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 X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E29F5C31E40 for ; Thu, 15 Aug 2019 09:08:49 +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 AEFD52133F for ; Thu, 15 Aug 2019 09:08:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="wBfVWNCI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AEFD52133F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39796 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyBkW-00080z-Gw for qemu-devel@archiver.kernel.org; Thu, 15 Aug 2019 05:08:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42914) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyBjj-0007Tq-7C for qemu-devel@nongnu.org; Thu, 15 Aug 2019 05:08:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hyBjh-0004t7-U0 for qemu-devel@nongnu.org; Thu, 15 Aug 2019 05:07:59 -0400 Received: from mail-oi1-x243.google.com ([2607:f8b0:4864:20::243]:34623) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hyBjh-0004se-OM for qemu-devel@nongnu.org; Thu, 15 Aug 2019 05:07:57 -0400 Received: by mail-oi1-x243.google.com with SMTP id l12so1120117oil.1 for ; Thu, 15 Aug 2019 02:07:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=CksL2Rd8GnSo3oAgBusZJpqmaVBK/FhSThWunfJd6U8=; b=wBfVWNCIF/AWEHegT+JPYKK6a4HIaZP3I1jhQew9szqgD9HlDKsGSUlCWihykMCYAt vSh8lsruvcBoQJ6oLgXbQ1LjPUtHqTJKaBL1P9YvMc1z7NGiMqqSI54AIS6vMuBQfd7y KXerwzfBwOEacOkY+JdMNbSV83KiHF2AiHLovwVJdOMg9oHu9ytzrIQ3k38GhehkJ6ot e1Fjq7BewKJSioMey66/nDjcZSxAkp7np4RH/xNzD8gQMcRz184Vt3S7QEX1sdK8Xf/8 7A+1V5HEk2vOXUi4IsW9mW+R10tPk2PLMjzKWRsEW5gtIg4DqOTHIF72VD7IdfbRsdhF 7p/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=CksL2Rd8GnSo3oAgBusZJpqmaVBK/FhSThWunfJd6U8=; b=GkGbh+M1KwhShd6YjCMXSbfMk0igJExypv5qmdeDqn+4ggegn6lCgxYWTCUE1AyJlW 1OuaJxC8fZiGM49rceaW76fxCd4v2MVfYOJfd2QmN19eC6Yddsx8NFMs0W+8iEUvVGis SXyeKaODCeSzgpYhX51czekcLDfZh4ig6JqNqLI2FWfAO6dYo2lWBIF2/DSPzf4vBzg1 1rFs+2Xl2tcp3qMm9PhLLSXwLJr2MJtAtrNDqwwvu+0ZIOnr4nQ1STUGXiVIkPmaC+YX M1uUcnXum0/SR1qkRRwpcAMgah9VBiDX6EmsMGGXWD+VnBtcumnQvFwxouiJ+jAx2Kbd sbCg== X-Gm-Message-State: APjAAAVVWzzQBKJyxLQ1XGxWPJBF/CwQcFWXIhfOeU2cK1XnozFy/ye6 2VKZbPZpZ9WBUfFV19lRDi2ztOz2lo/sqzl8+bF77w== X-Google-Smtp-Source: APXvYqwjmNZ3wh2syUcMDloczheJykmHZIm94YuTV3VF6bJW5JR447sxx9AIPERtJjAK/51s9ST+ubiN4TeUiHJz1sc= X-Received: by 2002:aca:4a57:: with SMTP id x84mr918050oia.170.1565860076715; Thu, 15 Aug 2019 02:07:56 -0700 (PDT) MIME-Version: 1.0 References: <97a6ae9f-2845-4a3c-2a31-367787622268@c-sky.com> In-Reply-To: From: Peter Maydell Date: Thu, 15 Aug 2019 10:07:45 +0100 Message-ID: To: Aleksandar Markovic Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::243 Subject: Re: [Qemu-devel] RISC-V: Vector && DSP Extension 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: "open list:RISC-V" , Sagar Karandikar , bastian@mail.uni-paderborn.de, Palmer Dabbelt , "qemu-devel@nongnu.org Developers" , Alistair Francis , Alistair Francis , LIU ZhiWei Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 15 Aug 2019 at 09:53, Aleksandar Markovic wrote: > > > We can accept draft > > extensions in QEMU as long as they are disabled by default. > Hi, Alistair, Palmer, > > Is this an official stance of QEMU community, or perhaps Alistair's > personal judgement, or maybe a rule within risv subcomunity? Alistair asked on a previous thread; my view was: https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg03364.html and nobody else spoke up disagreeing (summary: should at least be disabled-by-default and only enabled by setting an explicit property whose name should start with the 'x-' prefix). In general QEMU does sometimes introduce experimental extensions (we've had them in the block layer, for example) and so the 'x-' property to enable them is a reasonably established convention. I think it's a reasonable compromise to allow this sort of work to start and not have to live out-of-tree for a long time, without confusing users or getting into a situation where some QEMU versions behave differently or to obsolete drafts of a spec without it being clear from the command line that experimental extensions are being enabled. There is also an element of "submaintainer judgement" to be applied here -- upstream is probably not the place for a draft extension to be implemented if it is: * still fast moving or subject to major changes of design direction * major changes to the codebase (especially if it requires changes to core code) that might later need to be redone entirely differently * still experimental thanks -- PMM From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1hyBjm-0007Uk-Ew for mharc-qemu-riscv@gnu.org; Thu, 15 Aug 2019 05:08:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42913) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyBjj-0007Tp-5q for qemu-riscv@nongnu.org; Thu, 15 Aug 2019 05:08:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hyBjh-0004tD-Ua for qemu-riscv@nongnu.org; Thu, 15 Aug 2019 05:07:59 -0400 Received: from mail-oi1-x244.google.com ([2607:f8b0:4864:20::244]:42460) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hyBjh-0004sg-OP for qemu-riscv@nongnu.org; Thu, 15 Aug 2019 05:07:57 -0400 Received: by mail-oi1-x244.google.com with SMTP id o6so1085018oic.9 for ; Thu, 15 Aug 2019 02:07:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=CksL2Rd8GnSo3oAgBusZJpqmaVBK/FhSThWunfJd6U8=; b=wBfVWNCIF/AWEHegT+JPYKK6a4HIaZP3I1jhQew9szqgD9HlDKsGSUlCWihykMCYAt vSh8lsruvcBoQJ6oLgXbQ1LjPUtHqTJKaBL1P9YvMc1z7NGiMqqSI54AIS6vMuBQfd7y KXerwzfBwOEacOkY+JdMNbSV83KiHF2AiHLovwVJdOMg9oHu9ytzrIQ3k38GhehkJ6ot e1Fjq7BewKJSioMey66/nDjcZSxAkp7np4RH/xNzD8gQMcRz184Vt3S7QEX1sdK8Xf/8 7A+1V5HEk2vOXUi4IsW9mW+R10tPk2PLMjzKWRsEW5gtIg4DqOTHIF72VD7IdfbRsdhF 7p/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=CksL2Rd8GnSo3oAgBusZJpqmaVBK/FhSThWunfJd6U8=; b=bzYw5r8Adf4CwCwuKtjz8kwZwiljuGLpvMVN9td77fXt+0DJUv+i8uuD4BpY/igRKf b4QnDwlF5Wn58wGxzu7wZHQBdf1wD9ShUiOW24xI1mu31s4ZdH6NyBMbZ4OuokjAT8wH RiWknm+EW3ND6jmY/MAuU6nSVNlOLJ5HIhyKvX4/npySF1rb3RNTWd3ky37dJ3Z9+K7M DdMmHGT6sQ24pYPmCgbseFOkBgscAed9gBp3ROdqCXTTuwyef9iRBU1mZOgwLehyFvX8 mAc5CZXT7nN8MDgbwnaxMXQHDgaSyKXni2hs7/Yv7fkVGL6Q4HuPYhT0C//1J2BvlEy5 zaVw== X-Gm-Message-State: APjAAAWmFjrv2jJnlwMrd6BMkXvCi5NyTTjqlj63wTrK3D0Lgb0fvXBd YyfZ3fQ0pXKxROtsCWYrm6cyvRKk3FwBDtR+6I6LlQ== X-Google-Smtp-Source: APXvYqwjmNZ3wh2syUcMDloczheJykmHZIm94YuTV3VF6bJW5JR447sxx9AIPERtJjAK/51s9ST+ubiN4TeUiHJz1sc= X-Received: by 2002:aca:4a57:: with SMTP id x84mr918050oia.170.1565860076715; Thu, 15 Aug 2019 02:07:56 -0700 (PDT) MIME-Version: 1.0 References: <97a6ae9f-2845-4a3c-2a31-367787622268@c-sky.com> In-Reply-To: From: Peter Maydell Date: Thu, 15 Aug 2019 10:07:45 +0100 Message-ID: To: Aleksandar Markovic Cc: Alistair Francis , "open list:RISC-V" , Sagar Karandikar , bastian@mail.uni-paderborn.de, Palmer Dabbelt , "qemu-devel@nongnu.org Developers" , Alistair Francis , LIU ZhiWei Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::244 Subject: Re: [Qemu-riscv] [Qemu-devel] RISC-V: Vector && DSP Extension X-BeenThere: qemu-riscv@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Aug 2019 09:08:00 -0000 On Thu, 15 Aug 2019 at 09:53, Aleksandar Markovic wrote: > > > We can accept draft > > extensions in QEMU as long as they are disabled by default. > Hi, Alistair, Palmer, > > Is this an official stance of QEMU community, or perhaps Alistair's > personal judgement, or maybe a rule within risv subcomunity? Alistair asked on a previous thread; my view was: https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg03364.html and nobody else spoke up disagreeing (summary: should at least be disabled-by-default and only enabled by setting an explicit property whose name should start with the 'x-' prefix). In general QEMU does sometimes introduce experimental extensions (we've had them in the block layer, for example) and so the 'x-' property to enable them is a reasonably established convention. I think it's a reasonable compromise to allow this sort of work to start and not have to live out-of-tree for a long time, without confusing users or getting into a situation where some QEMU versions behave differently or to obsolete drafts of a spec without it being clear from the command line that experimental extensions are being enabled. There is also an element of "submaintainer judgement" to be applied here -- upstream is probably not the place for a draft extension to be implemented if it is: * still fast moving or subject to major changes of design direction * major changes to the codebase (especially if it requires changes to core code) that might later need to be redone entirely differently * still experimental thanks -- PMM