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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?QNTxqaVGNJwsL1FrclPiQlisSENZ8tveunxTyTytz5IZe5NwQ9aT8vIpgQzZ?= =?us-ascii?Q?KvrbW9ongzEWrBVO/f0ud6j9ra00nJE44OABQxD32Ty40zfdxjvW0nlnKmV1?= =?us-ascii?Q?ZkDklqnaFgXnAxlSk/U0e3AmlSumB7tNIHd20TgQwsjj/Ub97gIRZqkNXoM/?= =?us-ascii?Q?BrEWCuEVMY1/WkoOE+sePSzIKQ1Ykwow8hzp3/SKvCXa53x3Zamng5QSApry?= =?us-ascii?Q?NWbrRbRmespCbSoBKj6diOqVst1ZbtaqwQM6CyC25gXnUExyqBxxaPsJebXg?= =?us-ascii?Q?yoSSOa3WToZ/qQshQJZyb54kho6YRJvPhVTH2hxh8grl3q++JzBaNQ0Chqvr?= =?us-ascii?Q?5u97oAkKxbiAfqEAdTCSGKSZv8KoxHHLCJJ5OxRlBElDjccjDCaLoxVFJ3BU?= =?us-ascii?Q?X1O1zGMwW7L+pvOOSdMsrTIePrJDk0DdbjV9pf6uQ+tzfXKEAJR3Ws3ZNDUZ?= =?us-ascii?Q?55eJwn3b4Ido78RUYd2XlB/fdV9BhVJn5j+Lyj8rDUCH1MTrLOlfny+AaAO8?= =?us-ascii?Q?cXKDr/kjQQjmz1ygqWRxrV8w3LcIvauVoDT67r58rkO/4q3/2sFm2lLUluFX?= =?us-ascii?Q?c1AsaHiJSMp7Ck/WDHZbJrypREhStTF0wIzGfy0yDgxC2xsiRakl0KFzZtJA?= =?us-ascii?Q?YUfAqVFGiDg/BlwBHNTTU8sBWIZ/CPCSLt2IvO1QA3tIQMSHPI0J8sNWKE+X?= =?us-ascii?Q?1t+GI1YvLYLMJ+3EkONmNu1QJsnycuI4xTH5NOn2YBzSCshV4sMCvahoOUt7?= =?us-ascii?Q?otJepVnxNGbD8S3wtJgUWiRxQ5KP7uLY9giWPdrsfiE7IO7/VTprXYRxL7PL?= =?us-ascii?Q?iWr6OShh419SCW8cqwTnMW9dYXeCYoU704OgZ3Yt8JKloFkA8nw+RZH3MQxD?= =?us-ascii?Q?90DqK2oKn3g2xTqAJ1ttXIs/7sOvJunUo1StzdoV6qc9uDphfEcWd/MzJ5OB?= =?us-ascii?Q?Z2ynkoZAr9dLyny4GB7P1T73YK+AJbORT4Jq7nxroWbXpF+7+oP0uZAVmXSO?= =?us-ascii?Q?gU2RChnE7VrLmchQNUDGxGV8V9AyY9Tl1yS/qS5v1PX+dr6YCW4jKqxKS/DV?= =?us-ascii?Q?uHRRCPoRgCCojEudPbwlLr7bPz6JXdH1uJOBYDzq1QtXM98v3X9EtX5nEkDK?= =?us-ascii?Q?j7LCZiWSd1eui65bO/+57h3ZVFgGo41wDMoGKK3dTDOKfRx/KFd7LoRt0X5o?= =?us-ascii?Q?eiUfHfqCVXMI6abhQEQEK5w6NH4lAnXY6zpTuJrYvjBQWAS7wNggXDsJ2Th6?= =?us-ascii?Q?V8k9YfpOfX/+a5P6kUlsdBJ+FjWTvfCqwMTzE7HEY3R7wptpepiH86GyFfdo?= =?us-ascii?Q?Zvl6rUI5jUu+V89BBH2pk2+wL6d9NAGBuJ4u8fMBvq6REilGPquwn/qHPzOB?= =?us-ascii?Q?fXp0Mv40WJ9Oam2dePHvtXnPvdi3/ozmvIp3yUNNFTMqifLvHE61b44c3rAc?= =?us-ascii?Q?d5vA2KB/JIWN/7pabqJI8qaT3sEBxuGCtmy8T9RjwRV2v8VTGLgP259WL0xa?= =?us-ascii?Q?Zce8cz9uXSMqMZKTAINCeVVzcOhFrkDXFv8wjhtTZj2Fa25MefXiPjZA3hEr?= =?us-ascii?Q?OvmltpKlhMArqilgT0slGG4CpCrihTvC5F7TMme9?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 54c3d18f-7ee4-4c1e-bc79-08dc5e3daef8 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB3849.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Apr 2024 17:50:20.2566 (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: PKgUIEL6Dy7yALb8DWdMwCpmB+86ulMzqyNOd3RKPggiootW/Bt0u+VqQOz8QFpy X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR12MB6313 On Tue, Apr 16, 2024 at 08:38:50AM +0000, Tian, Kevin wrote: > > From: Liu, Yi L > > Sent: Friday, April 12, 2024 4:21 PM > > > > A userspace VMM is supposed to get the details of the device's PASID > > capability > > and assemble a virtual PASID capability in a proper offset in the virtual PCI > > configuration space. While it is still an open on how to get the available > > offsets. Devices may have hidden bits that are not in the PCI cap chain. For > > now, there are two options to get the available offsets.[2] > > > > - Report the available offsets via ioctl. This requires device-specific logic > > to provide available offsets. e.g., vfio-pci variant driver. Or may the device > > provide the available offset by DVSEC. > > - Store the available offsets in a static table in userspace VMM. VMM gets the > > empty offsets from this table. > > > > I'm not a fan of requesting a variant driver for every PASID-capable > VF just for the purpose of reporting a free range in the PCI config space. > > It's easier to do that quirk in userspace. > > But I like Alex's original comment that at least for PF there is no reason > to hide the offset. there could be a flag+field to communicate it. or > if there will be a new variant VF driver for other purposes e.g. migration > it can certainly fill the field too. Yes, since this has been such a sticking point can we get a clean series that just enables it for PF and then come with a solution for VF? Jason