From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM11-BN8-obe.outbound.protection.outlook.com (mail-bn8nam11on2063.outbound.protection.outlook.com [40.107.236.63]) (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 E7D3C15574E; Mon, 5 May 2025 15:01:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.236.63 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746457284; cv=fail; b=AXitdysfMgEURosjKPAkfNrG80Vtt44LOJNidv63Kab6Asr/EIxcY6So7BOS4zu/VKvAeWAKs1/8MU9lVnAK0sf5KlYX7uXEsbXuyoA9EsxA9zB7a6GGjS15sa0YfLL8Wc9j/sXW8OGfRjJz9qKuzmsY/2468keBFan7zpdTwrc= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746457284; c=relaxed/simple; bh=+OabkcfUG86UwqQHfsYoU9ISV6ITWHhNeullEGpHkwU=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=PIllsQvwE8tKMBPdTrZx+XDN+S9rKy9+XxoERFhk11w9NOwOo6I5fMkcTylznKAvqZuDxEBvEKrOFvrUuPjqG2DrN4JuMr3dvazm4XXbSLBoFAGpP71uajlM8YDebh0wc3/itzqcGW6iCrQs8mpxDQLtnOYiG0dATjtRu7Q7ey8= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=Tt1jbWbb; arc=fail smtp.client-ip=40.107.236.63 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="Tt1jbWbb" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=HuDQybL4fu1847F2VNfgDTW7bU6EvA2aS89bS57xqO6S7I9uAUJiJDz8KMPJ2J0OG6x4ABlr+8KwV3W5VY6aU4Xoz+LeHd/R9s8A2Xx7fSJEzZVC8lOlwWgAxPlsfV4ZbZcBSzp1nlQrrYdSA1dSyCmrfYfGB2ghg8twcldCuZgwPR3yxN/6rAGKG8jbmC4NrhncHQRN9vOsOZHdD9NQcIvhNpMX+s8JSjNPSrZfV3MmXcmn6lmBnfs9kTDWSOE4Q7B1qEmKGji8avHsMxdEVlLccM4Br+j5nW7A1R1TUQEMJbj3I2bik59dF9Ho87JVjkikQ7tArLXXYHctxGxldg== 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=2hUcbONjA5JopsfleQ3q+kAo/FcAr+FGSXjXd+tCe6A=; b=AMkijG7mYG+tMu57FzSdqBlocvD9bXDfsxNTK1E4NIXEkqQUSi6waVi7j1mcbrbBlQsxScfO/N5CVR/udlQ+YwrfX7OSgNuCy/+QeuHJBsUNEn1v3v/245mg10fclPXHxABc5a4sg2FBZnO9e8GslmLFlotekRXKU73xRs075WPPiDRosSYsChT1fjJU2KlovHx9NfB3+FxkUTmbqpBdDslazrAnbWh7iN16wc+t3hKgprFTJ5j8EYgQcNQRCvBrFsqfub79Onk7uBzKZsegzEi0WYZC7xLLLy1FtLorxBilhTKpp7RU7nxNCSN1sC2besONXcZZGijMBYWKS79M/A== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=2hUcbONjA5JopsfleQ3q+kAo/FcAr+FGSXjXd+tCe6A=; b=Tt1jbWbbqcILXJ6aWOsGmESS4iku8skAlsy24VX06LiIeaBPbK2DMMBDlWBrzAj+qtutIyKr4/+YWFLUj9KVwTnVa0JqQP5I21rciOjtFt4SutGYYHzsJ/4B/Q6TUf8VdUvaUilqMTVY9IGqNhxKPWVzDiouYNg7E+zcqjHa3Vkpynnp9FENm2oLrp++up1vyQeLwtuaN5eA21uXvn2TBA7CFjJf2xJ5jWfk7Zgq9sSGQ9u/fI4iUT8WZ52F25TLYCfu/7Kd/ccNfvH/35nbVCvW5NsG+/DZ9hd7sb1yv/zM1IxTCs82c5YSrqyIu2dtAAdFCsAZRf2HZtS0dCky8g== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) by DS7PR12MB6096.namprd12.prod.outlook.com (2603:10b6:8:9b::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8699.23; Mon, 5 May 2025 15:01:12 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%6]) with mapi id 15.20.8699.026; Mon, 5 May 2025 15:01:12 +0000 Date: Mon, 5 May 2025 12:01:09 -0300 From: Jason Gunthorpe To: Nicolin Chen Cc: Baolu Lu , kevin.tian@intel.com, corbet@lwn.net, will@kernel.org, bagasdotme@gmail.com, robin.murphy@arm.com, joro@8bytes.org, thierry.reding@gmail.com, vdumpa@nvidia.com, jonathanh@nvidia.com, shuah@kernel.org, jsnitsel@redhat.com, nathan@kernel.org, peterz@infradead.org, yi.l.liu@intel.com, mshavit@google.com, praan@google.com, zhangzekun11@huawei.com, iommu@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-tegra@vger.kernel.org, linux-kselftest@vger.kernel.org, patches@lists.linux.dev, mochs@nvidia.com, alok.a.tiwari@oracle.com, vasant.hegde@amd.com Subject: Re: [PATCH v2 08/22] iommufd: Abstract iopt_pin_pages and iopt_unpin_pages helpers Message-ID: <20250505150109.GH2260709@nvidia.com> References: <376566b4-6c13-45ad-b1e5-8cfe2de437bc@linux.intel.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BN9PR03CA0881.namprd03.prod.outlook.com (2603:10b6:408:13c::16) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|DS7PR12MB6096:EE_ X-MS-Office365-Filtering-Correlation-Id: e0b18626-7aa3-46e0-f26b-08dd8be5ac97 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?vX5COlzExasYxqOwZiNvXgPWuDhpsEvy7TMOTnWiphkpdoWg24uymEvPkLga?= =?us-ascii?Q?y9Ajjei1fgDpmMpVOXYrMPh6EL9ikQJfy3NX2NpwNjIWW0UXu6qffW1SS1uU?= =?us-ascii?Q?9Pikx7T9smoPN3hRgNJRQiLxF3Xccg9m27k63mu2llVrJca5hA5GzCr5cWKH?= =?us-ascii?Q?I7YP2GNZveIfJjlU10q2G6xB6ipJyRaqnnFOUUoffj0LHlLF498LzfS/vc5Q?= =?us-ascii?Q?ZS+u3BfV6btPLyv2L6Y7MA/44ZviuIg6D0xD8Lla1SIZku9i7fhX0duwX0lh?= =?us-ascii?Q?Ejo4lwq+kuyNZCLSr8jo0ahaWLT9RI9k3KQnolLjtqQsFYPdNCkruNRlQdZ1?= =?us-ascii?Q?Ohk6Ne3bR/icGEa/l4zuFQaxTjrjrkrBgypQMPXOiD/4lxnlWmme4i9l/F/u?= =?us-ascii?Q?hVERRbCHqe6cZ7KIl2syP/AlSZgeC6sgwFsnbPu7yjmDYysBYZ/RTLMlifRX?= =?us-ascii?Q?VuwAbRMYQJ7/zC8LJ95469+PwGcBJC1SAjRGFsNk2K8Ybd7rXHfgW3/7PSxJ?= =?us-ascii?Q?lTuLVFhPYwi1OhFefBGO4EyCePWjNNnxHZksYWMQ5DYB3jOQdXojxaWQOWd1?= =?us-ascii?Q?+1vZyKjM4GZiAwcppqaJiluLb6C6vVtsOmfvTybF4sJOgzDkMfi/3Ix+s2m5?= =?us-ascii?Q?TukVmZPlpR8YKvWoaiXlkKk/qXIJj5DH1tRmLyMybHchUU/Xjr6ZmeK/2S1X?= =?us-ascii?Q?1TyaxMa93R2HmpKyzSiDrgaeurqI4NYQrwypeqsezDt5r3pT40EStUG9wpr4?= =?us-ascii?Q?iZZxxAe5iszkdSgtrWl8wrTOZs6npKY+SnjzhYKynemC2ZU8Wm9XCZwPJRJK?= =?us-ascii?Q?tP0HRNXCddyg16oZxoWaw0x/6Zsyynal1ltUTt3PNH10+bjUn69I1JljPAlP?= =?us-ascii?Q?QmahSmphVmWVrhhwR9KpV2KtnzCpO6B7EzjZWWoGkGqdexjFmNtJDEPOfmw/?= =?us-ascii?Q?UXrp4+yHg0H2gXaT8IjNJ8+KzEVet0niEBDHgQLKQlGtz8VjD5zjYeF6XlZv?= =?us-ascii?Q?jEGd5N5bfE5l9n0+6Krf+6AkEpW86uHxTPpdbyuhPk8ROqO/xNhXSp9sYbB3?= =?us-ascii?Q?iYwqYNHfHiwPEQnbanF0AVQajvhU+0RHqncbCHp7TaSg6zNWEvUTgt/tFm3+?= =?us-ascii?Q?Tg40Bc50A87uM8qFQbTb4xz0Ql1VPi7zCNIyGg400ZFjOXhOiNpFcuC57gV8?= =?us-ascii?Q?IoUYcuUmZ1Um04cnB2Kclij2iqnrK0Mou3UfmkN2bKwR0lY19cJriJIIm2++?= =?us-ascii?Q?JWgB1C1/IZcZEZDYcFuHtkmobYUZidpXRVBbSwG0iXkqNwhfjeEre+3Mh0Gq?= =?us-ascii?Q?zWddENN9rKwlORuJwgokoveLDZeu/q3ENofEmhGbHNwcmEVaLTp02Q05pnju?= =?us-ascii?Q?r8qKtQIJftT6X2KvoRBrUwCStwwCqW3QCMvMYDb73OiWyc/37Ek3tFCMPWU7?= =?us-ascii?Q?MGM9yWT7vDI=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB8659.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?QHyENSChoql/ytnWGyZ9MUJJ6ddtzC/WaSfgE7SQgzTkRiQLE7c7pdtC57Tv?= =?us-ascii?Q?4l2O1YiZHONvmXtlM5kV3o5U+w/5eNBr/WvSQguEb8YEkIBuP88JgIVxShlv?= =?us-ascii?Q?UVLTtV0CUElbcMDhEHJUohE5rVjv8p2rDH4AprObdSa3kVcl3chNQLfvAc/Q?= =?us-ascii?Q?KX/z3sCGg7yLtj44HEOqYInNMYgxLQq0wnXBFHu3R7GltzWmSRX3F8NL+j9O?= =?us-ascii?Q?nDBZmwXQ4GDFfGB+IOY9N+qZx2jP0cFKe2MwdJ/BaWyENU7r2+zMKGJF03Bi?= =?us-ascii?Q?GO3XjQVm1N93zlFkTECYuLO+CCQY9mxWP1YFjhKsqmdL2pPhKxWWPKfAVf3P?= =?us-ascii?Q?o6gDao+Eod0tfEUomQN7xumYVK0TbFFeo6hy/2B2k0yTHNGHFa0L6JRebL1B?= =?us-ascii?Q?pkhauh17hRpU+rFoPVZTOo7giaBxTMjzsHUFkhjhK31I6+mKdetuCYDdjqlC?= =?us-ascii?Q?GQa7tUZ2+Bqp71oMbuEMcdeBKULUemghRK8EIoeNhp9HZdjNN6LOt+sfCOqU?= =?us-ascii?Q?EbPwQ8id65nYUvdkuP7NqlwSE6QOyRXQAQEbI7Dc0imyiMTLHIucFoyEHVy1?= =?us-ascii?Q?oO+f6X0fqFI/XH4Q9UmEHm8SRBX17sT2vShpsziYHTtWerqOS6vIfmd/XnRT?= =?us-ascii?Q?LJOlGlDZappwJrt0+N8kNSrvXgfwda25i//FAhVEMHSRgJBVNBkeb/J90oh2?= =?us-ascii?Q?8gug8KieF0tXsXctBlv6wnBvkuSRW6+EN2n/4Pu/kMJif3dnrbCbL588OUNC?= =?us-ascii?Q?xTmuhuscD8WHcfJIVtbbkWcFtdu4aX50tpbwigpNxFe30l2ijkjCkLZB9xsU?= =?us-ascii?Q?WNI0+T+Ca6Zkf0Hac7qJ5/K0q5Q2h4v3k54YLk0xFH+4KRXDOZEzkHwzkx2z?= =?us-ascii?Q?lg+c1fQCqKwNqDWXdGauGQuAHqdKxUyBqMjQ2ZMpoLlI0QfSMtAOZcXcIquW?= =?us-ascii?Q?HYN/4S9Lg/pJ/J5fdjDuB1dmKnhKTR+QVRv4GlvE9SNUmBbRuza4ZlyJb8LN?= =?us-ascii?Q?4DEx/KL6d7QNfndq+2VATOY9UCeEUbBOcrESWZ1Vvhkexa/vXUlEdfxC/CMI?= =?us-ascii?Q?ZI6Ozg5u4bAYq9E2GfsSCZcUzKRX7Sxj4omfsFmJQSTy21x1LPmQXCFCKh4k?= =?us-ascii?Q?oer+swh8ykJtR6dWsfhaHITuVTh5tqD+Wv40A8byozbN4HwPCL3aXbfI/kDk?= =?us-ascii?Q?xwwFulB3rdJwVGt0BCgLPW2TDE2qrzYLu4UEplLYXe0T/BeDT7PIumJjo/4w?= =?us-ascii?Q?G/1nP3zPNPUjeOm8/kM8IfxoCxvkWMyiA8UViCW8YE/mt2yNREgfB8Ogypy+?= =?us-ascii?Q?EikupOSX55pzjbm+RauQrcm0HvXzNOwQjvZQhLy3JDIKAvdtuGlg6ge2tpwK?= =?us-ascii?Q?6LC2c9iDZrhFtf0T2f6l3qPkV4Xllyev9vmsNuklItzQmkaCzLd2jsYc8gfD?= =?us-ascii?Q?VIi8ASP4O+kXhgekgmOYLKswEC7ZTJYtgvyzySMKceDyGS11kwftbYAx9gL0?= =?us-ascii?Q?xB5AB2L9eWRbd8Vk5EeK4AyYjDaIaACxdIkCKmWeMZ4U4qXbMi4tSVcMAAIp?= =?us-ascii?Q?MNRJbWObhgn7U2T9TeH0d5tTpy5Mk7X/oTNcXQJt?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: e0b18626-7aa3-46e0-f26b-08dd8be5ac97 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 May 2025 15:01:11.8677 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: JujdOqAaFlYsQ0EWGuAl7U9/2VXsAw+B2LRg83eFnkQXocW6wt6bTKKgWqfvscLh X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB6096 On Mon, Apr 28, 2025 at 10:41:45AM -0700, Nicolin Chen wrote: > > I'm uncertain, but perhaps pr_warn_ratelimited() would be a better > > alternative to WARN_ON() here? WARN_ON_ONCE() generates warning messages > > with kernel call traces in the kernel messages, which might lead users > > to believe that something serious has happened in the kernel. > > We already have similar practice, e.g. iommufd_hwpt_nested_alloc. > > In my review, a WARN_ON/WARN_ON_ONCE means there is a kernel bug, > which shouldn't occur in the first place and isn't something that Right, so it should never happen from any ioctl path and syzkaller should never trigger it based on system call randomization Is that what this achieves? Jason