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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?UDYLtuyr7h2U2JQuHbB81nUH6NioWCs6aPsqZ+OO1zHBSkMvAhBGlWowyQ4k?= =?us-ascii?Q?ajYWEQN9YpcDCfEr3QmJIPrdtQyu3YM9MltTy6Tk705widlvhAVVCygyjsvF?= =?us-ascii?Q?rHzoxaim0fkJBKMWxN6mu3JmBQz+3tElgo7ZrsvjvoCKDwwg22IwJNlrSSZT?= =?us-ascii?Q?gXXNIhyejKuN7bOEbONQt1iJjNg39SDV9kHz2IMDR1iRnor5rl8I6b8fYxOB?= =?us-ascii?Q?LmgfNHVSTxrsJmMHsdFhxhBWgPOM9ERnllLVBPgYy4+Zc5UJmaddogy7f2pV?= =?us-ascii?Q?GyvncdG7FC1TAEE8a2RQH5xCLCwTlPUVJ/oaUozvjn7Piqa5wt9Qfby5qbtx?= =?us-ascii?Q?0pcqVZaNNb76budBVxroU+FJ+gXKASqqMizTCVhatdfwC1bOKCJJFx3shDwn?= =?us-ascii?Q?E4p7wEbXjOTEWiH4eC0jSivVfOzm4EubAC4NjvR/SF23wq+YwizO6A8f4dIh?= =?us-ascii?Q?I1ABJ/PW/77fDADtQcdyfdihOU7i+IOx6hGp35GLu85OZkbVwS24hXWsrqIX?= =?us-ascii?Q?pjEWPcznHQpAb3IdHZ+zrb0jVUKGs5q96I5qiY64ztynmENRxaVsMFi6QgRM?= =?us-ascii?Q?zVT2tA8b0WURv/lrycCwQrnpwifIJ/q2iDbi6SnUUzoqzOtujwhPeLQwNcuN?= =?us-ascii?Q?EyV4yTxitCqJuOQ968C6xy+nDszT5HivYoAYZ8PA+f4gemTkEV50aNvIQizX?= =?us-ascii?Q?8pk42P+mo5CcTX4aCwGJf1UNXWIJo8liGHz3uHJU2cslsmZWzRrb17NsNJWG?= =?us-ascii?Q?HKV+T7vPVJDQIiPZjvHh1O/3LTV+btPA3ZZXwGJUQzrj7T0xNVnXmvGXiQ9/?= =?us-ascii?Q?v7AfPjAcwk2bI70fr8vTzBMtIF9ej5WFPfRr6iQC9ENePLAF5Dy668j737Pk?= =?us-ascii?Q?ZR5OuhfW+YFpUdSlWUvxt1PUpO/mB8w9QYqjOPvluEditYKsLHOTcLc0CSsh?= =?us-ascii?Q?GhYOCUht8ZRnhdqSsSN7tnY1YUtkTr6rAXiOViyT6NZmzna/oOdrdbXwp4ae?= =?us-ascii?Q?H5rpVyaY9xnfxEZSK5egjk1ePMOUXiqimsNph8c2Ucaz/dHIkmULXnB8l9CU?= =?us-ascii?Q?UYhiLVmeCKO2bHKPaP7BpDBtQwgfm/PWnO63aKBwpNISrCoNix6TW5B4Oe73?= =?us-ascii?Q?tCHWyoi+IltsCWTremUequqmk7alZZdri2DkHqNi20KKuFCivQzs0wZCn8WQ?= =?us-ascii?Q?DZz1qSqVDyphrV0E+j6qlF6j8oNjbbsY/qhDhhQho/bd5zzeQFGeCPaxS1EA?= =?us-ascii?Q?bjJeMMRXSPja68sMuCXQB/Ow0yLz90qAD3UdAcdOqcJl4h/Clmf9gxbzk3PK?= =?us-ascii?Q?Y/caoYnxUpE/jTTwdc7ieX9H3+q88d0F2mcy/a7RUz+mxwH6327Q0FESPnUn?= =?us-ascii?Q?bdAaXd1c0P6ZO2zhST2XyCiFt26/q4wrtL48XJm1y4Lw7LvEwrrfUyLODPai?= =?us-ascii?Q?uZRjByVomOlYaOGudYuafP+iAU1qQqem0wYNKyMOEjJH8GYyTLBQxseUO1vP?= =?us-ascii?Q?W2LO/IFPKfwmGxayoXhHgw8uWoirOpFK8bN8I4ys9WVXsSUEbIFFU0G301B0?= =?us-ascii?Q?yVGpmjJN0S5ZxxJXj7HcqXg8vleFqYAg7TkvwUnRF0qd09+wPpwGOdKD0mh4?= =?us-ascii?Q?UuQLLZXN+1Jyk9XkXD+hVW0AJ9PZ7DluQXr55Wiok0cGleV8evfuSaaIvUyh?= =?us-ascii?Q?55jOWpyVIcPWtiPXGI+UOu7ZZxtoV1L+aw9KeFh5lXJOIEQv?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 10e63cbe-62c6-401f-4950-08deff04a329 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Aug 2026 21:47:31.6949 (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: +O0TNKk1j3rv4fx+4GuL9g5qe4uEHmOBoJPGQAFSHo1tQ/Yw5fmD1A5/t1K2QfGA X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB8598 On Thu, Aug 20, 2026 at 11:41:46PM +0200, Andrew Jones wrote: > VFIO and iommufd require IOMMU_CAP_CACHE_COHERENCY because they use > IOMMU_CACHE mappings and have no userspace cache-maintenance path. > > RISC-V page tables preserve physical memory attributes for IOMMU_CACHE > mappings. Svpbmt marks mappings without IOMMU_CACHE as non-cacheable, > but preserving physical attributes cannot make a noncoherent device > path coherent. > > Report the capability only for devices marked DMA coherent. This limits > userspace assignment to paths that can honor cacheable mappings. > > Signed-off-by: Andrew Jones > --- > drivers/iommu/riscv/iommu.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) Reviewed-by: Jason Gunthorpe You can send this outside this series? Jason