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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B490BC4338F for ; Mon, 23 Aug 2021 12:31:07 +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 5CEFC6137D for ; Mon, 23 Aug 2021 12:31:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5CEFC6137D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:33046 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mI96Y-0007a9-8o for qemu-devel@archiver.kernel.org; Mon, 23 Aug 2021 08:31:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45924) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mI93p-0004oG-RE for qemu-devel@nongnu.org; Mon, 23 Aug 2021 08:28:17 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:3118) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mI93m-0004t3-Tt for qemu-devel@nongnu.org; Mon, 23 Aug 2021 08:28:17 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GtWd00CJYz8tQW; Mon, 23 Aug 2021 20:24:04 +0800 (CST) Received: from dggpemm500023.china.huawei.com (7.185.36.83) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 23 Aug 2021 20:28:11 +0800 Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.187.128) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 23 Aug 2021 20:28:10 +0800 From: Yanan Wang To: Subject: [PATCH v7 01/15] machine: Deprecate "parameter=0" SMP configurations Date: Mon, 23 Aug 2021 20:27:50 +0800 Message-ID: <20210823122804.7692-2-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20210823122804.7692-1-wangyanan55@huawei.com> References: <20210823122804.7692-1-wangyanan55@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.174.187.128] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500023.china.huawei.com (7.185.36.83) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.188; envelope-from=wangyanan55@huawei.com; helo=szxga02-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-0.001, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Andrew Jones , Cornelia Huck , =?UTF-8?q?Daniel=20P=20=2E=20Berrang=C3=A9?= , Eduardo Habkost , Pierre Morel , "Michael S . Tsirkin" , Pankaj Gupta , Richard Henderson , Greg Kurz , Halil Pasic , wanghaibin.wang@huawei.com, Thomas Huth , Paolo Bonzini , Yanan Wang , David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" In the SMP configuration, we should either provide a topology parameter with a reasonable value (greater than zero) or just omit it and QEMU will compute the missing value. The users shouldn't provide a configuration with any parameter of it specified as zero (e.g. -smp 8,sockets=0) which could possibly cause unexpected results in the -smp parsing. So we deprecate this kind of configurations since 6.2 by adding the explicit sanity check. Signed-off-by: Yanan Wang Reviewed-by: Cornelia Huck --- docs/about/deprecated.rst | 15 +++++++++++++++ hw/core/machine.c | 14 ++++++++++++++ qapi/machine.json | 2 +- qemu-options.hx | 12 +++++++----- 4 files changed, 37 insertions(+), 6 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 8d4fd384a5..ae49e9fdba 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -138,6 +138,21 @@ an underscore between "window" and "close"). The ``-no-quit`` is a synonym for ``-display ...,window-close=off`` which should be used instead. +``-smp`` ("parameter=0" SMP configurations) (since 6.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Specified CPU topology parameters must be greater than zero. + +In the SMP configuration, users should either provide a CPU topology +parameter with a reasonable value (greater than zero) or just omit it +and QEMU will compute the missing value. + +However, historically it was implicitly allowed for users to provide +a parameter with zero value, which is meaningless and could also possibly +cause unexpected results in the -smp parsing. So support for this kind of +configurations (e.g. -smp 8,sockets=0) is deprecated since 6.2 and will +be removed in the near future, users have to ensure that all the topology +members described with -smp are greater than zero. QEMU Machine Protocol (QMP) commands ------------------------------------ diff --git a/hw/core/machine.c b/hw/core/machine.c index 54e040587d..3b5df9b002 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -832,6 +832,20 @@ static void machine_set_smp(Object *obj, Visitor *v, const char *name, return; } + /* + * Specified CPU topology parameters must be greater than zero, + * explicit configuration like "cpus=0" is not allowed. + */ + if ((config->has_cpus && config->cpus == 0) || + (config->has_sockets && config->sockets == 0) || + (config->has_dies && config->dies == 0) || + (config->has_cores && config->cores == 0) || + (config->has_threads && config->threads == 0) || + (config->has_maxcpus && config->maxcpus == 0)) { + warn_report("Invalid CPU topology deprecated: " + "CPU topology parameters must be greater than zero"); + } + mc->smp_parse(ms, config, errp); if (*errp) { goto out_free; diff --git a/qapi/machine.json b/qapi/machine.json index 157712f006..10a97837d3 100644 --- a/qapi/machine.json +++ b/qapi/machine.json @@ -1297,7 +1297,7 @@ # # @dies: number of dies per socket in the CPU topology # -# @cores: number of cores per thread in the CPU topology +# @cores: number of cores per die in the CPU topology # # @threads: number of threads per core in the CPU topology # diff --git a/qemu-options.hx b/qemu-options.hx index 83aa59a920..aee622f577 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -227,11 +227,13 @@ SRST of computing the CPU maximum count. Either the initial CPU count, or at least one of the topology parameters - must be specified. Values for any omitted parameters will be computed - from those which are given. Historically preference was given to the - coarsest topology parameters when computing missing values (ie sockets - preferred over cores, which were preferred over threads), however, this - behaviour is considered liable to change. + must be specified. The specified parameters must be greater than zero, + explicit configuration like "cpus=0" is not allowed. Values for any + omitted parameters will be computed from those which are given. + Historically preference was given to the coarsest topology parameters + when computing missing values (ie sockets preferred over cores, which + were preferred over threads), however, this behaviour is considered + liable to change. ERST DEF("numa", HAS_ARG, QEMU_OPTION_numa, -- 2.19.1