From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (mail-bn7nam10on2085.outbound.protection.outlook.com [40.107.92.85]) (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 9CB822F5313; Tue, 17 Jun 2025 23:00:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.92.85 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750201238; cv=fail; b=g6og9zbURbFBOJu0YufILIGDLjC8bZHSINN7JKBMIE9ujNn6hCTtCKqvX6VKqY1Sqnp4dB2T7JYil31onR4NxnnCipekD4lS2X8+f6GlJxTlg0w9Yo4WkkYdrDNJJYD4C+aua4BVLp3TWN7h7I3C7Lt36SI05CHgvdzOrzMLrbg= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750201238; c=relaxed/simple; bh=rc5kAbBDy6+2YqtiWIO4AgFKx/k9WKBZZkt4yYRkVkc=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=uyOuQtIJZOvzXvqg1VSAGiqgvgmap/ike3gXBRxFHNW8eUASrPZEvYkRP56UPFKSHsMrNwHmEhJggMB/RT/PGBYeUvqP9VT7CYxLUokmWpuNCiH9CuXWn6sPQc/nQ/cuyRXmZfwq7DEqbw2emz+DxqQjv6ja5ly9HKpB0hOvLj0= 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=i9e6Hwkr; arc=fail smtp.client-ip=40.107.92.85 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="i9e6Hwkr" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=r81iyxEUf9F+/KnbPkPzDe1T2t1vAIZMy89FoWThTBPzZZ6GrE4rc59S3ZvXUc8GBlnoPAlUOM9pUVLPDqo3ZWqUx3u7vpZD1uAFKbJfs2sWRK2x7Tn6tsy6IcRd85f6jTaWbZ4LuY32czhF5JuK0XOg28jsvh5SAbPHN50I2hTm6pWFJ8bPJmrgu+SjWdeDc+O2EtLZprXKRwwJFg/vhME50/QV1bKssPiea4FMsUMN/QhuItvJFqtc3B0QAqddZ40t7/XlCJta/eU/0UgBj2B4UlDmLZ/+AazOBNy3tbFKU+BOH49A5HBEhkMg3BzbuEfLGpOaqS7i3xmRyv2RkA== 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=ht4AuKaIgdFSVW7tipFQLlmV/Fyh3enNKqP0dEytqUc=; b=Jb3JLGYIdfBwinYGsQ7BXMpG768W3z1iytkvNCgVMu2TZ2F08CW4CMXu3sVnAf6W87NkCLg/yOS4qfVjQNh/DN4YsGDtgzEZBwJGhPWPot7opAMYNGcmtip+/H/dfLtXgX6m7q3osfo7B/0tA8hrlmGmIarDpW45zFkjCcEUvMnGFuJmlyWufsts3MBGtW+dq0g3zHHZ6b3vquoV8rJAnvufflmfu5gQTISge7nlhMEZdwnDLBc6nHojmar3NUK70smDnzkmcxGfn/WP0bq1dkJKcAeV9o7gB3LoHBp8G9QB8jqZ3AsDNgY5dDr6qXXliHFvJsulhSdldAoky8HT4g== 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=ht4AuKaIgdFSVW7tipFQLlmV/Fyh3enNKqP0dEytqUc=; b=i9e6Hwkrmn/FbIQnAgJP2dc+1SoasEZ5upPTEk/wHtwZxXP6qa2+1BHJORAZSltNNa5zzvQZAg4mYvATu8e7W0mDeKMmQA0tV5neMPCRKQUr3VigEYGlJHpo4XOA9EPEeZZgDvbC/oRs5570nEsqmEfGAhd8L4DbJBCdmW+IZ7hVwJpP27Cn5+SKH6vdV8zHUFRVHGbGyunc++Oks6MXLTid+UOftrsx6XNSJ6mgcMRMOKmxOTDTRUmDMse5gXyjaO/AyoJezSyTvFO0EPyZdz5/iqWyO7tvA6wh5vt4vq5G2boiM/Khq/aD8io7FQu69ZerH8aHCGd5Al1+uFD+WQ== 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 LV3PR12MB9141.namprd12.prod.outlook.com (2603:10b6:408:1a7::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8835.30; Tue, 17 Jun 2025 23:00:32 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%7]) with mapi id 15.20.8835.023; Tue, 17 Jun 2025 23:00:32 +0000 Date: Tue, 17 Jun 2025 20:00:30 -0300 From: Jason Gunthorpe To: Peter Xu Cc: kernel test robot , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, oe-kbuild-all@lists.linux.dev, Andrew Morton , Alex Williamson , Zi Yan , Alex Mastro , David Hildenbrand , Nico Pache Subject: Re: [PATCH 4/5] vfio: Introduce vfio_device_ops.get_unmapped_area hook Message-ID: <20250617230030.GB1575786@nvidia.com> References: <20250613134111.469884-5-peterx@redhat.com> <202506142215.koMEU2rT-lkp@intel.com> <20250617154157.GY1174925@nvidia.com> <20250617194621.GA1575786@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: YT4PR01CA0014.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:d1::6) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|LV3PR12MB9141:EE_ X-MS-Office365-Filtering-Correlation-Id: f6cdcc11-9406-4619-649e-08ddadf2c2ef X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?C1VR3Njr0mW6VL1NhOw3NIPxobof2bE5wNXzAIz+a1CmTxkVB5cLFsq/JqhA?= =?us-ascii?Q?0B2w1AHgsL9O1rPWPOMmBOGRVuvyB4557M3hs/C/TexAbQ84bnDVEYv2eH1T?= =?us-ascii?Q?EuHrmS2LekfTZt1psSot+3Xd3qqBu1GbWK5DyfjyfAlw67D9bK6SH2uGrE/w?= =?us-ascii?Q?L0hwUeVDuUDn1/1VFOQz7WbF1bVa5c76bAdvlHViDwVfqRT2eLn2uMrTfRv5?= =?us-ascii?Q?qAr0mcuYPh/Ncb+aGSAdAwPwhAB0Cnc/IoK0+Wof1wntkz6FcoNPPiJXGn/9?= =?us-ascii?Q?eOlPEZ3TyVhm3XnbQD5QW2KZtRT97uZNrfOw4tvB4WXwKZrekCn6nxPyGFw5?= =?us-ascii?Q?6pJTJgIRX56EjcFCsh9uSPrQMPJHM+N+xkTx7Inkbd0R+7nA/aVmNplc8gQ8?= =?us-ascii?Q?CNhxyKkaKtF83dRXhtFZr6zOhiBr3jNI6AT+Px+FWMYXSqekkr5cunbDP+y+?= =?us-ascii?Q?qFxEuLetYPWoUc1ijXQz1BN8EoFLe38fX860NoG9O8bUH9B5N/wojsuudOPl?= =?us-ascii?Q?MjJ8qUVafqdZ1+x8LMce2IQuTnFTfAFUKGB00NOotxn5avdaiHG5VWNbIuis?= =?us-ascii?Q?+piqiyClpZ8KcZVyXOBaPGZO061q0sEGSx4MppbwGmYCsmGzGjK1bVI42iA6?= =?us-ascii?Q?prMmOAHPAbuzMQJG4ybsGxY4Bf9T3Tm5/OwCl454qnLNwydLQyZLvmMRrcof?= =?us-ascii?Q?qia91fiyRsfCt6jXHYC7ofnqGbOsacy2PjEq/xi1NyQTQVKN4cP5phf8aTJa?= =?us-ascii?Q?CQb8SC+HnABPZH92wJ+2HQ4Td2WKktSoUZR1cz0F+MsinbVHLObyNTOnPkKc?= =?us-ascii?Q?TU8H5LNNLoxzQ2ZAXV8AKdZ0CXL7eHm61DYXj/HmRV01dKp27ELNQI3ymsnv?= =?us-ascii?Q?athu36j0JcnKVy6aottR8rFwU6IrLwg/OxDEzlll5q9MRyygX/ktKrgLNctn?= =?us-ascii?Q?qJ3TMiWdqsq4rOb37+ZPSt1QW7KZlQvhiTrd7I9vsElOIkWIjKXLWf3q3de5?= =?us-ascii?Q?O4lQTFMId5w8vfvZDfWz/r4J8kcyo9+4JrlhE9tV2z00cG/rKI/J2poxQDIZ?= =?us-ascii?Q?iz+HboCZqePCsHugpfdrjKd6YtsniugXU/TH0UczFhinFOF0eHTObNROrBCo?= =?us-ascii?Q?Vbk8NJBtmZDxbWEOzo3PdlBHl4EB4s1fiAf6LsTH9oYNmrP2eW9reEaJ6QA4?= =?us-ascii?Q?GcsXXNReXLJ1azv8CSsJdfY2HgEK1do0jA1o0Ib0PRuuZcFkObnw3psCGFav?= =?us-ascii?Q?w5IDwiCVv3X0f+Z/WFJVaXa9qau9bo1+JSe8mvXyI+kRJlghyzAAswdTlCYy?= =?us-ascii?Q?HMqBJ6ORTatIQnQ6i6pvDEbcHzTiHVnnoDRCqd8PTZ3XZM6gBvO+BzFsGD1B?= =?us-ascii?Q?a4JjaXCDqGUnvapdeji2P31nz/S6ZREzUopZNWjnCX23LWlEiIGjs5r3LtHR?= =?us-ascii?Q?q62sB5hcG44=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)(376014)(1800799024)(366016)(7416014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?DV0vGqnLzUNeYbi9OjlbE2oaxkFxT9UjR3jYn6ExKfsC/Tis1Io9IMMWl5Bu?= =?us-ascii?Q?zP87SYuq3+qcuKf4znGOCaYXgoL8gyC0YcXq7pintJVk85NzfDFGYh8FeHvi?= =?us-ascii?Q?VZKuFzSTx3G14usvDD64Gr9OuMKRzo8IyNO9smSK02MfC9O6Mh+66Sxr+xHr?= =?us-ascii?Q?qMOv6nDOTnc4lslGTLv/2XQedNgcs/vtEz6+CX/qDzv8S5Iy7Nq/g2P2caNa?= =?us-ascii?Q?o69SM+HjxTiNHALvpgIgDO2ieos10XOJoqU1pM3TZCwtSUCe6WkimcVM7xwu?= =?us-ascii?Q?M/fV+V/KglUS2Iuhf681b+UDLCu7CrmJvBMEIKKx0m9x1/wFiIO5ktZvaqKc?= =?us-ascii?Q?dIlMWOKGCzmP4FE7rFiTpWuUs3TLqkHkBHmFLLQC+7sBLhIJJtbAmxMJ5P5J?= =?us-ascii?Q?s9o8vGYLPlJB3POljbvwhYrIPmEY+pfBUzMBulu9PJoeQW1G5xesRZIGGg0i?= =?us-ascii?Q?hsOc6AlwAXqMlIj/jUZ/BdXoX1KMiowGoHaLQh/I/CWVl/5g/RNeMRH55QbM?= =?us-ascii?Q?zAPp1IRi8Z2BYuag2LSofnJzwxKTEkFqHI861n4O6DHAeM5kAtgHlTfarM6v?= =?us-ascii?Q?8Jl4OQeh/vYZ5oVsK7Nop7rGUB/2+PP4T70ethJxAmmTOrx4pN7ohNQQ4uWJ?= =?us-ascii?Q?hlTnv3JiHHODyyuBXXltKK8D+RSSLQhHjN1DnxCrfogI7jawFhKpqPIkVkbJ?= =?us-ascii?Q?Dq20mN81d97E20y0injXBWMvqbDi8YzQ19jo/j+lXYpfC/h2Lxj/IxnbN+cp?= =?us-ascii?Q?XndGnpXVDC2gF0awP+J0eBQeYIJdX/atHhLRmuW8BPzoNuhnd99vgdKpB0NT?= =?us-ascii?Q?A1zyab4YDCp3cCjWdxu7cwDT7P5i5CqHcE91o/tqomU/FozjQgT2aOCp8Ij2?= =?us-ascii?Q?oEvSS9QHH5WX24SSacabsgKXC0/9V2ngS9GH7qwMx6UHMEdiWiBNm/wAoKyz?= =?us-ascii?Q?GYYeXWanShcL5W3zd1g1vOf8gVonltA8KcEOkPctr3a5DrpLGdFBn71ObxcV?= =?us-ascii?Q?ttivzQxNyR59PvH1hsL0ixXNfhjex0TbZupuZndwT8OzUijPtB/DZdu192pW?= =?us-ascii?Q?4ewD24V2lxRCPOieoDg0ESdWI/QU8QuYuFyN9eR53PwUMJD5rcaS3Y+4zcQT?= =?us-ascii?Q?QldV9d7gYtZnkB5n6qla9jvcD+SMFFqO44EmsWkBqzr4MT3Cp30Lr6UsN+6E?= =?us-ascii?Q?mZvxZA53BmWXUpAw9x+fv6Oi8/EZZJ3MmeQ0BGeYAaRv3fa7HCtcR38spG9F?= =?us-ascii?Q?t+nxHdg8bsfs3a7REuHhDZ57fDW+WMJjm0VjU90mbW7AUsMI6ymorC6GCCTS?= =?us-ascii?Q?VaUMOPzbpCaHKm7B4PrXR5qVIybUDMIbcMUoW3cfvA84QFCOmG5Hl8uQievf?= =?us-ascii?Q?wezcZmpeL9d5DsZ6/GdoCdLQUkZ9lHHYsEUfB8owlZEZi8EIW6XD5bE6Cs3v?= =?us-ascii?Q?Ik0N2Hnv34l7Ue4UEFGTrHvA2BVlvKisR2X8M4iFrwefA8H3t/EkJBrBrgGW?= =?us-ascii?Q?YQmsxXuce41cf5e7wfNjhm5o66bUFF08se21MagKHMithumDFSqIr8BDl4YH?= =?us-ascii?Q?wbvSy4EtTw5SQH13oBu13Da318eZ9qxM3dDp724I?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: f6cdcc11-9406-4619-649e-08ddadf2c2ef X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Jun 2025 23:00:32.5218 (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: kETUP2y0nRf7zJfOZ2CLePnCon65hwkSklraZXutB1OiQVmVeiKWIS8otbF3n+qE X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9141 On Tue, Jun 17, 2025 at 04:01:11PM -0400, Peter Xu wrote: > > So what is VFIO doing that requires CONFIG_ARCH_SUPPORTS_HUGE_PFNMAP? > > It's the fallback part for vfio device, not vfio_pci device. vfio_pci > device doesn't need this special treatment after moving to the new helper > because that hides everything. vfio_device still needs it. > > So, we have two ops that need to be touched to support this: > > vfio_device_fops > vfio_pci_ops > > For the 1st one's vfio_device_fops.get_unmapped_area(), it'll need its own > fallback which must be mm_get_unmapped_area() to keep the old behavior, and > that was defined only if CONFIG_MMU. OK, CONFIG_MMU makes a little bit of sense > IOW, if one day file_operations.get_unmapped_area() would allow some other > retval to be able to fallback to the default (mm_get_unmapped_area()), then > we don't need this special ifdef. But now it's not ready for that.. That can't be fixed with a config, the logic in vfio_device_fops has to be if (!device->ops->get_unmapped_area() return .. do_default thing.. return device->ops->get_unmapped() Has nothing to do with CONFIG_ARCH_SUPPORTS_HUGE_PFNMAP, there are more device->ops that just PCI. If you do the API with an align/order argument then the default behavior should happen when passing PAGE_SIZE. Jason