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 644D8C636CD for ; Tue, 7 Feb 2023 08:51:05 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pPJgU-0004jC-H2; Tue, 07 Feb 2023 03:50:38 -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 1pPJgT-0004iu-Bg for qemu-devel@nongnu.org; Tue, 07 Feb 2023 03:50:37 -0500 Received: from mail-wr1-x42f.google.com ([2a00:1450:4864:20::42f]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pPJgR-0004rq-Mh for qemu-devel@nongnu.org; Tue, 07 Feb 2023 03:50:37 -0500 Received: by mail-wr1-x42f.google.com with SMTP id o18so12783970wrj.3 for ; Tue, 07 Feb 2023 00:50:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=c1wmpMStD/at9Qj/mIVfu7+yS5fkgnfmx9smMKOa9n4=; b=JNZV05op4HZda2dO+T7sXrKklXCA3ArqGLpc8Ptv0ANHINIz+Fc3kxqu6saadoiXTc mM6tOt9FLQgxvIsDTlpTgvqFlasQtblVwL+8QAH/O1OCfh0333ZXkOJTQSpGlkQQDy6n +TFkfl4zZIauavauuRzfIfgDxLGh873q46O87RxJ/nH81bNncpFASiNx3llNENxRHIaG lnfpORUrd2ZaKtiwIyHl9L+5g/fdzDzMwyS2mvWvnNKGMwAnj5aA78esVLmYnihOmumi qDFVMn8bCyhPTFD+AmC+wjDNUH6kxlZ8CDzi+WiWKIV0Pn1VQpSH+vtI4Eadofj6fuqf /1RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=c1wmpMStD/at9Qj/mIVfu7+yS5fkgnfmx9smMKOa9n4=; b=U+8XzCwUkG+nrxJWrvPAF8Sq4XiGiFEK5EPWPkKPLfbeLK1WnxiQJVt/ELWzVgr+Tu zo2lEkf8vGGyFGWWJZjsU71W9jEHvyVO0THfwJMW1MkOwPSOMaSFv29acYXa7YPr6bWf dEjcyKj/y5mPlYEgscp/zAFTy6SYHi6LvvT21PSnZWgu6HDjpBGDV0ahDYhT5bpWjA9A oCthqea+X1xfRxmrScN6DyKXnVOU//pY/HWDJOmUi3DvHzoXLjXChDZ1v+CuOxZVPIMl P8WyWuDus+AqBmlH7JUhfuD6IN3TCJ/RuX/Ocgrz/2v3KZV+p28xFIxydNq5DOYU8aMu ZCWw== X-Gm-Message-State: AO0yUKWj5YkKm5MSMCzhVeSWMWYscV2YYYxaeuYIzOmjCUPTOJ8onxV8 SDbzYXfd2mezoyaL6fEhTR0u4g== X-Google-Smtp-Source: AK7set+OiaqMBt/0rAMpqmjdCAdv7ULdCafuzt+SgiC5oqd3/qc6ucj5W3byVft44lMQ9guJDZ+eWQ== X-Received: by 2002:a5d:6dcb:0:b0:2c3:be89:7c3c with SMTP id d11-20020a5d6dcb000000b002c3be897c3cmr10196251wrz.31.1675759833294; Tue, 07 Feb 2023 00:50:33 -0800 (PST) Received: from [192.168.30.216] ([81.0.6.76]) by smtp.gmail.com with ESMTPSA id s2-20020a5d69c2000000b002c3de83be0csm7965965wrw.87.2023.02.07.00.50.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 07 Feb 2023 00:50:31 -0800 (PST) Message-ID: <25504aa3-20e3-d7e6-4111-c956370949ba@linaro.org> Date: Tue, 7 Feb 2023 09:50:29 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH 02/10] hw/riscv/virt: Add a switch to enable/disable ACPI Content-Language: en-US To: Gerd Hoffmann Cc: Andrea Bolognani , Sunil V L , Palmer Dabbelt , Alistair Francis , Bin Meng , qemu-riscv@nongnu.org, qemu-devel@nongnu.org, Andrew Jones , Anup Patel , Atish Kumar Patra , Ani Sinha , "Michael S. Tsirkin" , Markus Armbruster , Igor Mammedov , Thomas Huth , Bernhard Beschow References: <20230202045223.2594627-1-sunilvl@ventanamicro.com> <20230202045223.2594627-3-sunilvl@ventanamicro.com> <20230206125610.nmo2bbbd5kosihav@sirius.home.kraxel.org> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= In-Reply-To: <20230206125610.nmo2bbbd5kosihav@sirius.home.kraxel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::42f; envelope-from=philmd@linaro.org; helo=mail-wr1-x42f.google.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 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, NICE_REPLY_A=-1.148, 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: 2.1.29 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 6/2/23 13:56, Gerd Hoffmann wrote: > On Mon, Feb 06, 2023 at 12:18:06PM +0100, Philippe Mathieu-Daudé wrote: >> On 6/2/23 11:54, Andrea Bolognani wrote: >>> On Thu, Feb 02, 2023 at 10:22:15AM +0530, Sunil V L wrote: >>>> + object_class_property_add(oc, "acpi", "OnOffAuto", >>>> + virt_get_acpi, virt_set_acpi, >>>> + NULL, NULL); >>>> + object_class_property_set_description(oc, "acpi", >>>> + "Enable ACPI"); >>> >>> The way this works on other architectures (x86_64, aarch64) is that >>> you get ACPI by default and can use -no-acpi to disable it if >>> desired. Can we have the same on RISC-V, for consistency? >> >> -no-acpi rather seems a x86-specific hack for the ISA PC machine, and >> has a high maintenance cost / burden. > > Under the hood it is actually a OnOffAuto machine property and -no-acpi > is just a shortcut to set that. > >> Actually, what is the value added by '-no-acpi'? > > On arm(64) the linux kernel can use either device trees or ACPI to find > the hardware. Historical reasons mostly, when the platform started > there was no ACPI support. Also the edk2 firmware uses Device Trees > for hardware discovery, likewise for historical reasons. > > When ACPI is available for a platform right from the start I see little > reason to offer an option to turn it off though ... Yeah I concur. There is no point in disabling ACPI on the RISCV virt machine IMO.