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 91693C07CB1 for ; Mon, 27 Nov 2023 13:15:00 +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 0B1386846D for ; Mon, 27 Nov 2023 13:15:00 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id F2C009863BE for ; Mon, 27 Nov 2023 13:14:59 +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 E83C298639C; Mon, 27 Nov 2023 13:14:59 +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 DB2EF9863A1 for ; Mon, 27 Nov 2023 13:14:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: ROaz2thIN4Kxjm7IXO-vWA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701090896; x=1701695696; 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=ucLx9TMIAKRE9xGOwyG0JHIcs24usxbv0cB+EtnOjGo=; b=WP1qgHMKTuy9iFvY5Ajeah3gbs7WXWzRtHl8EkvGsyBcvxlzMT2AJSj+uc72/7WsFC yIBrw8XiCuc6+2ScbS6KlbBYrEI4060l8APSyJPd2tlDNxWnBXkOqdUWDeP6G9B+bR1s XCCkID1L+xl5WYjLs7RpXsYMr5mBRH4vzf7EwZUapuX5SCBVMHQ0WAP1/s7pNkUtCmgY cMVTWNqg+fOOOEsm8NaVmJRXQvMw7OVdKxdvHc9c/OzfsW2lDomwv+7TCoPiTbCXjb1x ATHDPR9FGSZUSCtMDXBUexm29zqlj/0gNKFECFIC9y8i96TYdd8zg73I7LDsy3G8RsOQ ZCNQ== X-Gm-Message-State: AOJu0Ywv2Net72W1H2cUps5IXW9ixRyaZyLidKL5FJ626fBgwPkO0gjs THoZy1D532y5AoNLss0Yv9Jo9aa4fZ/M9VR8NG4Qkwwt/aOcHY1aqLA4C2iJdLN6XYvjuc/qmEM b4DmVXczJl7+dmSjryDLutukZfMn/n7KcFg== X-Received: by 2002:a05:600c:4f42:b0:40a:28b1:70f8 with SMTP id m2-20020a05600c4f4200b0040a28b170f8mr9142020wmq.21.1701090896442; Mon, 27 Nov 2023 05:14:56 -0800 (PST) X-Google-Smtp-Source: AGHT+IHmsUwHcO6bn5rlQiUUmQisi80sQZEitoO3+Ql0cog+NhV1oTSPhXHohrIKrzwZEFTfBVVz3w== X-Received: by 2002:a05:600c:4f42:b0:40a:28b1:70f8 with SMTP id m2-20020a05600c4f4200b0040a28b170f8mr9141989wmq.21.1701090896000; Mon, 27 Nov 2023 05:14:56 -0800 (PST) Date: Mon, 27 Nov 2023 08:14:52 -0500 From: "Michael S. Tsirkin" To: Cornelia Huck Cc: Parav Pandit , Jason Wang , "virtio-comment@lists.oasis-open.org" , "sburla@marvell.com" , Shahaf Shuler , "si-wei.liu@oracle.com" , "xuanzhuo@linux.alibaba.com" , Heng Qi Message-ID: <20231127081255-mutt-send-email-mst@kernel.org> References: <20231124011125-mutt-send-email-mst@kernel.org> <20231124062907-mutt-send-email-mst@kernel.org> <20231127062256-mutt-send-email-mst@kernel.org> <20231127064138-mutt-send-email-mst@kernel.org> <87leajxs4s.fsf@redhat.com> MIME-Version: 1.0 In-Reply-To: <87leajxs4s.fsf@redhat.com> 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 02:06:27PM +0100, Cornelia Huck wrote: > >> > > > 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. > >> > In vdpa tool and other OS tools of iproute2 developed, setting and getting > >> those device specific values are useful. > >> > It is ok. > >> > >> It does not become ok just by saying so. You are taking a single RO value and > >> instead of it having an address there are now 2 other ways to address it. And > >> you fail to see the problem and the pain you are inflicting on software > >> developers. Just stick with an address if you can. > > There is zero problem with sw. > > Sw just need to issue send_command() and done with it, like rest of the commands. > > A pain would be create yet another DMA interface. > > > >> > >> > > > >> > > > > > 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". > >> > Config fields for initialization time is fine as the spec allows it today. > >> > Things which can differ, it is ok to use cvq interface. > >> > >> I don't know what does "Things that can differ" means. Generally device caps > >> are perfect for config space. Accessed at init time only, RO. > >> > > You ignore the comment I answered before that proposal here is not based on RO/RW. > > It is based on initialization time vs run time. > > > >> > > 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. > >> > > > >> > I explained it before, that 6 out of 19 devices has cvq which are complex > >> enough doing things over cvq. > >> > These are non-network devices already. > >> > > >> > If one of those remaining device becomes complex, it is likely it will need a > >> cvq to suffice for the dma interface and it can just do with depth = 1. > >> > >> Using generic caps and not net specific ones is a good idea. > >> > > context here is cvq and net. > > > >> > >> > >> > > > >> > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > 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. > >> > For lot of configuration they are similar that happens at slow pace. > >> > > >> > > Devices commonly use register map. Everyone understands this paradigm. > >> > > > >> > For initialization early device setup time, yes. > >> > > >> > > > >> > > 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. > >> > > >> > For migration, we are not duplicating. Some structures are not well defined, > >> it has some duplication. > >> > >> And fyi it's already making people unhappy. > >> > > Those exceptions are not the interesting one to take as example here. > > > >> > But large part seems be able to utilized pre-defined structs. > >> > And here for flow filter also same structs will be used. > >> > >> So if there's a 64 bit bitmap in config space, then provisioning command which > >> already gets config space can just use its offset. > >> Simpler, better. > >> > > It is not simple to implement per device unique config space as we discussed already. > > And no need another DMA interface either as cvq service that need already. > > A general injection from me. > > We're seeing more and more of those monster threads on the list, where > everything is going in circles, sometimes spawning new versions, which > create their own monster threads... I really dread looking at > virtio-comment nowadays. This is drowning out other things on the list, > which have a tendency to just get lost in the noise. > > We should stop and think, figure out why that happens, and how we can > get back to a productive environment. > > >From what I've seen in this discussion here (and it seems to mirror > other discussions I've browsed), it seems to boil down to narrow > viewpoints and problematic ways of discussing the design. > > Is PCI important? Of course. Is virtio-net important? Nobody disputes > that. Are hardware implementations something we want to support well? > Sure. But that does not mean other use cases are not important as > well. Having a particular use case in mind is completely fine, treating > other use cases as second-class citizens is not. > > What has also stuck out to me in many of those discussions is something > I'll call "argument by assertion", i.e. statements that something is > this-and-that, without qualifiers like "I think that..." or "we've seen > in other instances that...". From what I've seen, this tends to make > people on the other side of the argument defensive instead of > considering the arguments -- it certainly does not seem to foster a > productive discussion, or at least that's my impression. I've also seen > a tendency to reduce arguments to absolutes, which tends to bring out > defensiveness as well. > > Last but not least, I don't think rapid posting is helping -- it rather > just seems to speed up ping-pong posting with each side becoming > entrenched in their point of view even more. It's certainly not > pleasurable to try to follow these threads. Can we try to calm down a > bit, please? Thanks for bringing this up Cornelia, I agree and think I've been guilty of being too assertive and posting too fast recently, too. I'll try to address that. Thanks, -- MST 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/