From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH8PR06CU001.outbound.protection.outlook.com (mail-westus3azon11012058.outbound.protection.outlook.com [40.107.209.58]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD88D202963; Wed, 8 Jul 2026 23:04:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.209.58 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783551879; cv=fail; b=BnUQSISVdmar9YPexXR32fm9xv/s5GQnWzqc7zlSRaW3QX9P1rDNGvU9istsq6llnj1yJMZ7H+pdUx6/CqMX9bWn+bYLSJwMmaErTuYmpzsNLHTF7QOro2lhgRtgtdZp5uYzcE0yfAv2pU+3Br5Q3VI5MFs5NhoSupCThCHCaV8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783551879; c=relaxed/simple; bh=iFeYyQqQ2ESYVJ/Z9qzIlDs5uOXRhXE4SratLAfQr4o=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=MkZa43823Av6HCUHc+Kig3McOZ6DTZCe4TJBymey/ASgco+2phQ/bfdijVHSJHQOOF19TDqYW74bM4ErFVK/AlrvyH23WqZuiSHhrNlcUvyLury97fhXYaJlh4+oc+mQoi5iqSdf7odOlzjkRU5wx/jPUdIz3YB5KSlYIfjvlDk= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=iWbQYYTe; arc=fail smtp.client-ip=40.107.209.58 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="iWbQYYTe" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=DnOa5b245H05vEHhMXJ3ABezFZ//ve9Qu8TfNmfUyFzNATHD6O+IQIfK833OM+GtrBhVfI+7aERLSFssS+E0JBNpnoVsxVtiranplTOPGKpUY6CjDXDZqlrFxq3E0XmKPwAPT6QupuW+zbaige9YY5rpB/MLHHCtXH10cP43H87CCvx3Ngq+PVeeo481Tz7fJzjZvHvMfzltKxLdDTxFFokMus/21FkrchDv2KWNSr/SNczk0mOFJpdWWpD32pfSoViK0cPVfysrjiXdkI4sNfojt7Pg1RZ0sOTT58r+cXNjG7iVTdvVPD94WLSzlyyPS1GKkezDnsXhxRo7YCyg+A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=vQ7rfUlKoTW7CpSwrS03RKUAkuZykq+CVQRCbZrVIMs=; b=mA0b4s0ZhILz8zq8+n9vaGAObk030N+IoSJnibo+DxfBrMsW9pEtNEWndu97HBb+PE9yF1HOIQkF0OwYjCG0G6AJsv9oV52Mnx+RZs+D/zTUonl1zAKu2f9tctUgbWjhI75LhBTHsE2L9bRyOhRjs7DSjTyi1hUcgFFGWl4F6+/Cseb8gJJV1hmlaLOtKRISbPWo2DjYJlGK1GyB4qvn4TiulDR+jCvUdkVObP5siQ6WAtfFiYnhFIfzgUDQOL157i0Yn+ulj3n2X3zz/GVk1qMurlKwDt+LfyyZJ4IfYPigdwq3OilH8dlQ55Y7XjaZQpbFt19Eg04SbNxT5oUztQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=vQ7rfUlKoTW7CpSwrS03RKUAkuZykq+CVQRCbZrVIMs=; b=iWbQYYTeppuzfUwAbBvuNasjaLqwNHeASu3JVg6eZZ+JmgdpXO3bYO2SoVpVhAxrRe3OoEOFXHTlljDniBM2y/KUFHu2WbVa59UztSab+2IkIdQWOsAZnfUxOKq/hy5kEKqyhalgkKJ45pXwQhRtisJ8qrIwHueHwMxDa8wNRVE= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BL1PR12MB5320.namprd12.prod.outlook.com (2603:10b6:208:314::17) by DM4PR12MB5819.namprd12.prod.outlook.com (2603:10b6:8:63::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.181.10; Wed, 8 Jul 2026 23:04:31 +0000 Received: from BL1PR12MB5320.namprd12.prod.outlook.com ([fe80::1876:4a6d:2cf5:b8d1]) by BL1PR12MB5320.namprd12.prod.outlook.com ([fe80::1876:4a6d:2cf5:b8d1%5]) with mapi id 15.21.0181.014; Wed, 8 Jul 2026 23:04:31 +0000 Message-ID: Date: Wed, 8 Jul 2026 18:04:27 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [RESEND PATCH v4 05/15] x86,fs/resctrl: Introduce architecture hooks to program kernel-mode To: Babu Moger , corbet@lwn.net, tony.luck@intel.com, reinette.chatre@intel.com, Dave.Martin@arm.com, james.morse@arm.com, tglx@kernel.org, bp@alien8.de, ben.horgan@arm.com, fenghuay@nvidia.com Cc: skhan@linuxfoundation.org, x86@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com, akpm@linux-foundation.org, rdunlap@infradead.org, peterz@infradead.org, feng.tang@linux.alibaba.com, dapeng1.mi@linux.intel.com, elver@google.com, enelsonmoore@gmail.com, kuba@kernel.org, ebiggers@kernel.org, lirongqing@baidu.com, seanjc@google.com, nikunj@amd.com, xin@zytor.com, pawan.kumar.gupta@linux.intel.com, tiala@microsoft.com, chang.seok.bae@intel.com, kprateek.nayak@amd.com, prathyushi.nangia@amd.com, kim.phillips@amd.com, naveen@kernel.org, darwi@linutronix.de, elena.reshetova@intel.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, thomas.lendacky@amd.com, eranian@google.com, peternewman@google.com, qinyuntan@linux.alibaba.com References: <34a5119a28e102b8d6a0d0cfc3623fb0813a11f7.1783461016.git.babu.moger@amd.com> Content-Language: en-US From: "Moger, Babu" In-Reply-To: <34a5119a28e102b8d6a0d0cfc3623fb0813a11f7.1783461016.git.babu.moger@amd.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SA9PR13CA0074.namprd13.prod.outlook.com (2603:10b6:806:23::19) To BL1PR12MB5320.namprd12.prod.outlook.com (2603:10b6:208:314::17) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL1PR12MB5320:EE_|DM4PR12MB5819:EE_ X-MS-Office365-Filtering-Correlation-Id: 713cc554-0bca-4c0b-8b79-08dedd4544d7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016|23010399003|921020|4143699003|5023799004|11063799006|56012099006|6133799003|22082099003|18002099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BL1PR12MB5320.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016)(23010399003)(921020)(4143699003)(5023799004)(11063799006)(56012099006)(6133799003)(22082099003)(18002099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?R0V4VjBOdzBLWFA1cjhzL2N4dTFBOUZUUzRJUjZ1SlpQM1JSWkEvUk5PRmUy?= =?utf-8?B?aGFxZVRYeWhySitDdE1BRW9QWmpPYjBHbExuU1duNkVuYnlZNlJ0ZWFqVHhC?= =?utf-8?B?QVQrbHpGTTRybTI4eXc0V2J2dnIzdVNZeEpoRDhnTzBab0w4WTRLNTBjVGFQ?= =?utf-8?B?S1NHV3dxRmNsUzlERERxQ1ByRmVUSXhwUGJwL3JieG9WWlRyQjVGR1o3Qnlw?= =?utf-8?B?WXRxV1FIdEU3dklwU3NpNjNPcU9LQUhpV0xDZFZLb1NLK016YVB2bTNtNGxY?= =?utf-8?B?OFBsemkxeG96c0hFcXBuWWQxSmNCc1hkUzh6MTN6VXR0YnhLbTN4Q2xMNUhp?= =?utf-8?B?TWE3NjBiREprYUk1aHdPTG5ENXFlUGcvUDJSVmpmelJVRmprTDFSSGtLSXRK?= =?utf-8?B?SXFkaVRlMzJGRVZBakcyMUhQWGM1VEdTOTFuMGdTMi81RXN2bEpHeDlaVGxi?= =?utf-8?B?NHZBci9KZkdpZ1JpbnB2c3hxdll0OWMrVzF1dUh6L2k4ME4xSnhVWGw1S0d5?= =?utf-8?B?MXFldUFWM205MlI5Z3J2MXVFVWNUN2hlT1lOV2ljRmlTMzF2L3YwMlNnWjFy?= =?utf-8?B?N015OFhhR2MwVHFJSE4rMjc4VHgrMFBRQmZkaGtqcE9ZVlY0LzUvejQyT2Mx?= =?utf-8?B?TjhhNllXU2RLYVgzSmFBV2hwbHh4Q01hWVJ2TENDNTI2ZUJVRlo2MEg3STVx?= =?utf-8?B?VEdHYXhPY2RiQm9QN05QQkFaMDdjbEFCV2FQY3gwWTUrVFBWMU4vc2VTWWVu?= =?utf-8?B?SkpnQXRnOUoreEVlcjlDYVhjc1o0ZCtuL0REeWtLL2VmYTl6WUVLQzNGNkp4?= =?utf-8?B?TXJRTzgwNlRFMzZzdFd5bWk2S01DNW9OZXo1aURVWXczY01ZNW90TnBHOXg4?= =?utf-8?B?Y1dBUDd0NjRQRDRxOXYvcWxxVlBKSXY0QTg1dGttTUNSM3RLZWlNYWdpenZy?= =?utf-8?B?OTJzRjNNc3ZFcG1Dckx0TXRWajVxWjNIRzZ2SVdKcjkyM0JVZUxzQWRIZ1JX?= =?utf-8?B?Z2lKRktZdTRNUDJkM3QveWFyUDIzdXo5S2dQaG1KQ0k1Qmh5NnJleS9WN3BP?= =?utf-8?B?RVlmZkxvcmhsaTlvNXhTKzlMSUU3TmxabXNCOGpLajVsNDlsbUtpb2NxUTNj?= =?utf-8?B?YmF1d2E4MUhxYVorcFl4ajF3OE0wbDdhZ0t0eEZEWW93Wjd1UjhFdWhraG54?= =?utf-8?B?a1pMdE5HemJBTGNsMEdhUHpRVzRxWm9XNjl3SWtDSURkbGxsSTJQMGVsaWU2?= =?utf-8?B?NzBKRDBiRFdLT3JMWllOd2Z4SW1Xc0daVytwaFl1RWFHM0Fkc25SS25CWXBp?= =?utf-8?B?cnlhaHBlRkZkSzArdWdqaGQrOWo5dVNRQjgwUnBYYUsvNEFBOVJaRkl1bnJX?= =?utf-8?B?WjMzT1MvYTcxaGxwcEJ0N1haNGxsQWRVdC95M0dKNWVBdUczQ0t4djBhaDgv?= =?utf-8?B?clVoN0Vvd0Vnd1BMd0NEdmNITnBUVmEybll3T2NibHA5VXRJNmZrZ1YvRDNp?= =?utf-8?B?K295U3F5M2tjd1NjZ3RrT011NnVjUGtiYnhWck8vcGdzYk1NTHJDNHlaWFVH?= =?utf-8?B?QnZDNU1sVlZyYzlUc2ptUitHSFFub1kvNVdrS2VtZnMyL0pWZ1lXaVEzSWNi?= =?utf-8?B?dE1paHBwdkFkeEZsc25ycjF3TUpnUjdLbTVWb2IvVTFBQ1lWN05UaGJjWkdC?= =?utf-8?B?c2lJYTUyc3poa254WWdyZ3Y1QWxaclFHQmFxOHY0UmR2NzUrWm5TRllsRFJU?= =?utf-8?B?eWo4YTlMakpRY1F1dkZ6K0ZkUmp1SnRjWTNPRTQyTHRFcVRycDBZZEtsN3RQ?= =?utf-8?B?NlVnWVJPeVpoUS8yZnBNblh4MHBPbEt1U3lFTEZCY21DRzFWUnA0cEZHakdH?= =?utf-8?B?SW8vTERlN0VLckFpYnk3TStEU1NFT24rSk92Z29McWtWR0RUVlpkdURuMnZR?= =?utf-8?B?cmtnak1KWmZqamk4OGVKcTlrYnNZeVlJYlFKWW5XbUdYRDJRRTl0cG5Ya0xY?= =?utf-8?B?djdPVmxVekZaaDgwRmdlUDg4c1hsMVg2bFhwYTFXYXgvY2s2R1lCOFRvaGdW?= =?utf-8?B?QXJXYVNpNld1QmJlV1VKcElMSGZlM25oTmtNNTNmUm1VRXBOQUZJQVVLUXFQ?= =?utf-8?B?bU5oNTJoMnhjTHFBNThUSDNhbnFkenZWMUFZNmVhRzBsYnFDd05FVUFFekhi?= =?utf-8?B?S3FWa243R1JQa3dSQmZncDloc1Q1ZW1Bdi92SFpuUldtSXdmTmkvWnVJYUJr?= =?utf-8?B?b21zVXVMNUxiZDAxVS9MUGptRjA0UC9ERm5EemdnbUpDcGdkQ3czVXVHOEdS?= =?utf-8?Q?u3aeX147N/Bkq2gLIv?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 713cc554-0bca-4c0b-8b79-08dedd4544d7 X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5320.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2026 23:04:31.2497 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: STas7dXefMIUnvXIncOfHeboK00nxCMCfqNmTuaooUCH97wv8r71nfTQOYUA4b62 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB5819 On 7/7/2026 4:50 PM, Babu Moger wrote: > Kernel-mode policies defined by enum resctrl_kernel_mode must be applied to > each affected CPU whenever a policy is selected or its scope changes. > Generic resctrl therefore requires an architecture-specific interface to > program allocation and monitoring associations in hardware across a given > CPU mask. > > Introduce a helper, resctrl_arch_configure_kmode(), to handle kernel-mode > programming. On x86/AMD systems, this helper programs the > MSR_IA32_PQR_PLZA_ASSOC register on all online CPUs in the specified mask > via on_each_cpu_mask(). Also provide a no-op stub for MPAM systems. > > Generic resctrl does not invoke this hook yet; it will be used when user > space selects a kernel-mode policy or updates the associated CPU set. > > Signed-off-by: Babu Moger > --- > v4: Added assign_mon parameter in resctrl_arch_configure_kmode() to program the RMID > as discussed in below. > https://lore.kernel.org/lkml/20260605100642.1103628-1-qinyuntan@linux.alibaba.com/ > Changed cpumask type to "const struct cpumask *cpu_mask". > Added MPAM stub to avoid any linking issues when resctrl_arch_configure_kmode() > is called from FS layer. Thanks to Qinyun. > Re-wrote the changelog to be generic. > Updated code comments. > > v3: Removed task based PLZA implementation so related changes are removed. > Removed handling of rmid_en as it is not required. The group type assigned > will be different so the monitoring part is already taken care. > Updated the change log with details. > Removed resctrl_arch_set_kmode() as arch only provides the modes supported. > It is FS which decided which mode to apply. > > v2: Updated the commit message to include the sequence of steps to enable PLZA. > Added mode code comments for clarity. > Added kmode to functin names to be generic. > --- > arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 36 +++++++++++++++++++++++ > drivers/resctrl/mpam_resctrl.c | 5 ++++ > include/linux/resctrl.h | 15 ++++++++++ > 3 files changed, 56 insertions(+) > > diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > index b20e705606b8..025f139434f2 100644 > --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > @@ -131,3 +131,39 @@ int resctrl_arch_io_alloc_enable(struct rdt_resource *r, bool enable) > > return 0; > } > + > +static void resctrl_kmode_set_one_amd(void *arg) > +{ > + union msr_pqr_plza_assoc *plza = arg; > + > + wrmsrq(MSR_IA32_PQR_PLZA_ASSOC, plza->full); > +} > + Sashiko reported: https://sashiko.dev/#/patchset/cover.1783461016.git.babu.moger%40amd.com?part=5 --- Patch [5]: [RESEND PATCH v4 05/15] x86,fs/resctrl: Introduce architecture hooks to program kernel-mode --- commit 97958c0d99b7e538d1f8d019e6c63712b44a6289 Author: Babu Moger x86,fs/resctrl: Introduce architecture hooks to program kernel-mode Kernel-mode policies defined by enum resctrl_kernel_mode must be applied to each affected CPU whenever a policy is selected or its scope changes. Generic resctrl therefore requires an architecture-specific interface to program allocation and monitoring associations in hardware across a given CPU mask. This patch introduces resctrl_arch_configure_kmode() to handle this. > diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c [ ... ] > +static void resctrl_kmode_set_one_amd(void *arg) > +{ > + union msr_pqr_plza_assoc *plza = arg; > + > + wrmsrq(MSR_IA32_PQR_PLZA_ASSOC, plza->full); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Will this truncate the upper 32 bits of the MSR on 32-bit x86 builds? It appears that union msr_pqr_plza_assoc in arch/x86/kernel/cpu/resctrl/internal.h uses unsigned long for both the bitfields and the full variable. On 32-bit x86 architectures, unsigned long is 32 bits, which means reading plza->full will truncate the 64-bit value. When this is implicitly zero-extended to u64 and passed to wrmsrq(), the upper 32 bits of the MSR, which contain plza_en, closid_en, and closid, will be overwritten with zeros. Will change the union msr_pqr_plza_assoc to use u64 instead on unsigned long. It should take care of this. Thanks Babu