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 2C67AC54798 for ; Tue, 27 Feb 2024 10:52:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rev40-0007Ox-Gk; Tue, 27 Feb 2024 05:51:56 -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 1rev3x-0007Nj-QL; Tue, 27 Feb 2024 05:51:53 -0500 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rev3v-0002n3-EP; Tue, 27 Feb 2024 05:51:53 -0500 Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4TkZ1V5Kwjz6J9xv; Tue, 27 Feb 2024 18:47:10 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 0695A140F4E; Tue, 27 Feb 2024 18:51:47 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Tue, 27 Feb 2024 10:51:46 +0000 Date: Tue, 27 Feb 2024 10:51:45 +0000 To: Zhao Liu CC: "Daniel P . =?UTF-8?Q?Berrang=EF=BF=BD?=" , "Eduardo Habkost" , Marcel Apfelbaum , Philippe =?UTF-8?Q?Mathieu-Daud=EF=BF=BD?= , Yanan Wang , "Michael S . Tsirkin" , Paolo Bonzini , "Richard Henderson" , Eric Blake , Markus Armbruster , Marcelo Tosatti , Alex =?UTF-8?Q?Benn=EF=BF=BDe?= , Peter Maydell , "Sia Jee Heng" , , , , , "Zhenyu Wang" , Dapeng Mi , Yongwei Ma , Zhao Liu Subject: Re: [RFC 4/8] hw/core: Add cache topology options in -smp Message-ID: <20240227105145.0000106d@Huawei.com> In-Reply-To: References: <20240220092504.726064-1-zhao1.liu@linux.intel.com> <20240220092504.726064-5-zhao1.liu@linux.intel.com> <20240226153947.00006fd6@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500002.china.huawei.com (7.191.160.78) To lhrpeml500005.china.huawei.com (7.191.163.240) Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Reply-to: Jonathan Cameron From: Jonathan Cameron via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, 27 Feb 2024 17:20:25 +0800 Zhao Liu wrote: > Hi Jonathan, > > > Hi Zhao Liu > > > > I like the scheme. Strikes a good balance between complexity of description > > and systems that actually exist. Sure there are systems with more cache > > levels etc but they are rare and support can be easily added later > > if people want to model them. > > Thanks for your support! > > [snip] > > > > +static int smp_cache_string_to_topology(MachineState *ms, > > > > Not a good name for a function that does rather more than that. > > What about "smp_cache_get_valid_topology()"? Looking again, could we return the CPUTopoLevel? I think returning CPU_TOPO_LEVEL_INVALID will replace -1/0 returns and this can just be smp_cache_string_to_topology() as you have it in this version. The check on the return value becomes a little more more complex and I think you want to squash CPU_TOPO_LEVEL_MAX down so we only have one invalid value to check at callers.. E.g. static CPUTopoLevel smp_cache_string_to_topolgy(MachineState *ms, char *top_str, Error **errp) { CPUTopoLevel topo = string_to_cpu_topo(topo_str); if (topo == CPU_TOPO_LEVEL_MAX || topo == CPU_TOP?O_LEVEL_INVALID) { return CPU_TOPO_LEVEL_INVALID; } if (!machine_check_topo_support(ms, topo) { error_setg(errp, "Invalid cache topology level: %s. " "The cache topology should match the CPU topology level", //Break string like this to make it as grep-able as possible! topo_str); return CPU_TOPO_LEVEL_INVALID; } return topo; } The checks then become != CPU_TOPO_LEVEL_INVALID at each callsite. Jonathan