From patchwork Wed Sep 29 02:58:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "wangyanan (Y)" X-Patchwork-Id: 1534184 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4HK1NT050dz9svs for ; Wed, 29 Sep 2021 13:01:13 +1000 (AEST) Received: from localhost ([::1]:46646 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mVPqI-0006mN-Ix for incoming@patchwork.ozlabs.org; Tue, 28 Sep 2021 23:01:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60674) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVPnw-0004z2-8D; Tue, 28 Sep 2021 22:58:44 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:2815) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVPns-0005mU-VS; Tue, 28 Sep 2021 22:58:44 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4HK1DP459SzRbq6; Wed, 29 Sep 2021 10:54:13 +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 15.1.2308.8; Wed, 29 Sep 2021 10:58:30 +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 15.1.2308.8; Wed, 29 Sep 2021 10:58:29 +0800 From: Yanan Wang To: Eduardo Habkost , Paolo Bonzini , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , Andrew Jones , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , "Markus Armbruster" Subject: [PATCH v12 02/16] machine: Deprecate "parameter=0" SMP configurations Date: Wed, 29 Sep 2021 10:58:02 +0800 Message-ID: <20210929025816.21076-3-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20210929025816.21076-1-wangyanan55@huawei.com> References: <20210929025816.21076-1-wangyanan55@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.128] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) 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 , Pierre Morel , Pankaj Gupta , Cornelia Huck , qemu-devel@nongnu.org, Yanan Wang , qemu-s390x@nongnu.org, qemu-arm@nongnu.org, "Michael S . Tsirkin" , wanghaibin.wang@huawei.com, qemu-ppc@nongnu.org, David Gibson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.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 Reviewed-by: Daniel P. Berrangé --- docs/about/deprecated.rst | 15 +++++++++++++++ hw/core/machine.c | 14 ++++++++++++++ qemu-options.hx | 12 +++++++----- 3 files changed, 36 insertions(+), 5 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 3c2be84d80..97415dbecd 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -160,6 +160,21 @@ Use ``-display sdl`` instead. Use ``-display curses`` 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. Plugin argument passing through ``arg=`` (since 6.1) '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' diff --git a/hw/core/machine.c b/hw/core/machine.c index 067f42b528..4e409261c9 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -835,6 +835,20 @@ 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("Deprecated CPU topology (considered invalid): " + "CPU topology parameters must be greater than zero"); + } + mc->smp_parse(ms, config, errp); if (*errp) { goto out_free; diff --git a/qemu-options.hx b/qemu-options.hx index 8f603cc7e6..91d859aa29 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,