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 1EB76C4167B for ; Mon, 27 Nov 2023 14:39:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r7ckO-0007wN-NG; Mon, 27 Nov 2023 09:38:04 -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 1r7ckN-0007vu-0T for qemu-devel@nongnu.org; Mon, 27 Nov 2023 09:38:03 -0500 Received: from mail-lf1-x12c.google.com ([2a00:1450:4864:20::12c]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1r7ckL-0001dY-C9 for qemu-devel@nongnu.org; Mon, 27 Nov 2023 09:38:02 -0500 Received: by mail-lf1-x12c.google.com with SMTP id 2adb3069b0e04-50ba73196b1so3286760e87.0 for ; Mon, 27 Nov 2023 06:38:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1701095879; x=1701700679; darn=nongnu.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=JDV7NNWbW7feY0WfjlX/ZuNLxICHisJ+q0zr+V7dXXU=; b=vzAsu/CbsIE/xsotB3VNML7L8p/Po9tDtXVXTuUd/Mxt61Sa7MgnaeoLqDWSs5bGMm U2WzJA8BGu676WuwENwfKz+EUlnYzJSAq4dpFJGwdN5F7kVI9AQwZcs7QJKpgYYUnBpH H5ZxrVnTXlEzqT2TjFqLVydGxJB3J0HTKspaRH3w8/nf2a9+H6SjbkjVMYTakNcBmXl6 tFKeChg11X4N9SeZ+oYIBS9Ay3bpqMVVAQkoRyVnAK3/xHR0o6+huxHS1NE3RTQx0oNA RP2Fm118t+z2+X8dO0U1BIpvAfp9ZO2qEctP2hq8tI+YK/DySZvNgIgUQN85D4rhy1S0 BLBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701095879; x=1701700679; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JDV7NNWbW7feY0WfjlX/ZuNLxICHisJ+q0zr+V7dXXU=; b=xHX3gXFNYKkf++Z1aKAmGxFeJMFBWsD0/WhC9iDCm0mdx9DGwMoBUeOgOshcbycNKK 6Nc/GzIPPA6XI5ZBUQWemcKftt0kx1BCW7rw28GGphlvQhiaAnZtvpterAiNwrKdl+GV 66NcZKQ1mnThL+PCK2hyKcWupnIMeoZI5czx8xc0MBdHqzrR1tMTR/gAN9J+woxV/AAp HhdrF29eBX4P38coE3Xir6lj/yckNLiPl9Xrklnzr045hdwW5wbdpWcVlnPq2RZwX5Hu GqLnc2Ww3U31aJlPPgGODxBtUiWtVFYo1glT+W7bh9ji18MXAR1PDYKzPVoHh25MEgoO Sw+A== X-Gm-Message-State: AOJu0YwT0DPzudstwCwXQdKpxzj5fylSV/Ahf/6BoJ7ysuyhgo8FfhXG ib4D6h+L4uRD5Tj/uy3apB11uKv+WsoyaFmZH02/Kg== X-Google-Smtp-Source: AGHT+IGIB619fZUypFeYYDiBVTqpyVsX3ELzRSXp8GJGbrlBy36lfY3EYY+jOtgzaIz3kcP2UL8VogOOOI3ZI+H28UY= X-Received: by 2002:a05:6512:280c:b0:503:3808:389a with SMTP id cf12-20020a056512280c00b005033808389amr10887334lfb.11.1701095879038; Mon, 27 Nov 2023 06:37:59 -0800 (PST) MIME-Version: 1.0 References: <392b2fb5-1747-0f73-826f-b410cdc84f07@redhat.com> <531d4099-747f-5ab5-8c9c-30c50e6115c8@redhat.com> In-Reply-To: <531d4099-747f-5ab5-8c9c-30c50e6115c8@redhat.com> From: Peter Maydell Date: Mon, 27 Nov 2023 14:37:47 +0000 Message-ID: Subject: Re: hanging process with commit 69562648f9 ("vl: revert behaviour for -display none") To: Sebastian Ott Cc: qemu-devel@nongnu.org, =?UTF-8?B?TWFyYy1BbmRyw6kgTHVyZWF1?= Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::12c; envelope-from=peter.maydell@linaro.org; helo=mail-lf1-x12c.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 Mon, 27 Nov 2023 at 13:08, Sebastian Ott wrote: > > On Mon, 27 Nov 2023, Peter Maydell wrote: > > On Mon, 27 Nov 2023 at 12:29, Sebastian Ott wrote: > >> qemu fails to start a guest using the following command (the process just > >> hangs): qemu-system-aarch64 -machine virt -cpu host -smp 4 -m 8192 > >> -kernel /boot/vmlinuz-6.7.0-rc1 -initrd ~/basic.img -append "root=/dev/ram > >> console=ttyAMA0" -enable-kvm -device virtio-gpu,hostmem=2G -display none > >> > >> ..which I've used to debug a potential virtio-gpu issue. Bisect points to > >> 69562648f9 ("vl: revert behaviour for -display none") > > > > Is it actually hanging, or is the guest starting up fine but > > outputting to a serial port which you haven't directed anywhere? > > Ough, that's indeed the case. I only had a quick glance at the bt in gdb > and obviously misinterpreted what I got there. > > > The commandline is a bit odd because it doesn't set up any of: > > * a serial terminal > > * a graphical window/display > > * network forwarding that would allow ssh into the guest > > > > If you add '-serial stdio' do you see the guest output? > > I do. I was using the serial terminal which got setup implicitly I guess. Yep. The issue fixed by 69562648f9 is that we briefly incorrectly made "-display none" do more than just "disable the display window". The revert brings us back to the normal behaviour that if you want a serial port you need to ask for it. (Or use the -nographic option, which is a legacy 'do what I mean' option that does multiple things at once including turning off the GUI window, and adding a serial terminal and a monitor multiplexed onto stdio. But personally I find it clearer to explicitly ask for all this stuff via '-display none -serial ...' etc.) -- PMM