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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?RbyNzpgHf4nBHZ0rmqq+8dp14yfsOCAN5A7BbBVb5oQlZ7TXCyBFWTdOPcTi?= =?us-ascii?Q?CrYGMD9L5tqjTjkrHytRKYwJ7MEUs6qJR0S/Zt+klnlVn9WBYvOGbQHYA9zq?= =?us-ascii?Q?L78MUywrzWMdFcwOerjNMU2h3RjWFp/1ht9FYILCLCVx4J8Qi6BLoc3J6uzj?= =?us-ascii?Q?4iro8pTblpcxnouP3i8Mp76GV4vTzP0xWjmlv9MPHPgPv45wV8/jsdvJ1BqB?= =?us-ascii?Q?asCk2zcD38m1iYq+dZYsjJ1CzxGkoPNB3MVdsZmwXJDt1NdE4o+2JRkUdDHR?= =?us-ascii?Q?LPApyRdwCiO2dqS2lgRrmybPgCJjb3XsXMU1k2uLoMezGomniqPFRNRYhiRN?= =?us-ascii?Q?olnyZeHNcszv6F9sOt/tOowVjwHXdwoU3MCIERucwoqRn8FPjrAalY7aIxG7?= =?us-ascii?Q?dsKdZmv+zjsDm8t/3e501gvN6RUR5rKgZCM4MByhOaKbuLIsmRCPzHWkG4Mj?= =?us-ascii?Q?kyRoT4QVNDoF9EDdXJy3uPU8RvIjq1tM+17eUxjrccQWgJlrx2dsnL7LBUrM?= =?us-ascii?Q?QYccQO2m+9weSyTzd1xbbQ7KE92HV2It5Y3yDK0rIRUUD+xNIgRNBXXb5plp?= =?us-ascii?Q?FF/gp1gF41g0EtBeMm57BM00EWOkrxM6WWTggbFaZtwNMkBELeJLEqOE+eWB?= =?us-ascii?Q?/I0sqVj9Ufkn3YY6f6RA8zqKXg6WzoWs8PeVPzeRcW3I0BUxMCqun9CH2HBi?= =?us-ascii?Q?ce5i5eZb6l82RdXp/3N8/OvlmK11CCZM+HpUyybqV3Tu6OLd8OIlZ9FWROCB?= =?us-ascii?Q?6m6pMQwKsYe7O78DkDGfX1DKaF2EdiY5/tmLvrG/8cAkLE2SPd/AAgyXI2OU?= =?us-ascii?Q?Z+jd2lXpwPYZekQlhDCjjfFTP5R8qnxiL7yW8RK7DYz4KS2bo0gcvLWiVbeQ?= =?us-ascii?Q?b0YkRMS98C50RMzi2bk6qcFqBvKpOqQQg0yBv7Rjwe8A7K6QeW/k+2BC7Dpb?= =?us-ascii?Q?hqU+x0xsAwtSwQA27pFhchGpVa1qDKEFaIpnOzcnu4nvUSUcdQoVHAT1BVOl?= =?us-ascii?Q?4R1CM32x+fJYLe4vMvbBmLOnGEEDA9P46ByUs00EMLGwkZQEMqKooj/ErcQu?= =?us-ascii?Q?Kn1vl8rvugFy2G3N39LoAHh7lQSi/DUqxemP7fT/bp8FwheR0efQAzyiSkmh?= =?us-ascii?Q?Q09EZjyIO7nclvrc+w5wUkSXI766nFaJUW9vXPaR/tJPsBLS2KFOp86AFzNt?= =?us-ascii?Q?TiEqCMaFpIidHLPofWcde6LeOTBJ/TK8TSpWo58KjNoAizzhfAd2dXuG1X/Z?= =?us-ascii?Q?WK/zYwz9Go9IAK1+4ZTuD9C8PUEWjZShkUJnEczVdroqlWzjq138g3sIT8tm?= =?us-ascii?Q?WEFzQ3YGZI4nL7CCEnu1G6sdVnwnITWXi6b18zyQPFsiagilw3YiE1IoH0jN?= =?us-ascii?Q?oTlKwXmlRdIOpJbdOekjc5Bm/wU7ZvgMNN1Ln+8n/8Y36NToP+2h7fLujjHj?= =?us-ascii?Q?qGKNYJkVpZcrykrYCVwZTlaM737Ach8nmAQ8Z84QyW2UNcnFQy6OXQMFZR3Q?= =?us-ascii?Q?TvSgu8hjUCUwE59zSCM9y3Z1bx2kgvkN/M37P2uZU3fuTyjQwEzSxzBwJeBz?= =?us-ascii?Q?yOc9ZBo524xv69aFddCRpaMNKHv0RdQhyUSxBYAaLWl6uRnQugKFjHTRURgP?= =?us-ascii?Q?+DovbPiRd4HphqfdnBSBT5gPBmapPMlP0xR9eXz5cR3vt9G7aC2bKeCVw+5n?= =?us-ascii?Q?5e8ysMQjtiTnZPOvEcdELx9eg9Ws+xNwnkG4g+ao9ETHXanU?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 00731ed5-fd8b-4d9d-cf5d-08df2eb3cb07 X-MS-Exchange-CrossTenant-AuthSource: CHBPR12MB731189.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Oct 2026 14:09:45.1097 (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: b0/fzE02P456IsXRnIUoxWq7jQnhLycnba1Cjf+inB2OpAFE7rqieT3Gsr6Gmouk X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB7978 On Tue, Oct 20, 2026 at 12:51:26PM +0100, Ryan Roberts wrote: > > However.. you still have to affirm which single mm is the mm that the > > device is going to be doing DMA against. The process the opens the fd > > should not be forced to be the mm that it gets linked to. > > What is the mm representing here? Ultimately we want to install the KVM > instance's stage2 pgtables and (pinned) VMID. We currently get that via the > bound KVM instance (which looks like it still works using the cdev interface?) > > The guest will then install the stage1 pgtables and (pinned) ASID associated > with the relevant (guest) mm_struct. > > Do we _need_ an mm association in the host? Ah.. I see, I didn't quite follow that. OK.. Ah everyone else doing this is using iommufd with a viommu to establish their connection between device an KVM. eg Jacob Pan's series. That's a probably a better idea to stay aligned with the common path. Though your reasons are a little different.. If you manage to get pinned VMID out of KVM then we can implement SMMU BTM as well! Jason