From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH0PR06CU001.outbound.protection.outlook.com (mail-westus3azon11011050.outbound.protection.outlook.com [40.107.208.50]) (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 0BDCF30DEA3; Tue, 13 Oct 2026 01:00:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.208.50 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791853242; cv=fail; b=JZayloLJZOkgoYBLkbbzGx3R558A8wdUcH0QFOqZ7d14AyXepQJyuFuP6btv+PWbdv9HdWvFyCYvnxNk8jpq1WZFGcbIhKhgh0EJMQUnEO+78rUwF3KsxxXcCOpjGP/X1HL+/9U/XxpapMKckey0szzTC71xZHhUA7wI9kZTSuU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791853242; c=relaxed/simple; bh=K3o59doHMBlrB4DIESLSCNIEwVUKsBcNVzptHIfIKAg=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=rqjbGnrMSiXjU6IBXuppxfsqNBIQa87yvcZ4J7Fag0POpOlKbFYlMk4zSdwoIqRP4jI+9pbfRJ+WmaGoKXv24KwMdYr01QVwUn4TKjO/c3eawmNwGk2ST004Xv474390IvFBlo9q3n27IOZyp9J4G73C/Zt5szk7t/AHK2QRD5M= 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=FQKMutnK; arc=fail smtp.client-ip=40.107.208.50 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="FQKMutnK" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Bk4QvEYlBWJoX38ZE6sY5Ee8HPzQRkV4q/fMekiS9ODPB6fkTCxF4V15gHh4pwlWVY0JJb+c06hWnWIDdxcJE8uPxIlSh7zPswcJ1RwUJgoRBo4vu3Bn+tpmiJ5b4FVBuYAWPOtO8Y1kS05meTraVKNeju/rjbyOgC2/n8Riec43hAKF5VqRGuxe5BDcjiifY5yHvwPwcTQzbnP8HvD3Ti74knyl4jY+Uf83QsX5RMgUr01ijRFfs3oyJwdNzuHiSerme3KlJWZN4686kmu7nvzU0MOAf6xrf5bPLtq291TscCkZj1YZC5yBCmES5uDZMVWEzCqRNOGf+/prHKDvFg== 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=zGxKphlnlw6MLGnSHARDn2gFdQmqhl+FNzycaWnqirg=; b=d8d0527UH6m1dIO2x1gJyGBZ0YYMZVtjHU0RZp+2EtJaxF16ZDriEI1W2lX5auAmh7hUKcCWgQWixzjjd9vo7wLg37+WM8UM5DbyBKSFuZ8w4AZdcdoqMygAzt0JfnUvqYAcorrn222DaMTm6EzrD3GXUWfmECX1/a+PhajML6Uh2fl9OtIxnxbB554OYXRScbLdL+7n+zfVWPNqst1552VRkIAB8vP+JzBzFZTe7ZsjbIWjNc2cwkDCFW2vQrzZbUMCvUOEbgBFoZ9dwi/scNeURp+tZWL/Sk3GdvHjCtS3g+l/J4pWpYItydTnGQpI6PfD3g5ZS/+dkRQJIrw53Q== 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=zGxKphlnlw6MLGnSHARDn2gFdQmqhl+FNzycaWnqirg=; b=FQKMutnK6e8gKbLPC5uZCKIyf35NMnm+U1wJ/oGR8knQDFQ6wruaJKgWLob+6dJxNbk5dM8i0Ii6r4h56tSNolO5C4ng2pBOd/ochiEwskuViAMck/OykRy8z+XOZXH3YxnrI4Knxv5+ydvbIeQQM2aVMtpNha5xyntvugsFyIQ= Authentication-Results: mx.microsoft.com 1; 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 SJ5PPFEB07C8E34.namprd12.prod.outlook.com (2603:10b6:a0f:fc02::9a8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.496.23; Tue, 13 Oct 2026 01:00:37 +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 15.21.0496.015; Tue, 13 Oct 2026 01:00:36 +0000 Message-ID: <2d56a760-de60-4a5b-a270-b504ff2ca345@amd.com> Date: Mon, 12 Oct 2026 20:00:32 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/3] x86/resctrl: Fix ABMC counter programming To: Reinette Chatre , Babu Moger , tony.luck@intel.com, bp@alien8.de Cc: x86@kernel.org, Dave.Martin@arm.com, james.morse@arm.com, corbet@lwn.net, skhan@linuxfoundation.org, rdunlap@infradead.org, tglx@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com, kas@kernel.org, rick.p.edgecombe@intel.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org References: <94c453ca762ef0c32680ac1163099c30866a99c0.1791589412.git.babu.moger@amd.com> <0ce0ac49-d0aa-42c5-b0a3-08b09b9f130b@intel.com> Content-Language: en-US From: "Moger, Babu" In-Reply-To: <0ce0ac49-d0aa-42c5-b0a3-08b09b9f130b@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SN7PR04CA0094.namprd04.prod.outlook.com (2603:10b6:806:122::9) To BL1PR12MB5320.namprd12.prod.outlook.com (2603:10b6:208:314::17) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL1PR12MB5320:EE_|SJ5PPFEB07C8E34:EE_ X-MS-Office365-Filtering-Correlation-Id: 2db3521f-fb73-4751-0131-08df28c563ee X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|23010399003|366016|376014|7416014|10067099003|3023799007|261009223027099003|11063799006|4143699003|6133799003|22082099003|18002099003|56012099006; X-Microsoft-Antispam-Message-Info: q3n/j2TU7qPi5pWNVvBPllsAc8XHAy8oDGpclNXf/w52tEO0KqCgLJ6LP14H6DgPC92tFDKGpfpiq0sAQ3FiNE3Ugvx2BWOqFCZPjNcDfub1rkWJzTp/vuVcj5A7rEkqFTc6s3Z+xdn/pwHvd2GJ0oErwKSfoLOLV0MGweL8nDf/nzdPXaSSkkYaaXFOoe91c7Ed6+o5dtbj7R24mckpPot2Z8ec5UkKwww+NiTOCj+7z4vu61XCQsnJDYYt31Pt2gYtEVJgPidW8SkYR/95OdQJa6WT2lZex5zfecJlp4lT2UolSLOpPu4tX5ohNDFkGmv0rIiw34zuq69p05DtdGwda7+KAkCAH6RlKSbXfOBMtG7m4TSO79huncMjfzByooOoDJcUCGVK6AqoJKQa1IrtJjP1MnffxS+lLs7u04pbTgQEbETTTGEQf07OH7J1lkpp2//1LLPIGT/mtw7R5paNIZCDF/H66TdJ11uNowqmVtv5YpJBXgIvUWVbXSOL04f7t1Jpm458BgZ/g9FJl9YRQuAmjYHR1/6zTV3t1yh0JPk3FJPShrqIVIa7vGx4TN7Ux5dnOYgcq78r1Jk9C+pI6qfUIYIPZ3VBXbUZuD1lUJ2OAnwEzwBP9FWf2mnHuk+MAwO2WWsQTXfz+PwKCo0Fb50spQEoUnsa45BXox0= 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)(1800799024)(23010399003)(366016)(376014)(7416014)(10067099003)(3023799007)(261009223027099003)(11063799006)(4143699003)(6133799003)(22082099003)(18002099003)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QVl4Uk9kMVNFWW1SVmFzbzV3K1BLK1RKc3hqdDZIMFVKdlp4V2NSb2NSeHJP?= =?utf-8?B?NThIcDZlR3lKcnNBSGRDeUI0U0NnV1VTN3g5cysvZnpQb0hhNWwwSWVjUmtp?= =?utf-8?B?QzYrWEp6Zk1acWRkcS9XekFsbi9pZmVmclJTRmxvbDJyMDJaNDdKaklXaEox?= =?utf-8?B?S0hZMmJieTQ1c2RHTko1MU1IVzh4N1RBTnAyYU5BUDR4NlZJaEdGSEd1V2VM?= =?utf-8?B?OXowY282c0wzRFZ0Snh2Skd2Qi84QnBnVUZwZ1BkczhXSThHU21Vb2FabUNl?= =?utf-8?B?YURzMWJ0MEpQM3krVy9oVW9jeVlOa0gvS0UyRXV0cFRJNW0xTWtDRGlmTk5D?= =?utf-8?B?NUNrVkE2WGwyT1AzR29Ub3BwZFV3cm1VbFZhakROZ1I2KzdLVWgxSnNDYzh4?= =?utf-8?B?ZTdQbmpyc1J0anBqRWV5eWNoQXlic1M4U1luazFwR0dUYmx1cWQ5RGtUdW9p?= =?utf-8?B?YmYwUHc4NjNLblplTzV0LytvNVQxSk44c3YzTEYvbDFZcjExMEJjWDRqRk9E?= =?utf-8?B?TUpKeXpYb1U5c3ZlY09nNFRYQUdocVJwa0ExdURrOTZMamlsN2NEWk9jR3Zo?= =?utf-8?B?OXZBRlZjNzRiTENob0RvMHZ5QkxTWVRXK0NxbXl6b0g1UlE2TFdqMVVNUHlF?= =?utf-8?B?NSt5akEvRzFva3E3WllleHQ1Q0RmVEU1K0tOU1ZuQ3ExUjdzSFVMRVYzNFhV?= =?utf-8?B?aXNaZjBGallvU2NCejZ1NFFrS1NHbTYrOXJHYlU4d2dMNHFBeEJUYmM4VStH?= =?utf-8?B?aGFUUnVSRDRXUkFaSE5NYnQ4aWdqMUxUanpsaTgvU3hQV3dkY0c1T2E5VCtS?= =?utf-8?B?eFRTOEg4ZTRrTVJTOVhmTkdGaVJCbkYyZThiUFF2aWlOVlRHa0Mrak5MY3F2?= =?utf-8?B?TlJBaWJ3aENLdlBCMEJURk42TjZuczU2YjNad1ZjQXEzNWpDN3ZwcXhPQXE3?= =?utf-8?B?WnE0dURuRDFSQjBmbnFBSkhoRXNlMy8rR2JBK2h1dDBCamFXNWRPMUZOa1VR?= =?utf-8?B?VFBRWDFJMWVvZ1d5TzB4V3VZaXUzalJtTnltUlRWNXZ2eis2SlpVM045aDBh?= =?utf-8?B?SXNXdkRQNUhmT01ablN3M3RLdG9mYk5nRWZBbnIxSWJlYzNZbnVVRjlSTXN2?= =?utf-8?B?VER4VDlnNHdNUE5BOGYzcklJQ0x6cmttRCtWNVAwa1hCYStIY3hLdllENmt2?= =?utf-8?B?RE9oMDAyWXdrbVYxMCtWU0pmdEorK2Q5SXR5cXU2cEdnaU1nRVFTazRUMy9Y?= =?utf-8?B?cXNHRVRFSWxSdTQwVE5mOVQyOGVqMWE1b3NFb0FLVVROUmV2QTRDOFhNUnRW?= =?utf-8?B?eEdoaHFRQUM4SWJaUUtzcTZMaTAvdlNORkIxZ1hUYWVpUWxLcGs3cXBlOXUy?= =?utf-8?B?VW95K0lKd29WcVAwcW5VQUVvcUcvaVFZNlJxWXZVQTNDOEVTdVNuUU5HUGFO?= =?utf-8?B?MmcvVHBIejdxQ0JMWVNVTnBWbVJwaEZrY2hvNGZqVzYzWnhKdE1CKytjUEZY?= =?utf-8?B?RWExNFpqTENwcVhWTk5udmtJQktyQ0FqS3dueHpjMkFPMjlWUTh5a3g2S0Z6?= =?utf-8?B?M2pvVzdyZHdjek03U1RiUGhUNlQyTk5KRWFjVVd1VUlldk9MeW9SSnNEU2Vw?= =?utf-8?B?Z3FLYm5QZFFBak9kWUFPSU83cmhRUUJIVUFBTlg0VUpvcExWRHUwUEtkZktY?= =?utf-8?B?aGhpWFRKbUg2TnRlZHhGM3FuWlUvWkNUZGZmRGt6N2V6elRYMDZySFU3UnhB?= =?utf-8?B?SUNJYTYyS09EaXdpelhpaUFXSnR3eHJRQTcwTklzVklnSndXdE5Ud1p2QWFr?= =?utf-8?B?K0Nlc2FjbWxEb2loUjFpMHdzdERhMEJlbkh5Wno1Y2R3ZWFnNUhtMmhudVVi?= =?utf-8?B?Y3A2cmhlUlFBMmo3Q3FKV2pjbjJnL1RHME5QZkxjZmFOaTR2bGxocG40Ti91?= =?utf-8?B?ZmJkTlN4cE1RdjBDdVVVTjlkQUhla2RzV2Z3clVOd3JJOUF2NHVBcHZrbVYw?= =?utf-8?B?ODRBcjlNY1M1ZS8rRnhQbXY1eFRPV3orVEE4bkxNakdOWTNkYlZDcFdGTm83?= =?utf-8?B?L0pDMVFBNWU2eGxjaVBiTnEyZTlrTW5tN2JPK3QrcnFFcGxGQ1loY2xVVFNr?= =?utf-8?B?THBKNWNCQUNkUVdqUm9GL295M2NkN2lIL05hZzJ3OGZ6Y0d5amo5UlIwaldL?= =?utf-8?B?d2t5QnMwanZsY0t1Ym5uNTZjTnRVSGcwU1BTSG44Q2JVMEdTTGZWZUx1OEE1?= =?utf-8?B?cGdKZ1A3RTBTVVdGWXluSjFkbjdqY2c3RGgyWUFwemZPSUNUdjY5U1piankr?= =?utf-8?Q?knN8wgf1D3Lnk5sS9S?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2db3521f-fb73-4751-0131-08df28c563ee X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5320.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Oct 2026 01:00:36.2054 (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: ErFCChIz4F0RNMtfoR2jHMUgEitYFPKQdChDCzJdELLc09PaiEy8urvbYleowpaT X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ5PPFEB07C8E34 Hi Reinette, Thanks for quick review. On 10/12/2026 1:40 PM, Reinette Chatre wrote: > Hi Babu, > > On 10/9/26 4:44 PM, Babu Moger wrote: >> AMD's Assignable Bandwidth Monitoring Counters (ABMC) are configured via >> MSR_IA32_L3_QOS_ABMC_CFG; MSR_IA32_L3_QOS_ABMC_CFG.cntr_id selects the >> counter the configuration applies to. The number of counters a platform >> supports (the number of possible values written to >> MSR_IA32_L3_QOS_ABMC_CFG.cntr_id) is enumerated separately via CPUID. >> >> On platforms that enumerate more than 32 counters, the current 5-bit >> encoding truncates the counter ID and misprograms ABMC. >> >> The AMD64 Architecture Programmer's Manual [1], available from [2], has >> been updated to widen MSR_IA32_L3_QOS_ABMC_CFG.cntr_id from 5 bits to 12 >> bits (the published revision 3.41 does not yet reflect this; a future >> revision will). The CPUID enumeration reports the maximum counter ID in a >> 16-bit field and may therefore report more counters than a 12-bit >> MSR_IA32_L3_QOS_ABMC_CFG.cntr_id can address. >> >> Widen MSR_IA32_L3_QOS_ABMC_CFG.cntr_id to 12 bits to match the >> architecture. Cap the enumerated counter count at BIT(12) so every counter >> ID used by resctrl can be written to MSR_IA32_L3_QOS_ABMC_CFG.cntr_id >> without truncation. >> >> [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming, >> Publication #24593, Revision 3.41, Section 19.3.3.3 "Assignable >> Bandwidth Monitoring (ABMC)" >> >> Fixes: 84ecefb76674 ("x86/resctrl: Add data structures and definitions for ABMC assignment") >> Signed-off-by: Babu Moger >> Cc: stable@vger.kernel.org >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 # [2] >> --- > > Reviewed-by: Reinette Chatre > Thanks Babu