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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A78B9C433EF for ; Thu, 30 Sep 2021 15:17:00 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 04A726135D for ; Thu, 30 Sep 2021 15:16:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 04A726135D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=riscv.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.denx.de Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 080D383162; Thu, 30 Sep 2021 17:16:50 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=riscv.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=riscv-org.20210112.gappssmtp.com header.i=@riscv-org.20210112.gappssmtp.com header.b="kdLtaqU3"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 5842682127; Thu, 30 Sep 2021 17:06:59 +0200 (CEST) Received: from mail-vs1-xe2a.google.com (mail-vs1-xe2a.google.com [IPv6:2607:f8b0:4864:20::e2a]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 5AF378035E for ; Thu, 30 Sep 2021 17:06:54 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=riscv.org Authentication-Results: phobos.denx.de; spf=none smtp.mailfrom=markhimelstein@riscv.org Received: by mail-vs1-xe2a.google.com with SMTP id x1so7694274vsp.12 for ; Thu, 30 Sep 2021 08:06:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=riscv-org.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oWZELkT5kE+U+lbYtiDQglRaTMps0Uh2Jptjao9fy6A=; b=kdLtaqU3Q+m40+3/l7rxxQb2QWQ5Rx4qhhqWnQlv+aWy3S+/Lt07jvCSeQH8kByZmn UdSOvCbSU3Hx2ya2uryYP/El+2jcKTUad1PBjy9lMZwezSyQqblP1oJyK80XClCbQoXU Wcdcp/T51FUBEc6kNRplFdoiqU2xGlDOYc/iF1RqYiGTLYo0ppKO40gF9Fc2pMdHGBHE 9tUt36SA78J7KUQ8cJzKoJ+aPH6TOn5MThhHewLmwgFheZKs0FTaIkunwtd4+lxcTwXb yvbiKTFQrMkBing2RjM9RUtkOEKTWHwRZZUVylLIpMPOoS1JlalV5FNjH6DsgIP6H4L6 PS8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oWZELkT5kE+U+lbYtiDQglRaTMps0Uh2Jptjao9fy6A=; b=2nZYSR367Uq3IVCwtViQRqR1vpcUbnxQLYAbfDGBI7jYoQfYCOe1ezWltrRWTRrKlc b+3XV+P78Q/+0hWNPJvx4RW9bry80ZeZA5BP7UIq7ng6hEHXuKpS9M4s9zZTqveB6c4a 8g+rcbJx7Qm42sPrfPQgw+tpmzgFMGk6iMlGgDmaC+zPngO1vaFiig7nOMbaOukF2j6s 1sXyPuAA51HH/EmtH08PR7HsTLGak9fM7/MmCIHlQEo1tSKjzpW9oirubYNe77mmE+Un AfJ2L2QtTT+aLzXuvoJYko9mxGPdqEhNn6lCmFTaHM0k8UIbcPr0fTnoCXd+ZN1u5wMo DvRg== X-Gm-Message-State: AOAM531oAV9uvzBi5oz+H7XAgpPNJTX+nAqrhNgNYYB6BbbJbStoas1L aY5xOKFYc1cKECZ9E+8A7YlL6D6LNnTB/qq2DKi3Pg== X-Google-Smtp-Source: ABdhPJwkhcmcIuNg1UKrz4DSvjRh+asRFxDckK3wMpgynCeBMQHwsvCYH0VkYfBwUYsD9/G4etOywEk4+7Jc+MT8TZQ= X-Received: by 2002:a67:ee12:: with SMTP id f18mr3975315vsp.20.1633014412897; Thu, 30 Sep 2021 08:06:52 -0700 (PDT) MIME-Version: 1.0 References: <63E6E860-22F0-457D-B17B-3B6625BA4A99@riscv.org> In-Reply-To: From: Mark Himelstein Date: Thu, 30 Sep 2021 08:06:42 -0700 Message-ID: Subject: Re: Status of the various RISC-V specification and policy To: Palmer Dabbelt Cc: Atish Patra , linux-riscv@lists.infradead.org, u-boot@lists.denx.de, al stone , Paolo Bonzini , Christoph Hellwig , Andrew Jones , xypron.glpk@gmx.de, Fu Wei , Paul Walmsley , Kumar Sankaran , Philipp Tomsich , Anup Patel , Stephano Cetola X-Mailman-Approved-At: Thu, 30 Sep 2021 17:16:38 +0200 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean Palmer, Thank you for your input. Our strong intention is to not change specs once frozen. I speak for the committees here and say that, in our opinion, declaring something frozen sets a very high bar for making any changes and is sufficient to allow code supporting an extension to be upstreamed. Of course if an unexpected and significant issue is discovered during the public review that absolutely must be addressed and cannot be deferred to a future extension (where the cost of not addressing the issue exceeds the cost of addressing it. for example introduces security vulnerabilities), then we will do so, as anyone should expect from a public review. We do not have versions of extensions. If an extension has a problem once ratified, we will issue errata. All implementers have to publish the errata if they use branding. We may release a new extension with the bulk of the original extension plus the errata fix at some future date. New extensions reserve the right to be incompatible with existing extensions but our philosophy is very much to minimize that and only allow the rare well-justified exceptions. Reasons may include errata, security issues discovered, or new functionality we need to add that justifies creating an incompatibility, etc. What specifically do you see as an issue? What are you blocked on by our conventions? We need specific details to resolve any issues. Right now, I don't feel I have enough information from you. Thanks Mark P.S. We had some situations in the past, in part due to vendors not waiting for the specification processes to conclude, where implementers implemented non-confoming chips either with vendor-specific extensions using reserved opcodes and state, or implementing early drafts of standards-track proposals in the development state (will likely change). This is in the past and resolved. Anyone implementing non-standard extensions must advertise them as such and make it clear that these are not standard RISC-V extensions: this should make it clear for upstream projects that they will be dealing with the respective vendors for support and maintenance, and that any code implementing support for these extensions will be different from what covers the respective standard extensions. Whether upstream projects accept such changes, and what conditions they stipulate for acceptance of these changes, are beyond the control of RISC-V. We also, as I have described to you many times, have instituted mandatory standards specification states for the front page of each specification to ensure clarity (any divergence from this is a bug and we work to fix these quickly). On Tue, Sep 28, 2021 at 11:34 AM Palmer Dabbelt wrote: > On Mon, 27 Sep 2021 08:57:15 PDT (-0700), markhimelstein@riscv.org wrote: > > the words in this document : > > > > > https://wiki.riscv.org/plugins/servlet/mobile?contentId=3D13098230#conten= t/view/13098230 > > > > make it very clear when changes are allowed or not and likely or not. > > > > if you think the verbiage is somehow ambiguous please help us make it > better. > > I'm not really worried about changes, I'm worried about a committment to > future compatibility. When we take code into the kernel (and most other > core systems projects) we're taking on the burden of supporting (until > someone can prove there are no more users), which is very difficult to > do when the ISA changes in an incompatible fashion. The whole point of > agreeing on the frozen thing was that it gave us a committment from the > specifcation authors that the future ISA would be compatible with th > frozen extensions. > > We're already in this spot with the V extension and the whole stable > thing, this definitaion of frozen looks very much like what was has led > to the issues there. Saying the spec won't change really isn't > meaningful, it's saying future specs will be compatible that's > important. Nothing in this whole rule touches on compatibility, and I > really don't want to end up in a bigger mess than we're already in. > > (Also: some PGE subcontractor drove a crane into my house, so things are > a bit chaotic on my end. If you have that list of what's officially > frozen, can you send it out? I'll try to take a look ASAP, as then I > can at least focus the discussion on what's relevant right now.) > > > > > Mark > > -------- > > sent from a mobile device. please forgive any typos. > > > >> On Sep 27, 2021, at 8:50 AM, Palmer Dabbelt wrote= : > >> > >> =EF=BB=BFOn Tue, 21 Sep 2021 17:20:17 PDT (-0700), atishp@atishpatra.o= rg wrote: > >>> Hi All, > >>> Please find the below email from Stephano about the freeze > announcement for > >>> various RISC-V specifications that will be part of privilege > specification > >>> v1.12. > >>> All the review discussions are happening in the isa-dev mailing list. > The > >>> review period will be open for 45 days ending Sunday October 31, 2021= . > >>> > >>> I just want to highlight the fact that the *H*, *V, SvPBMT, CMO > extensions > >>> are frozen now. *This will help us merge some patches that have been > >>> present in the mailing list for a while. > >>> > >>> Here are the ratification policy and extension life cycle documents > present > >>> in the public. If you have any questions regarding this, please check > with > >>> Mark/Stephano (cc'd). > >>> > >>> Ratification policy: > >>> > https://docs.google.com/document/d/1-UlaSGqk59_myeuPMrV9gyuaIgnmFzGh5Gfy_= tpViwM/edit > >>> > >>> Extension life cycle: > >>> > https://docs.google.com/presentation/d/1nQ5uFb39KA6gvUi5SReWfIQSiRN7hp6z7= ZPfctE4mKk/edit#slide=3Did.p1 > >> > >> I'm still buried after Plumbers, but one of the bits on my TODO list > was to look throught the new definitions for frozen and stable. Nothing = in > this extension life cycle talks about the point at which compatibility wi= ll > be maintained, which was really the central point behind frozen before. > >> > >> Are there more concrete definitions somewhere? >