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 65AF3C433F5 for ; Wed, 20 Oct 2021 05:29:57 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EF3BD610D0 for ; Wed, 20 Oct 2021 05:29:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EF3BD610D0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:41694 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1md4Al-0005X0-VQ for qemu-devel@archiver.kernel.org; Wed, 20 Oct 2021 01:29:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37422) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1md4A7-0004s0-IL; Wed, 20 Oct 2021 01:29:15 -0400 Received: from mail-il1-x12e.google.com ([2607:f8b0:4864:20::12e]:46952) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1md4A4-0000cQ-Sx; Wed, 20 Oct 2021 01:29:15 -0400 Received: by mail-il1-x12e.google.com with SMTP id w10so20773425ilc.13; Tue, 19 Oct 2021 22:29:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=Qxcmrzz4ItFdZDjpn59T9wdpGJ+IZN0rWSgZn8U7bRo=; b=b5yYh5oTjJAxJAalVOM/T4ju2oRVehQPeWz8hjfC400EAoxsjXlG/Ixk69T9OGbBls MdwQ2E4dCo3lqXz5ovdGwjfTqLWJkfiTQ6Z2X3wgEFo/uSI648f5pGgYMml4jROQT+H0 ZqI7dNmiXWWLMxaHyAxFlNeUtcEb6flNOL8KlDAT1js5Y7xiB3pz4nLyJ1IKl0KXXUL+ Fe4Q//zKQWjnlfr8nEcsTF6AGlhz7Kksn1yMa/QpySOTCZw8YYPrTk+sdbEE4sUAzv8o Wq3Hn/XYKt6uYuvMydrIu30uBCj3GmkXyMMxDuKYTfhWRJY+2HBW8VqfkekPtD5FNaPQ JHnQ== 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:content-transfer-encoding; bh=Qxcmrzz4ItFdZDjpn59T9wdpGJ+IZN0rWSgZn8U7bRo=; b=jyDFYVm/tIfoY2AkgbsnwKcNPacYzLdqGvrcmRDaWxlQU4lwHW/2uJTbW8HInBYjHk f1fvGTZxWBfd9I8T3VC6xl77w4EEgecM4uI5aPpx6d4A6dbaT5up1t/eiTYkqkA7azAo 3Zu+X/J12svTtFRYtl510ew+w0yQIThADJn0NNiclVtTTL2KE9zPD9mvzJtp0TGOmBOl fLqUUQQc29zmHv08Z+22VqFbL0yPw0+M/eAKIrT4NXly67xga4By0SD+BOeZsngq+YVH gMbEl95Nyn0+59KwCptUrH5MAbPEep7Av69PO+qSWO04YMZDwZc+734HUPbv0t1EiweM 4Xzg== X-Gm-Message-State: AOAM533dOC9SsibkWC/O82jMFXjiOuMt0qJ/LeyLqc5qc001Gj5ZSxff 4bCdF/lQSuhNWQpdjcicKZJTUmuNuYa+ztFtl/Y= X-Google-Smtp-Source: ABdhPJzk8zOebbqpu9G0y57mWF9+XSQeJvfSpJdipeIv/g2/yhVAwJyXf4rsdQreIhxAKcmP0KAkgzkSYLmh5MrMpZQ= X-Received: by 2002:a05:6e02:214a:: with SMTP id d10mr22260435ilv.290.1634707750312; Tue, 19 Oct 2021 22:29:10 -0700 (PDT) MIME-Version: 1.0 References: <20211015074627.3957162-1-frank.chang@sifive.com> <3938e703-3000-a11a-a3e6-4a1ffd0e5601@c-sky.com> In-Reply-To: <3938e703-3000-a11a-a3e6-4a1ffd0e5601@c-sky.com> From: Alistair Francis Date: Wed, 20 Oct 2021 15:28:44 +1000 Message-ID: Subject: Re: [PATCH v8 00/78] support vector extension v1.0 To: LIU Zhiwei Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2607:f8b0:4864:20::12e; envelope-from=alistair23@gmail.com; helo=mail-il1-x12e.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Frank Chang , Alistair Francis , "open list:RISC-V" , "qemu-devel@nongnu.org Developers" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Oct 18, 2021 at 7:37 PM LIU Zhiwei wrote: > > Hi Alistair, > > Sorry for the send error. And I have a question about this patch set. Hello Zhiwei, > > Firstly, I totally support the vector v1.0 upstream. Great! > > The concern is how to deal with the v0.7.1 code on QEMU. There are some > products based on the vector v0.7.1, > such as D1 SOC from Allwinner and Xuantie CPU from Alibaba. The Linux > and GCC upstream for D1 is working in progress, > and eventually these projects will support v0.7.1 in some way, probably > as "x-thead-v" (the "thead" stands for Alibaba T-Head). Yep, so QEMU's stance is to only support the latest version of a draft specification. Once a specification moves from draft to frozen we will also only support the frozen spec. I understand that there is hardware with the v0.7.1 of the vector extension. But in QEMU we don't have the resources for RISC-V to maintain multiple sets of draft extensions. Especially the vector extension, which is very different between v0.7.1 and v1.0 (see the 78 patches in this series). I realise this is disappointing for companies and people who have invested in v0.7.1 in QEMU, and I hope it doesn't put anyone off upstream work. Having the v0.7.1 even for a short period of time has been helpful for the vector extension development and related software/tools. > > Maybe we can > > 1. Drop the v0.7.1 support permanently. > > 2. Drop the v0.7.1 temporarily and add it back later. If in the future there is broad community support for v0.7.1 and we can get some more QEMU resources for RISC-V we can re-evaluate v0.7.1 support. But for the time being it will just be dropped. There are a few QEMU releases with v0.7.1 support, so you can use those for development. The v0.7.1 has received a few bug fixes in the upstream code base which will be beneficial for those using it. Sorry about that Alistair > > 3. Do some compatible work for v0.7.1 in the v1.0 patch set. > > Look forward to your idea. Thanks very much. > > Best Regards, > Zhiwei > > On 2021/10/18 =E4=B8=8B=E5=8D=885:01, LIU Zhiwei wrote: > > Hi Alistair, > > > > There is some products based on the vector v0.7.1, such as D1 SOC from > > Allwinner and Xuantie CPU And we have spent a lot of work to > > support vector on QEMU. > > > > > > > > Allwinner > > > >