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 359C7C47DD9 for ; Mon, 22 Jan 2024 17:47:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rRyNe-0002jD-0n; Mon, 22 Jan 2024 12:46:42 -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 1rRyNc-0002iQ-Da for qemu-devel@nongnu.org; Mon, 22 Jan 2024 12:46:40 -0500 Received: from mail-ot1-x32a.google.com ([2607:f8b0:4864:20::32a]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rRyNa-0005Dr-SJ for qemu-devel@nongnu.org; Mon, 22 Jan 2024 12:46:40 -0500 Received: by mail-ot1-x32a.google.com with SMTP id 46e09a7af769-6dc36e501e1so3127707a34.1 for ; Mon, 22 Jan 2024 09:46:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1705945596; x=1706550396; darn=nongnu.org; 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=6tJKN90fYoTF+wPqjbzqzOdyVCh676j3Po9ZwYKNXDk=; b=UuwdD/b/O5+EQFGHXmXYJH7dk7LPTE3GACu/Jz/dg4OX40cHqBP9MaSult3oXmTUHM xsuR/edftK8L09WGasJ8qF6tp8IKmhLIEsAXzS6ZbPN60f0rOdsaBHeGrA+Qx4TJ86km mhOaS5PMp/pwrOKKNPe75wKOP7uaBu8JMV0B+gR4ymeVXijtx835mP9lJ7aQF4fhOkps Kb9JVZAED27V5OQaztFNzX6ouXUWm+miIO0OZWclQKIIM+vetzzfp+grmjMWjRTew9ZE GnDiPJBfoQYJMvd5WcvqDB5JTHf8VYZ2oNNxmqviSvOIGnt0K4BVSkisima/gps5OqeW diFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705945596; x=1706550396; 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=6tJKN90fYoTF+wPqjbzqzOdyVCh676j3Po9ZwYKNXDk=; b=wmhnnt1YPAWxyoreGoQZhDpT2XIfZp1nld+C2eRIuP6fDPVa0MdPpBfg8GUaQOPYaV kWJBUKh33MjuWyg3Kg2Yhou32btatJkpIFFAktNO97OUHSIz/QlLu+W/NgbVVsiMO2gI ex9eGQxWJZrnEYyQth543A5XBNEwOngFDaMJt4QOEGVFEDCvR1o3PSUggvhIV7/SYGsC XoG2bhyer0+G/tAw4dK3eM1LKUkgh741JXzK2WXKmzeinX1OB6V214GXjtYrGcszJk92 BDtpE+iEYhP2bgj6idMrOYnubR5rubGonl1MLPl7+NCc9+HdI9YqFaX/09OnHk1vLshD EAuQ== X-Gm-Message-State: AOJu0Yz7c3QIezruGB2wd5Kx6aQoYnjkMm5Gl+WQKD04Cp5A2am5QARt fM0f1068BMe/AEp4rhSnwziDSuYetSiywrYm6hIUcPRNdpX47FLCFA3Uc/YrwCU= X-Google-Smtp-Source: AGHT+IGDg/WaIgPPFZMIeRvbYYb9xONLYdj1pbo/qGLSade2y258uqLJnovbdrVMK/rPCzQRPGlVTQ== X-Received: by 2002:a9d:5c0c:0:b0:6dc:224:21ca with SMTP id o12-20020a9d5c0c000000b006dc022421camr5340840otk.73.1705945596419; Mon, 22 Jan 2024 09:46:36 -0800 (PST) Received: from [192.168.69.100] ([176.187.194.57]) by smtp.gmail.com with ESMTPSA id y9-20020a9d5189000000b006e0d91a32b9sm1451427otg.0.2024.01.22.09.46.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Jan 2024 09:46:35 -0800 (PST) Message-ID: Date: Mon, 22 Jan 2024 18:46:32 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] qemu-options.hx: Improve -serial option documentation Content-Language: en-US To: Peter Maydell , qemu-devel@nongnu.org, Thomas Huth Cc: qemu-stable@nongnu.org, Bohdan Kostiv , Markus Armbruster , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= References: <20240122163607.459769-1-peter.maydell@linaro.org> <20240122163607.459769-3-peter.maydell@linaro.org> From: =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= In-Reply-To: <20240122163607.459769-3-peter.maydell@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::32a; envelope-from=philmd@linaro.org; helo=mail-ot1-x32a.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 Hi, On 22/1/24 17:36, Peter Maydell wrote: > The -serial option documentation is a bit brief about '-serial none' > and '-serial null'. In particular it's not very clear about the > difference between them, and it doesn't mention that it's up to > the machine model whether '-serial none' means "don't create the > serial port" or "don't wire the serial port up to anything". > > Expand on these points. > > Signed-off-by: Peter Maydell > --- > qemu-options.hx | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/qemu-options.hx b/qemu-options.hx > index ced82848637..d8c3fe91de1 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -4129,7 +4129,8 @@ SRST > This option can be used several times to simulate up to 4 serial > ports. > > - Use ``-serial none`` to disable all serial ports. > + You can use ``-serial none`` to suppress the creation of default > + serial devices. > > Available character devices are: > > @@ -4151,10 +4152,17 @@ SRST > [Linux only] Pseudo TTY (a new PTY is automatically allocated) > > ``none`` > - No device is allocated. > + No device is allocated. Note that > for machine types which > + emulate systems where a serial device is always present in > + real hardware, this may be equivalent to the ``null`` option, > + in that the serial device is still present but all output > + is discarded. Should we deprecate this broken case, suggesting to use ``null`` instead? > For boards where the number of serial ports is > + truly variable, this suppresses the creation of the device. > > ``null`` > - void device > + A guest will see the UART or serial device as present in the > + machine, but all output is discarded, and there is no input. > + Conceptually equivalent to redirecting the output to ``/dev/null``. > > ``chardev:id`` > Use a named character device defined with the ``-chardev`` Reviewed-by: Philippe Mathieu-Daudé