From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2063.outbound.protection.outlook.com [40.107.244.63]) (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 98A601E377F; Fri, 6 Jun 2025 13:39:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.244.63 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749217173; cv=fail; b=eHCDBAB+3ICQEyUMUGrQT8QeVGmz32iDAxn8dFoZBpGkb0RJP28Wl0x8FIKzCdsGJ5l+xHvQQCVdpyOXjT7BMmgZAAO73VckPnwkDq7BkE5/8N0gqUYZD721OYgBzyZJl9PiDUZBNxK/iv569L/eUsCOauEx6xvCFsbm3F8Bs58= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749217173; c=relaxed/simple; bh=q1bS0cdoduxIw/b/8JKQ0fIBeSoc4C/uvIYxpmn8l60=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=lu7hLZ+mJWm6E7FvXsunEWnD9GPdlTdYUG7TCiDDiTsaTDPobx2zGaAlfBlgQsMotBN4y+YnP5XwQVQCoXKaBlWinc08BNL2aDl7Z+eRPYGt7MbdLHk/LDISEK780GRl72I4K75sJUimicxutna//q494V1yjXuB+Yf2iLgK0EY= 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=vcmcOqkf; arc=fail smtp.client-ip=40.107.244.63 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="vcmcOqkf" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ARDnXNNeoCjWyRCRjnpXz2Sc74flRZ3F4uzIfJbQSij1zHsSetUq9cJtHg3Cbithl4NPa0uI7UTR2Alts8LiIrSAn07GP7WRbZ3KHWYjdwM+aSlHuyC7R+0TloN4ilcQpWiRp+QAmGDcNCBzrggykwbDqJguqfnyOpE9f2+UcuOElp2+l7ILeh5LIsSPMk7FLnXLr/zabtgmAy+3VyDZKQx1gEjgugaeysEbSXalW+TmdtdiyoePq0bU7xpXKd49ktv1wcDnewGotnyAFBbab65+2HaJ9r4cvxAexFs9zWQylNuqeOVopdZdoMJ4+7H9E+DD56KhUU7iPRIVF1xKUg== 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=DaBZJ8mkjen7s2aOqjWyJfv5nHueSFMG0s5OhS97zp8=; b=wGAhgHiR7zYDMKZ0huTkpYpHe3vhjPop/8/GkH/hRTw+x8XaFc2vPkL0wB5kFtRngM5GkMGHAGWKM928dqMpbe84ul/8JnuKd2RGbvSyw2YYMgT1GNm4t5Ar4rhfwk8l+KUhjgJsiMUGOZE5wYBLPamxUY+arUVUd5jyijB2gfxYHicoJdre4G2z3KqWpcHiuq3nrQeGspCnjz5kekntr2WvZ5N2N2CjHZ3aEgtzIbYD5ouxMFDNWFA1jtnv0ke16nanIIGnRvx6JK79qXd0BL7wTtrOPR5bocTdj9oZv8B0kEbjiWG+tHgq9mnHvjrd4BYhUAQllyhUeFppm5uleQ== 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=DaBZJ8mkjen7s2aOqjWyJfv5nHueSFMG0s5OhS97zp8=; b=vcmcOqkfz/8GkyGj8R/6xvoCFt5taoijCh+65et88IawVi/wNBvTYzFR2ajnnL5hJR3YmHiIpuorlH7OPJ1Nizo4A2pAQjrlahEhMuzN5NyG/xjD48Y7jlByjSj9qy3yxbArZHq7a0A84nYevO7eGzhZTO8kYyIGCHXVza0Yp6k= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DM6PR12MB4202.namprd12.prod.outlook.com (2603:10b6:5:219::22) by MW4PR12MB6754.namprd12.prod.outlook.com (2603:10b6:303:1eb::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8792.35; Fri, 6 Jun 2025 13:39:29 +0000 Received: from DM6PR12MB4202.namprd12.prod.outlook.com ([fe80::f943:600c:2558:af79]) by DM6PR12MB4202.namprd12.prod.outlook.com ([fe80::f943:600c:2558:af79%4]) with mapi id 15.20.8792.036; Fri, 6 Jun 2025 13:39:29 +0000 Message-ID: <894872e2-668e-4c33-a701-5dd641abfa5f@amd.com> Date: Fri, 6 Jun 2025 14:39:24 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v16 19/22] cxl: Add region flag for precluding a device memory to be used for dax Content-Language: en-US To: Dan Williams , alejandro.lucero-palau@amd.com, linux-cxl@vger.kernel.org, netdev@vger.kernel.org, edward.cree@amd.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, dave.jiang@intel.com Cc: Zhi Wang , Jonathan Cameron , Ben Cheatham References: <20250514132743.523469-1-alejandro.lucero-palau@amd.com> <20250514132743.523469-20-alejandro.lucero-palau@amd.com> <682e3c7129fb0_1626e10062@dwillia2-xfh.jf.intel.com.notmuch> From: Alejandro Lucero Palau In-Reply-To: <682e3c7129fb0_1626e10062@dwillia2-xfh.jf.intel.com.notmuch> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: DUZPR01CA0082.eurprd01.prod.exchangelabs.com (2603:10a6:10:46a::10) To DM6PR12MB4202.namprd12.prod.outlook.com (2603:10b6:5:219::22) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR12MB4202:EE_|MW4PR12MB6754:EE_ X-MS-Office365-Filtering-Correlation-Id: 2b14fbf3-5981-449e-a9ec-08dda4ff8f79 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|7416014|376014|366016|921020; X-Microsoft-Antispam-Message-Info: =?utf-8?B?MmVFZWI4Q2lGMmt3M25LTGlqR2FBbU55QVRwYUxmWlV4QjV0dXJWYzVwY2FO?= =?utf-8?B?NEVqb3lIRHZSVHAyY0NqZ2oxdWVtMWtWUkl3TzF6c25HUFY4TDhYSGczTnp0?= =?utf-8?B?UDR4RTRRRysxZW9oOFRpcldHNjVaZ0EvYVRPRTVsYzZNamhTN2p6WlpCNEg3?= =?utf-8?B?OVZBU1ZhMjBwSW9LSEsyTG9pcXR2aEphMVh4N2h3b1dzVVg0eEVSeUgxVGl3?= =?utf-8?B?c09BL3dvanIyNkxoOTRNMFUyZXlDR2g2dHAvaGZGRUlXbkZvVzJkSVZXaWNh?= =?utf-8?B?dFRudjJFL3prbUVFSnJONk44TVFyaldiRWRlTjNIMXJwcmg4UjFHcXVMeGN1?= =?utf-8?B?RGJGZTJZVENMM0xnTmFRL2YxUjFrZWdqQUdRNmJuZjErTWhHOWNUMkN0cTE0?= =?utf-8?B?aDlxU1JqVFQzeXpiQWNnd3pZelNySzRHZjRHaHprQW5PSTRBekxPbkxpeHdO?= =?utf-8?B?Ny90bC95RkZtS0tEeUd6RXU5Ry9ERmVKL3RoakRHb3hqdERDUm50TW9EeDRH?= =?utf-8?B?aGw2Q1ZiWGhXU1h3WmhOUUhKKzRmUTI2NVAwN1ZDeGI4MVpHZVI1Wk1hSDlG?= =?utf-8?B?MkwxaTE1d3A5RCt5bU5KNkhJbU5DUnFpN0o4UjhZZS92Q3JiSUE0ZHgrSmUv?= =?utf-8?B?bjZvVFV4OWdGSHFHYi9nNmc3bWx5L2JpeFhqS2hJb0RlZkt6UFoyaFVQbTBM?= =?utf-8?B?WFNVeVdDTmhCVm9WYmdJNXhoRC9HaCtFbmU2VE11UjhMYVJkRHdObjA1WWl3?= =?utf-8?B?WGhjWFRDL3cxM3VjdHp1dG9DbjJTMGs2SDhMTW0zYlF6bmFUUzhNMmVCT0dV?= =?utf-8?B?NFNJTVRHKzZxdHNTQk4rMzJnVjBzYUtkRjBneldyL3VlNEJJVW9yZCtldXJ0?= =?utf-8?B?dlBtVytRVmZ5YXdNU3ViWlZDOHpaRDdxcTNZeGMwajFEVHl3RzBjeXcxL1Mr?= =?utf-8?B?TFc1WUx5aW1qQWpmTmNIeU4wTDd3SmdCL0o1NHY3T2l0L24ySXFMU1dFYlN3?= =?utf-8?B?ZUxSNjJZdEp5cFlabjNtS0lPbDY3dWRFVGdDSHJhejJnVjhPU1RYZkY0U2dw?= =?utf-8?B?NjgwWlJnbUF0VkwwTEltaTcvSVR0bncxRjhzT3pmUXorbDJBSUtDd3Q3emJZ?= =?utf-8?B?dUJ1ZDhvMHBENVVxNlhLU0tobzYwT0VVVTNkN0lBZXhzaWtTcDdYd2Ztc1Q2?= =?utf-8?B?bHNjMDdGRDl5M0lDQTFpRFBJSXVRZndsUkxhUzVKek5mWkJmdng2eHJvQVRF?= =?utf-8?B?K1JET2JKRVBDOXlOQUZkMmdZSUVBSExBN05EWmZRWlU3amMwYjhFa0hqZlpX?= =?utf-8?B?WHhYY2N2aGFOb08zRHRyRUY3UDM2ZUw0NlZubDRiRU1LcS9vR2gydnZ1MkUr?= =?utf-8?B?bEE0bmQyS0hPNHk5RlpnMnVBWFNuYXdodGVpa1ZwODJkZ0pEeWxsSDF0SFh0?= =?utf-8?B?VjJZcGoxZWN1b0p4WW1PbHB6WXRXb3IwTldYK1V1eVIyNzliSkIwWVBsWkl6?= =?utf-8?B?b0pGTndhRG54U08wT2NmaS9ERmxrQll6NHZHVEZ4elB5VTB5eWlmcjE4b0VH?= =?utf-8?B?YlpoQ1d5MW1mYXBjWU5yVFd4RXFhQkZRa3hpQUptZGJXcGJQTWNqdE5FSW52?= =?utf-8?B?MXh1cFRreWJBSEh4ek1WbjdYVUJtcFhxSE5ZSTJia2VCU293K2k3NUh6UVpK?= =?utf-8?B?Q3dNeUhqdTViRkFYRUt0QitmNlRUTVlrVWIzTVZ0RGQ0Rk9JMk5vd3EyU0NL?= =?utf-8?B?RjVMQ1k3dS9VNDBZS3hoUXI3M1kwUUFwdHcya0tCbng3bHB2ZGtqYWNydXRE?= =?utf-8?B?cTZwbHhrQjdRT0NVakFmMGcxWDNhS0V2bHhGSDN5SDA3S1pkMlovRjNyZWJW?= =?utf-8?B?djV2WHRNM1JPbVpzRnZaK05GelNMV1hJcmcyMGZmN0dNT2hBWkMwdHdZZHdI?= =?utf-8?B?c2ZpdEpjRU1Md0FRbEk3b2NEeWZ6SklrTlBpTXpoTU5pNUszWTVFWjlYc3Vt?= =?utf-8?B?aVduM3Q3aEZnPT0=?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR12MB4202.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(7416014)(376014)(366016)(921020);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SStyK2E5TmJWWEk0emk3THdYU1VCeTEvVGdqZnFoWjZtd294YzBmYjdScjFG?= =?utf-8?B?RlJnTHVEWnZFUUZHOWlhRXdreEdjdUlSckw0SXRoaURlTjVGTUxGS3A5SzVJ?= =?utf-8?B?UDdRN1FzWFRQUTcxaVZBeDdDSGVIZjRveGU1NkxqYlp1c3ZpR1U5ZzFsb2VZ?= =?utf-8?B?aDh1a3hkbm5BSkdMck1EaXYxVTljdkhoMVRuK1pQUGhvQ21IV2xRY2E4MkxG?= =?utf-8?B?TERlRm00dkFCcDRkMGdMZFZjR3pSRU5EdkhaWWVLQ29aMjdKRjUyT3piR0lz?= =?utf-8?B?b3VLalc2RG1MSWhJajc1d3dQYjdFdlhwQVhNT3E1clBVNjNjYXVaMlQ0d1lE?= =?utf-8?B?UmRSMVZzcmpaVmM0SjduQzUydmFCMlM5eHY1eHgydkk5VGNYY2g5SWVYWFU2?= =?utf-8?B?SUpQMlczSTNFajdvOVQ4dVE5NVpRMVRaeEJQZ0Z5dFhCT2tnTkFodkpQUTcv?= =?utf-8?B?RVNHdC9sNDdydlU5cTRMQVl0MHV1SmZ5Z0hPT0pvWkN4YkpvWUNadmRDWGNz?= =?utf-8?B?Y0xyeG1UWXArcUtqUzNBN3VQN1dXbzBPZ1NZNWFiS1d4eVlxeXJMNFFEQXNS?= =?utf-8?B?dVl4ekxZU2FQOFAvY3VlOFYzamhsMkhuVHQvVWp2TlRTbm9DMjV1UG5ySHNM?= =?utf-8?B?ZnVVTTgrdmxxMHdDSkE2aU44SlJFTDBGRzlNVUNCdG1ZaU16UUtFMm83cXZY?= =?utf-8?B?aEh5dGhRQmRrSkxPZHMrRWtmMStlUU5nWk1mUXR5bk5jTDZLYmdkcHdpVjcw?= =?utf-8?B?M3ZaU0EyNjVhMlM3UFFjYlZkV0dtaVhUVjhubWQ3WjNVb1JkOTlzN3E4RXhP?= =?utf-8?B?VmJsTlRHMVpHd0ZFa1NBSFNkYVpXVmx1cVppVFlQSkpaUFhJdXhkV2JqVHdQ?= =?utf-8?B?NjBvZUVTSHhCL01FdmZ2S3FXQnZPSEVqQURFYlJ4RG50N2luTml1ZXdGR1dR?= =?utf-8?B?Vk1Tb0pqdm1GUCt2ZFB0MkhYYmRWeThyNEgrNU10WUt6TlEyb21YK3dmU2VQ?= =?utf-8?B?MWdTNTBlaFpjYnNMZmJiYUNrdER6Vnd0dWZzcDBSOEo4cXNpR3hwQzNGRkxI?= =?utf-8?B?K05Sei9MeGREMmM2MWJpT21OTmlxSDMxZUFqUUw2aDVHR3Zsdm1jRk9Qc3hM?= =?utf-8?B?QTJESHh1bURUWnB4a2lwNGhjb0pLSDN1UXhqQzRrNHNLVzFlLzFwYVR5OVZu?= =?utf-8?B?SnZ3ZURxenhoL1JITWNMRXdzYWsyYmF0SkRoUmduSENVMm9XVFY2dHh5bzJQ?= =?utf-8?B?OGtGR2pDSnI1K0JFb0xHWFY0Ulh4Y0JKbUI5SVJ0WW5OV1ppWGJ4aU1WbjBL?= =?utf-8?B?L1JCQ2lHekFFcW5HNFplNlU0Yk1nMnBOTW56L3dmOGdGc0Vob0FlVHA0MmY5?= =?utf-8?B?ckh4UUVyeVJVVGpmT2lSRWFGeFQ0cHA1NlBPTU9YbE9BV2pIVldTMGtrSEIw?= =?utf-8?B?V2ZhN1RHT3ppWnNiNGxtd0ZkMEo5eW1LeGFFaC9Dd0g1UFhIS05DcHJQd0hv?= =?utf-8?B?K2FiZlNZWnNMYTFEVy81UjJ6V1VFTUF1R3dkZVVGbkdFdDJMRHNyQ1VxVFds?= =?utf-8?B?NWtEaWZJYWFqYnRwTFgxdFFPVXprNXROUHE4TFFDMUNEeE15UUpXcElMVGpy?= =?utf-8?B?T0Y3STBzcWRHUnRyT3VMNm0yamM3NWtTbFlFSmRMcUYraWdFK3lxNktqdzNq?= =?utf-8?B?dXdpY0prTnFoSmtYTXcyWnRUV0tKWE1yd0dmMnAvcENoeVJ3USs0SUQ1RXhK?= =?utf-8?B?V3V5VjlYYUI5NTIwb1FhdmE0bExxR2lHYTdoTzh0RXhmT3lYU3FUUnd6dFFs?= =?utf-8?B?ckRGV2o1T2RYaUJGeURxM0I1WmtqeW5RZWtjU0VsTDUxV043Uks3Z3NYYUpw?= =?utf-8?B?ODFWUGNTTjl1Y3YvWThsVXUrcEpKYlpIYytWVXFLYWVJYmgzdzJTSDMzY3NI?= =?utf-8?B?OWpNMzF6QzFmWEU5YjZCZHFDMytWa1lreGRQMlRId3hBYUtjUjZLMG1CcXRo?= =?utf-8?B?aUpUUG9LVnpBY3E0cGhKNi9ReXNGeDZpam45NCtGbEVFMVc5eUpOaVdtR2dx?= =?utf-8?B?QVpEWEpib1pzNGpXZ0FSVVk5UmFML0loblVsaWNianFoUFBiYnErb3A5dzFh?= =?utf-8?Q?cRqeGoAFmXEtFhzRJnvUhbCdu?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2b14fbf3-5981-449e-a9ec-08dda4ff8f79 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4202.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jun 2025 13:39:28.9455 (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: 6Up76bJx0hN+UlWkQKnxdH9BxBSzj55Qvbo22laCsmZbMh3UpXJsW/LN+2oULOAHFQmUojqGNJ3GbZlW+8qlXQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB6754 On 5/21/25 21:49, Dan Williams wrote: > alejandro.lucero-palau@ wrote: >> From: Alejandro Lucero >> >> By definition a type2 cxl device will use the host managed memory for >> specific functionality, therefore it should not be available to other >> uses. However, a dax interface could be just good enough in some cases. >> >> Add a flag to a cxl region for specifically state to not create a dax >> device. Allow a Type2 driver to set that flag at region creation time. >> >> Signed-off-by: Alejandro Lucero >> Reviewed-by: Zhi Wang >> Reviewed-by: Jonathan Cameron >> Reviewed-by: Ben Cheatham >> Reviewed-by: Dave Jiang >> --- > What was wrong with the original proposal? It was suggested that although this is the most likely requirement from most of accelerators, it could be the case someone happy with automatic dax creation. > > + > + /* > + * HDM-D[B] (device-memory) regions have accelerator > + * specific usage, skip device-dax registration. > + */ > + if (cxlr->type == CXL_DECODER_DEVMEM) > + return 0; > > I really do not want the ABI presentation policy layer leaking that deep into > the region creation flow. Another way to determine this is if devices > hosting the region are not driver by the generic CXL device memory class > driver 'cxl_pci'. I have found a problem with this patch which precludes its goal (no_dax flag set after region probing). I was going to fix it but after your comment, I will just drop the no_dax option.