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 B3B53C433F5 for ; Sun, 26 Sep 2021 18:58:28 +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 45E1D60D42 for ; Sun, 26 Sep 2021 18:58:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 45E1D60D42 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:53700 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mUZM3-0001u4-DM for qemu-devel@archiver.kernel.org; Sun, 26 Sep 2021 14:58:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60742) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mUZJW-0008GD-Rc for qemu-devel@nongnu.org; Sun, 26 Sep 2021 14:55:51 -0400 Received: from mail-vs1-xe2c.google.com ([2607:f8b0:4864:20::e2c]:41948) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mUZJT-0006Lz-TD for qemu-devel@nongnu.org; Sun, 26 Sep 2021 14:55:50 -0400 Received: by mail-vs1-xe2c.google.com with SMTP id az15so15727961vsb.8 for ; Sun, 26 Sep 2021 11:55:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=QyG8LUKoiJuona240wxgR1VvYFwuqPXh9SHPqugr1GI=; b=en0k4iwWL3frDbpErMim5v3kb8pR9jooEGCd9sDIxOIVdHJboiyCBmTEkom0Efez48 23LFBtKimCqL3V+6GnXNRfFnuKl5ro3fs4O59eQh0friEwA1/EFnCS9dADVYko95Pu3a YAaOYlNFw0aKVsxzPYvQsnWs6gdwb3JqdpdTU= 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=QyG8LUKoiJuona240wxgR1VvYFwuqPXh9SHPqugr1GI=; b=uZ0cauw7/9nlpu9T8J6TtN5+aD3AvX3+dN82qEg8j+GzyPKXny93TriADh5Eg31Rbh omkb+sXyUUattS7+Jc1MdDroYxktrb4DnlBFuQ2EA3D9wwBTobdmgtLiaVETt8RaNfNv di6MrNFrfjY7dnvUcs6By01Ksvh1//wAHSlQOC8h+SjFs0mgVs6EfTTjHUhnhQ5FId+R bfFJpRglbA+h+xXNGnyAUPMnA8PSVNQnaOa2iR1bhfjFrMwDEQ897FpUd3nU5opGZ2fL LqwaRAxZn9Romem4XIhmI2Y0TQQeDbQIQdx3AH/FQxiWcD+b3rvQV2c84bffTBvd75// qeKw== X-Gm-Message-State: AOAM532GXy8sIOiCHvdKxHUP7zOHv0k/syoaeislVWCfl6B2YnZng9IX lrkg7KPfEmgxPr4LbZN75oYT6u7HOnBjlVLWTsPKqA== X-Google-Smtp-Source: ABdhPJwMN4LDokIOobG3HrUFofZed4KDISiMhoIBsWPdLha3q5bybxvki0d0a54WosEfmBRTDlUm++nAqLfRip1omgs= X-Received: by 2002:a05:6102:3a59:: with SMTP id c25mr16110800vsu.15.1632682543607; Sun, 26 Sep 2021 11:55:43 -0700 (PDT) MIME-Version: 1.0 References: <20210926183410.256484-1-sjg@chromium.org> In-Reply-To: From: Simon Glass Date: Sun, 26 Sep 2021 12:55:32 -0600 Message-ID: Subject: Re: [PATCH] hw/arm/virt: Allow additions to the generated device tree To: Peter Maydell Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::e2c; envelope-from=sjg@google.com; helo=mail-vs1-xe2c.google.com X-Spam_score_int: -92 X-Spam_score: -9.3 X-Spam_bar: --------- X-Spam_report: (-9.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, USER_IN_DEF_SPF_WL=-7.5 autolearn=no 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: Paolo Bonzini , qemu-arm , QEMU Developers , Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Peter, On Sun, 26 Sept 2021 at 12:47, Peter Maydell wrote: > > On Sun, 26 Sept 2021 at 19:34, Simon Glass wrote: > > > > At present qemu creates a device tree automatically with the 'virt' generic > > virtual platform. This is very convenient in most cases but there is not > > much control over what is generated. > > > > Add a way to provide a device tree binary file with additional properties > > to add before booting. This provides flexibility for situations where > > Linux needs some tweak to operate correctly. It also allows configuration > > information to be passed to U-Boot, supporting verified boot, for example. > > So, I'm strongly inclined to say "nope" here. The device > tree virt generates is supposed to entirely describe the > virtual hardware we pass to the guest. If a guest doesn't > work with that, then either we're generating bogus dtb info > or the guest is not handling the dtb we pass it, and one > or the other should be fixed. Thanks for the response. In the case of U-Boot at least, it uses the devicetree for configuration (it is a boot loader, so there is no user space to provide configuration). So the current setup is not sufficient to boot it correctly in all cases. On the other hand, the 'virt' feature is very useful for testing U-Boot, so it would be great to be able to support this. I also forgot to ask about testing, but am happy to add a test if you can give me some pointers. Regards, Simon