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 4ADE1C47258 for ; Wed, 31 Jan 2024 15:57:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rVCx5-0006E7-2L; Wed, 31 Jan 2024 10:56:39 -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 1rVCwu-00068p-1s; Wed, 31 Jan 2024 10:56:29 -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 1rVCwr-0008Tk-He; Wed, 31 Jan 2024 10:56:27 -0500 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4TQ64v0Yf9z6JB0F; Wed, 31 Jan 2024 23:53:03 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 27C1D1408FF; Wed, 31 Jan 2024 23:56:23 +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_128_GCM_SHA256) id 15.1.2507.35; Wed, 31 Jan 2024 15:56:22 +0000 Date: Wed, 31 Jan 2024 15:56:21 +0000 To: JeeHeng Sia CC: "qemu-devel@nongnu.org" , "qemu-arm@nongnu.org" , "qemu-riscv@nongnu.org" , "mst@redhat.com" , "imammedo@redhat.com" , "anisinha@redhat.com" , "shannon.zhaosl@gmail.com" , "peter.maydell@linaro.org" , "sunilvl@ventanamicro.com" , "palmer@dabbelt.com" , "alistair.francis@wdc.com" , "bin.meng@windriver.com" , "liwei1518@gmail.com" , "dbarboza@ventanamicro.com" , "zhiwei_liu@linux.alibaba.com" Subject: Re: [RFC v1 3/3] hw/arm/virt-acpi-build.c: Enable CPU cache topology Message-ID: <20240131155621.000015d1@Huawei.com> In-Reply-To: References: <20240129081423.116615-1-jeeheng.sia@starfivetech.com> <20240129081423.116615-4-jeeheng.sia@starfivetech.com> <20240129110823.000076df@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: lhrpeml100002.china.huawei.com (7.191.160.241) 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_H5=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, 30 Jan 2024 05:03:15 +0000 JeeHeng Sia wrote: > > -----Original Message----- > > From: Jonathan Cameron > > Sent: Monday, January 29, 2024 7:08 PM > > To: JeeHeng Sia > > Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; qemu-riscv@nongnu.org; mst@redhat.com; imammedo@redhat.com; > > anisinha@redhat.com; shannon.zhaosl@gmail.com; peter.maydell@linaro.org; sunilvl@ventanamicro.com; palmer@dabbelt.com; > > alistair.francis@wdc.com; bin.meng@windriver.com; liwei1518@gmail.com; dbarboza@ventanamicro.com; > > zhiwei_liu@linux.alibaba.com > > Subject: Re: [RFC v1 3/3] hw/arm/virt-acpi-build.c: Enable CPU cache topology > > > > On Mon, 29 Jan 2024 00:14:23 -0800 > > Sia Jee Heng wrote: > > > > > Introduced a 3-layer cache for the ARM virtual machine. > > > > > > Signed-off-by: Sia Jee Heng > > > > There are a bunch of CPU registers that also need updating to reflect the > > described cache. > > https://lore.kernel.org/qemu-devel/20230808115713.2613-3-Jonathan.Cameron@huawei.com/ > > It's called HACK for a reason ;) > > But there is some discussion about this issue in the thread. > > > > The l1 etc also needs to reflect the CPU model. This stuff needs to match. > > Wrong information being passed to a VM is probably worse than no information. > > > > Whilst I plan to circle back to the MPAM support (perhaps next month) there > > is a lot more to be done here before we have useful cache descriptions for > > guests. > Thanks for the info. I will spend time to look into. > > > > Jonathan > > > > > --- > > > hw/arm/virt-acpi-build.c | 44 +++++++++++++++++++++++++++++++++++++++- > > > 1 file changed, 43 insertions(+), 1 deletion(-) > > > > > > diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c > > > index 17aeec7a6f..c57067cd63 100644 > > > --- a/hw/arm/virt-acpi-build.c > > > +++ b/hw/arm/virt-acpi-build.c > > > @@ -426,6 +426,48 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms) > > > g_array_free(its_idmaps, true); > > > } > > > > > > +static void pptt_setup(GArray *table_data, BIOSLinker *linker, MachineState *ms, > > > + const char *oem_id, const char *oem_table_id) > > > +{ > > > + CPUCaches default_cache_info = { > > > + .l1d_cache = &(CPUCacheInfo) { > > > + .type = DATA_CACHE, > > > + .size = 64 * KiB, > > > + .line_size = 64, > > > + .associativity = 4, > > > + .sets = 256, > > > + .attributes = 0x02, > > > + }, > > > + .l1i_cache = &(CPUCacheInfo) { > > > + .type = INSTRUCTION_CACHE, > > > + .size = 64 * KiB, > > > + .line_size = 64, > > > + .associativity = 4, > > > + .sets = 256, > > > + .attributes = 0x04, > > > > This is the duplication I commented on in patch 1. > > The bit set there is the one to indicate it's an instruction > > cache and we have type doing that as well. > But this gives a great readability, no? Not really no. If .type and attributes end up out of agreement with each other it will be non obvious. You could do .attributes { .type = INSTRUCTION_CACHE, .other things ... } if you want to list the type clearly and still maintain the info that this ends up in attributes. > > > > > > > + }, > > > + .l2_cache = &(CPUCacheInfo) { > > > + .type = UNIFIED_CACHE, > > > + .size = 2048 * KiB, > > > + .line_size = 64, > > > + .associativity = 8, > > > + .sets = 4096, > > > + .attributes = 0x0a, > > > + }, > > > + .l3_cache = &(CPUCacheInfo) { > > > + .type = UNIFIED_CACHE, > > > + .size = 4096 * KiB, > > > + .line_size = 64, > > > + .associativity = 8, > > > + .sets = 8192, > > > + .attributes = 0x0a, > > > + }, > > > + }; > > > + > > > + build_pptt(table_data, linker, ms, oem_id, oem_table_id, > > > + &default_cache_info); > > > +} > > > + > > > /* > > > * Serial Port Console Redirection Table (SPCR) > > > * Rev: 1.07 > > > @@ -912,7 +954,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables) > > > > > > if (!vmc->no_cpu_topology) { > > > acpi_add_table(table_offsets, tables_blob); > > > - build_pptt(tables_blob, tables->linker, ms, > > > + pptt_setup(tables_blob, tables->linker, ms, > > > vms->oem_id, vms->oem_table_id); > > > } > > > >