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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 33D2EC0218A for ; Tue, 28 Jan 2025 09:18:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tchj3-00051a-Gq; Tue, 28 Jan 2025 04:17:41 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tchj0-00050f-Kd for qemu-devel@nongnu.org; Tue, 28 Jan 2025 04:17:38 -0500 Received: from mail-wm1-x332.google.com ([2a00:1450:4864:20::332]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tchiy-0001pF-RT for qemu-devel@nongnu.org; Tue, 28 Jan 2025 04:17:38 -0500 Received: by mail-wm1-x332.google.com with SMTP id 5b1f17b1804b1-43634b570c1so37551695e9.0 for ; Tue, 28 Jan 2025 01:17:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1738055855; x=1738660655; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=cNtuBqPW6c9cGsDa+hKWe5shvr9uttKboQwbuz++lMU=; b=mRYWJ/LPTf1N7Hcu05zOsAV9NJgxVkaAADn8ThFINtT/Pk8li7qYXptgAYntq8RNTZ 8cLSrr0gjoFqjcVujz2i0OuVdI3LeOTBsDZpRNmT1iIGFiUDscCCkB/YIsGzqs/ms9sB aHlyJWYV8Q4IgvHjpd0tHuNRPIomLTsKY8wI8UkilbNmiU9ULIDTExi7cVajKXbZZsDE xM+FvhZ00XddQlY1vod+nMsToe+2jetiqRMuprAlAW+M2Uuya9f+RIcA4UPGGCWAY4fB 3KCugyCZTy8Q7scmI3LWQNTvjVLk8x2jGFcDhKYILW5BkPpuIAGQy+cOvMBwH5Fi3pB8 sJ0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738055855; x=1738660655; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cNtuBqPW6c9cGsDa+hKWe5shvr9uttKboQwbuz++lMU=; b=YFholO1pAKVAATrXWbrPtCbDNu0zTxzUYOg4nMvDmSJbb6VXLEKDvGVc8FNOsjWKtd 4ANs0UJBf4A+inAiQYzG3iZ9o5fzzneLiQVV5OJi6fwXf2b5BNWcJyCCkIfaZ19yauFO ZMZ6l+13K75wLONHw36vMms2g27CfE+mxNVyNJ+dHWKsl9Cu1+z33BftT4pdKFnucF2p cWwJvClaZoam/FxgZLf8jEwk5Mc3kiSNsMXt2sXcEGx7hMA9mkc/gLWbkGzjGYXgTxMt fWVtmf7wFpLn4a1w9D6u2Ogi0zqsye5iL7bffKcREMnyS9jCjBw4MMRNcwApKBmwTryw VLNA== X-Forwarded-Encrypted: i=1; AJvYcCVzDHdBrtpcfafGfPvoP6scVAWjOdunVUdeW11zxaMCI9xCuC7wWTc8y5pCOQEFxMOrDlwgjVEqYRHa@nongnu.org X-Gm-Message-State: AOJu0YwLHC7gIvGzZF6svsDaZCdZ9UDzoEDisJ5kI/K0gBfZAlyHVwNt djy5M8axisd75qoHyQrLSkusTzZ/Eo88wHoIJuMjGylTRgL4/cAiBGzyP8uUDTU= X-Gm-Gg: ASbGnct7t/EMA/UjUcyaGQOVZ5WYeIpfqLX0o8fdY3nLFjgm5cj+mS6Mq54rVJV3wCN GQt+DPeIbem9DJhto+uPOFKVtr7TUECb3RFIi7pEb7e2qKEoSRpCxR7aXL2e2mdv7xT0xe8sIlQ 8ogYV3d7wEYO7TY/l5Q5Kxwflh07Sku0pS7/JYXJ8afNNrtSIC9tBJM8nesgq3IqEen/VRUlx3o hxCU1St+WYhbZn5BCCud5+m7Piuu1K2QI05s1giArlRQbamEJmGgH4lY8TtS5cHs44C8I/yC/3g wolCBAfSozKzBsOokenoH5r53tLLI/dGc45oAk3BLkaULwxccAyWi+ZoONI= X-Google-Smtp-Source: AGHT+IFxiTHWw+9Dhvf7WfuqAFtc/jHgIpSFNYll/6X0dyxDEjA0iwDQ6YdYGKTvUQ6bCD07agvmeA== X-Received: by 2002:a05:600c:6550:b0:434:f3d8:62d0 with SMTP id 5b1f17b1804b1-438946434dcmr385202725e9.3.1738055854830; Tue, 28 Jan 2025 01:17:34 -0800 (PST) Received: from [192.168.69.151] (88-187-86-199.subs.proxad.net. [88.187.86.199]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-438bd4fa479sm165685615e9.5.2025.01.28.01.17.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Jan 2025 01:17:34 -0800 (PST) Message-ID: Date: Tue, 28 Jan 2025 10:17:33 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/1] meson: Deprecate 32-bit host systems To: =?UTF-8?Q?Alex_Benn=C3=A9e?= , Thomas Huth Cc: Richard Henderson , qemu-devel@nongnu.org, peter.maydell@linaro.org, stefanha@redhat.com, pbonzini@redhat.com, berrange@redhat.com, mark.cave-ayland@ilande.co.uk, Liviu Ionescu References: <20250128004254.33442-1-richard.henderson@linaro.org> <9a280789-9248-4eca-b50c-048fc58e3f53@redhat.com> <87plk72tvr.fsf@draig.linaro.org> Content-Language: en-US From: =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= In-Reply-To: <87plk72tvr.fsf@draig.linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::332; envelope-from=philmd@linaro.org; helo=mail-wm1-x332.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 28/1/25 10:02, Alex Bennée wrote: > Thomas Huth writes: > >> On 28/01/2025 01.42, Richard Henderson wrote: >>> Time for our biennial attempt to kill ancient hosts. >>> I've been re-working the tcg code generator a bit over the holidays. >>> One place that screams for a bit of cleanup is with 64-bit guest >>> addresses on 32-bit hosts. Of course the best "cleanup" is to not >>> have to handle such silliness at all. >>> Two years after Thomas' last attempt, >>> https://lore.kernel.org/qemu-devel/20230130114428.1297295-1-thuth@redhat.com/ >>> which resulted only in deprecation of i686 host for system >>> emulation. >>> By itself, this just isn't enough for large-scale cleanups. >>> I'll note that we've separately deprecated mips32, set to expire >>> with the end of Debian bookworm, set to enter LTS in June 2026. >>> I'll note that there is *already* no Debian support for ppc32, >>> and that I am currently unable to cross-compile that host at all. >> >> IIRC the biggest pushback that I got two years ago was with regards to >> 32-bit arm: The recommended version of Raspberry Pi OS is still >> 32-bit: >> >> https://lore.kernel.org/qemu-devel/F852C238-77B8-4E24-9494-8D060EB78F9F@livius.net/ >> >> And looking at https://www.raspberrypi.com/software/operating-systems/ >> this still seems to be the case... >> >> So I guess the main question is now: Would it be ok to kill support >> for 32-bit Raspberry Pi OS nowadays? > > I would argue yes for a few reasons. > > - you can't buy 32 bit only Pi's AFAICT, even the Pi Zero 2W can work > with a 64 bit OS. > > - It's not like the versions shipping in bullseye and bookworm will > stop working. > > - Even if we deprecate now there will likely be one more Debian > release cycle that gets 32 bit host support. > >>> Showing my hand a bit, I am willing to limit deprecation to >>> 64-bit guests on 32-bit hosts. But I'd prefer to go the whole hog: >>> unconditional support for TCG_TYPE_I64 would remove a *lot* of >>> 32-bit fallback code. > > I support going the whole hog. I would be curious what use cases still > exist for an up to date 32-on-32 QEMU based emulation? Current maintainers don't have spare time to support the 32-on-32 emulation. If there is interest in the community for such niche, someone needs to step forward, willing to maintain it.