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 5EB09C3DA7F for ; Mon, 29 Jul 2024 08:59:55 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sYMDV-0006PO-VB; Mon, 29 Jul 2024 04:58:53 -0400 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 1sYMDU-0006Oa-BB for qemu-devel@nongnu.org; Mon, 29 Jul 2024 04:58:52 -0400 Received: from mail-ej1-x62a.google.com ([2a00:1450:4864:20::62a]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sYMDS-0004hw-MW for qemu-devel@nongnu.org; Mon, 29 Jul 2024 04:58:52 -0400 Received: by mail-ej1-x62a.google.com with SMTP id a640c23a62f3a-a7a9e25008aso419201666b.0 for ; Mon, 29 Jul 2024 01:58:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1722243528; x=1722848328; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:from:to:cc:subject:date:message-id :reply-to; bh=HRMii+RlBXa8/ciEPBTTq/5S+gWxNao+gfER2Vs4a5Q=; b=LpZgFGIIQGUROXO3DJSoVtuhrjVPnvM82pita6TfrqgCoH5SFZQOBrOTunS4qco8TF PQ28UJYyE62ogmSV48uNW5jAfdXB5E34FSj94QrYz8h8v9Aa5KGg7uDyNhth8Vz3F27b gTJKp5XF+jftXIgHbgTVzC/AUGEoo1wIp9gHs1PfSLAtRNvqU6NbV624uYuG8JvpYved xnjzy8yl6g62s8dX5fNn9GQG37W52ICocDmgwoPbZ6zeAZZbtsN7eqXfaGUWcexko4WR HLbpuRcDtpvXl+un12j4bzpnvvXb6IA16IJMzqEuEiwjhzsYvP1G7PWlo9unBcJljfP2 1FvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722243528; x=1722848328; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=HRMii+RlBXa8/ciEPBTTq/5S+gWxNao+gfER2Vs4a5Q=; b=ESZWER47UPTqLgYSu/BF2PQauVyYMEUPIxJAE4XQUgHXW7dYwqlD8/1mLFh9XvwVK9 FfVgD/RaRqC81reuY9mdpLmX7ylfSIMPcQ0g350yG0tbuJY62ocOCPzQoMmIviSELJwp GkKKAd67WaEa/97zCVqmQ57LXw2gQ7Xi2J81Q5zfTvNvzjNW4TDOXpEcCe+jTgtTrOuu sj+eeHhQfyPwMYmg6VSRL4lRC4LoSA5f6SRmZO/It2rvj+X4dgm9j0w+7IKMJqAUFWJQ c5+epm6r/huLSfkT1L1rx8I+2plLRLaU+yOGR+SARpiDrVnc/x3P5ODM3T1mNa0uNxxU Dpmg== X-Gm-Message-State: AOJu0YwuKIp/WeVSGF3ig7720AwBmHCQ7lyoXdhrxp+y7IqLqjOiieBf Bh1x0GN/VFg5/Ng1G6k6I8IVSUZGDPJ5TPmbiJohz9CYE26SqAe+jmQNRR7AT6k= X-Google-Smtp-Source: AGHT+IGvRmnQNZpMTFSaeTSwfi+Xtl0d0yqcwpvdYMXQ4pPV/QZOT6slESrrJG/ycVcq6xVNEj8FtQ== X-Received: by 2002:a17:907:97cd:b0:a7a:929f:c0ce with SMTP id a640c23a62f3a-a7d40044af9mr512797966b.19.1722243527270; Mon, 29 Jul 2024 01:58:47 -0700 (PDT) Received: from draig.lan ([85.9.250.243]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7acad91eeesm485207866b.178.2024.07.29.01.58.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jul 2024 01:58:46 -0700 (PDT) Received: from draig (localhost [IPv6:::1]) by draig.lan (Postfix) with ESMTP id B2C595F844; Mon, 29 Jul 2024 09:58:45 +0100 (BST) From: =?utf-8?Q?Alex_Benn=C3=A9e?= To: Sergei Lyubski Cc: qemu-devel@nongnu.org Subject: Re: The question about migration/checkpointing In-Reply-To: (Sergei Lyubski's message of "Fri, 26 Jul 2024 12:41:47 -0700") References: Date: Mon, 29 Jul 2024 09:58:45 +0100 Message-ID: <877cd41smy.fsf@draig.linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::62a; envelope-from=alex.bennee@linaro.org; helo=mail-ej1-x62a.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 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 Sergei Lyubski writes: > Hi guys, > > My name is Sergey. My company uses QEMU for CPU performance simulation/e= valuaton. > Sorry, I found your emails in QEMU relatively recent commits into ram.= c . Why ram.c . Because I see some weirdness in > the behavior. >=20=20=20 > Our goal is : > a) To boot Linux , to launch some TEST/SPEC, to drop a few checkp= oints. > b) To resume execution from those checkpoints, to attach a perfor= mance simulator and > to evaluate performance at the "hot" code areas. > > How we tried to do it . > > a) run QEMU with -monitor telnet options > b) connect to QEMU with telnet=20 > c) after LINUX booted in QEMU monitor (telnet) executed > migrate -d file://=20 > quit > d) run QEMU with option -incoming file:// > > Now !! > > If I drop the checkpoint when running on linux a long ( endless) te= st which prints on the console, everything works (!) > and the console is properly restored. >=20=20=20=20 > When I drop the checkpoint when the linux console is in shell prompt= , the restoration does not work. > I see either error message from ram_load_precopy() > error_report("Unknown combination of migration flags: 0x%x", > flags); I suspect seeing the value of flags will help with any diagnosis. > > or > > the console is locked, QEMU restarts and runs (ps, top). The only = solution is to kill=20 > QEMU . After that, QEMU console is distorted and requires to type > RESET. Are you able to attach with gdb and get a backtrace? > > Could you please comment on the above issues.=20 > If you need more info I can send you my screen shots. > Please note that that the similar behavior is observed on both > qemu 9.0 ( stable-9.0) and > qemu 8.x > > Thanks in advance. > Sergey Lyubskiy --=20 Alex Benn=C3=A9e Virtualisation Tech Lead @ Linaro