From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 5B82DD80477 for ; Fri, 27 Oct 2023 10:57:21 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=av7l0zy8Gcq7IstYfuM3AnIf54UoEAMtE5f/ntCq5kA=; c=relaxed/simple; d=groups.io; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:In-Reply-To:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Type:Content-Disposition; s=20140610; t=1698404239; v=1; b=lOHrFWu/uXuY0Bn+UT4Y3pur25HLk7jahdWaj0hBUNHS7+fW5aXgSYXxA/D06anrgtwuXLLl DIpD/civ0a0EtQu4zPW1+ks/f1lgKo8jWEjRYaCgoD7cb1N53UP6GssqqLrkCJgicY1Tx2tXlKv 9Ev/Zn4C/kfOYxOnCc96l5rY= X-Received: by 127.0.0.2 with SMTP id YRj3YY7687511xAOBwjStLts; Fri, 27 Oct 2023 03:57:19 -0700 X-Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mx.groups.io with SMTP id smtpd.web11.4157.1698404239059515273 for ; Fri, 27 Oct 2023 03:57:19 -0700 X-Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-369-Inozb4itMLW8Nj-ps69TJQ-1; Fri, 27 Oct 2023 06:57:13 -0400 X-MC-Unique: Inozb4itMLW8Nj-ps69TJQ-1 X-Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A56423857B7F; Fri, 27 Oct 2023 10:57:12 +0000 (UTC) X-Received: from sirius.home.kraxel.org (unknown [10.39.194.65]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 62A5BC1596D; Fri, 27 Oct 2023 10:57:12 +0000 (UTC) X-Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 05A9518011F2; Fri, 27 Oct 2023 12:57:10 +0200 (CEST) Date: Fri, 27 Oct 2023 12:57:10 +0200 From: "Gerd Hoffmann" To: Laszlo Ersek Cc: Peter Maydell , devel@edk2.groups.io, ardb@kernel.org, Ard Biesheuvel , Julien Grall , Leif Lindholm , Sami Mujawar Subject: Re: [edk2-devel] [PATCH 0/9] ArmVirtPkg: support two PL011 UARTs Message-ID: References: <20231008153912.175941-1-lersek@redhat.com> <35314dd9-3705-d322-4137-f4708d420e3e@redhat.com> <9e698cf7-7e58-b32b-58e9-e18f54736f75@redhat.com> MIME-Version: 1.0 In-Reply-To: <9e698cf7-7e58-b32b-58e9-e18f54736f75@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,kraxel@redhat.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: X-Gm-Message-State: 6cyvKvYWWDxzMQixkSA2BW9bx7686176AA= Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b="lOHrFWu/"; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=redhat.com (policy=none) Hi, > So, for this purpose, only the following could have a chance of working: > > - Expose a new config option on the QEMU command line to the user, > regarding the intended use of the serial port(s). This could be of any > tolerable form (machine property, front-end (device) property, whatever > -- anything that QEMU reviewers can accept). > > - In QEMU, generate both the DT and the ACPI tables accordingly. The > ACPI tables would have to immediately *not* contain the UART-to-hide (so > as to keep it secret from the guest OS). The DT at the same time would > still have to expose the "runtime DEBUG UART", because edk2 would have > to know where that UART was (and that it was meant specifically for OS > runtime debug output). > > - Edk2 would have to patch the DT (we tend to do that already), because > (in some configs) we do forward the DT to the guest OS. This need for > patching could be lifted if QEMU adopted such a form of expression for > the "runtime DEBUG UART" that would be ignored by Linux out of the box. That approach looks best to me. It allows the user to specify on the qemu command line what the ports should be used for, which is IMHO the most convenient option. qemu generates the complete DSDT anyway, so it's trivial to add/remove serial ports there, and for the DT we have libfdt to do the work needed. take care, Gerd -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#110201): https://edk2.groups.io/g/devel/message/110201 Mute This Topic: https://groups.io/mt/101834880/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=-=-=-=-=-=-=-=-=-=-=-