consistent structures that provisioning side will be able to use Problem for provisioning is extra definitions will be needed, in a device specific way. > > > Nor do I see any enforcement, single method via cvq still holds strong. > > > > You don't need to enforce things, if people want to put a lot of RAM on device > > and put it in a register let them. > > > Not enforced. It uses the CVQ for flow group and flow filter life cycles and for the sharing this config as well. > Also aligns with stats that rest also agreed on. I am talking about your attempt to generally say "no more config fields everything must be in CVQ". I think it's wrong definitiely for non network devices must sometimes for network too and generally we need a solution for config over DMA. This specific thing - whether it fits in CVQ is a separate discussion. > > > > > > > > > > > > > > > > > > > > The method proposed here is elegant and clearly promote one way to > > > > > do > > > > things for driver and device with predictability. > > > > > > > > > > > > > I don't see it as elegant at all. What is elegant is *a single tag* > > > > that describes each property of the device. And this single tag should be > > good for everything: > > > > driver, provisioning, migration. And config space offset serves as such. > > > The single tag is the set of structures. > > > > I have no idea how this will work. If migration format i started reviewing is > > anything to go by then there will be a huge elaborate structure nothing single > > or simple. By comparison there's already a proposal how provisioning can > > work by supplying config space. > > it is just a clean model to grasp. > > > The provisioning model is simple is to supply all the configuration. > To draw parallels to some sw side, > > There is per functionality socket option to set things, instead of one giant structure. > There is per functionality ethtool option/cmd instead of Set ALL/get ALL enforcement. I'm not sure how much of a parallel one can draw. Do not see a lot of similarity. Devices commonly use register map. Everyone understands this paradigm. I am not altogether happy with the way you are making migration generate duplicate definitions for lots of things we already have definitions for. Having a 3rd one for provisioning? Gimme a break. > > > Provisioning access them via owner device. > > > Member driver access them via CVQ or 1.2 legacy config space. > > 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/