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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?9BUEj3+AQJUuaxgkVh4yn5cJiqVa54Jod7qMRcDdbYM3+p7qcTPsNVoaqZwi?= =?us-ascii?Q?lBt/xHOVDb2HQ1MRVGap/XznPPvMBaJGvbwVjABhniaQfFG4lkdIhbm41g+c?= =?us-ascii?Q?3xkfYQPSnBa2QrNA8o7T1xHNKbxuTZr37P3KvvICOgm6YmiiW3jQc+280E//?= =?us-ascii?Q?4O1RBVwaNDPfNJS2gTPt7zlvJ89diwP48cqMgFpRY8yKqoJYaPt0dRTUoI/v?= =?us-ascii?Q?BhKOjvS+y5kAixIrJIpKnVm/pW6/HWAleTZpovBAso4bTaTMS0aLIoRsgWmW?= =?us-ascii?Q?4m02IrBZD2DCCkXKucGxyNIKiEgogCzsxEgsSKqwloIUUTupb7fqdM7W25Mi?= =?us-ascii?Q?yWWyrB3hJ0hOPUBsaVK6FCQd9oJBHj8ZjcL4sKyfr0z0DxoIUua5LaJo9Crq?= =?us-ascii?Q?Ua84DoTEliBsPBZZCQNRrmT5AWTFcXwYs7oFRk7K/aej0/odZC+Uny07VFMg?= =?us-ascii?Q?3zRt8P6/AXwvQ+LNhgid6/ceU9fSIh6TSITdLrpWsZjj1J70SgwV23VWKvuI?= =?us-ascii?Q?udoytXMrAOPta7sTLgCxDnOeFSOFIsq+dqLQn6z9ifmtce43qNRmzcNO1FYn?= =?us-ascii?Q?qQKoR4qtU+3U0+14MoveICYn0RuIxzCS/0e4Imhd58xBGqxoTWp815ve+fu2?= =?us-ascii?Q?f6Hpe18y8Mm8d1W+43Nz238Ui6dfBAkarQc3KZiDvAQnhNQItOpISMRmyYSc?= =?us-ascii?Q?xLSRb+S/K2cE6T5JU3XOX6A4otKYPY045uxPsIUuPPTaQDOjDVHdyZvsfnDZ?= =?us-ascii?Q?L6OOL+LEXPDM3NGltuVPZhVdzWRnMQ+hkRo7Uz/rQd8kGzjUiLAVDQNevo5J?= =?us-ascii?Q?K8z7WJjreUYeB0loARuKMghX65FtDRPhThtJf2URWFMbQPz2jhOHKhLmWSWE?= =?us-ascii?Q?pYtMAYTpjoL+MyvogMgGJJ46t57+IMxx+YsJdLGv8GPV3UJlALXOeIIcNt1W?= =?us-ascii?Q?A3uJ1PMrp7O0Lyiy7dQCPIEI8Nu9PcHtDshvNE7FshSENS3aFhnM0iX9L98N?= =?us-ascii?Q?te06ZQU3vx6YSTakj542T2mWRby40+ChRjcyIWP2eWPBZNU6WLcmVWW4abnD?= =?us-ascii?Q?OQu7AoLb+/9TRC8xXZ9HBcbWj5XchZQmT5L3fzuMknP81dpTJ36t0Ljepya7?= =?us-ascii?Q?rUAQ6P06dIV4U1fKFaDhZ13MugdZudUG3i2fXHo236tMrN+HKsqsSIDJ/SGb?= =?us-ascii?Q?Y/BDFQg1jXX9H7Glhuru+6wex67ElyAyYfGMIHELcokCmI9Ylqxe4JfxCn0A?= =?us-ascii?Q?5g1r6Him5Nld1RIv20h+kLRP4GXx2BrFEFOZHRKcpR9L1EetI0TJ6fA1Lmtv?= =?us-ascii?Q?rOTVyfIMX0Chmfn5ls/qDMkiJMY/E2nviPijB/ykQrhcECHeRfAxGkIVU4CP?= =?us-ascii?Q?B494nVxDKaOuN/sEzc/YV5R3fF3OHRsG44A9ejuTjIWU1V8D6D5DFNlNQgoo?= =?us-ascii?Q?KLt4e12he+iq8RVUFOMm2K6da967FC2Dgw/xaKtXCc0pH8v1Uw2myevLgPa3?= =?us-ascii?Q?8jr7/EaofPa2NTwOo0bcPJsCkjG9RfkFAqoSUfKQqR720ZZ9h7nx/0TSbMbx?= =?us-ascii?Q?/4Mc35l5e0C7Y88Qd0p42lx4Q10hw3f7b2p6b+8A7g0p3lZ4M/Ome07VwbeH?= =?us-ascii?Q?qU4SiQDr+SPYs6huBG1+5EjuO5+nFKIFJ8p0h7hbUAs8ZPn3PY5PqmrrWBTA?= =?us-ascii?Q?ZZAnhZI296Vri0xioe/u0zJY3CDC7z4JD6JlQ6g2vmfNhGIk?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c34f0b8c-6bea-4488-5040-08df038fa26f X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Aug 2026 16:32:35.1770 (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: oa8E4iv6RtF8CZBG9OiZiAHfNlTsH+aP+RESeIGdNxi0A60u59VivW79OvdfOEp2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN7PPF0D942FA9A On Wed, Aug 26, 2026 at 10:23:20AM +0200, Andrew Jones wrote: > RISC-V uses the same basic model as x86 (an IOMMU-owned interrupt > remapping IRQ domain). x86 makes that domain per-IOMMU because its IRTE > resources belong to the IOMMU instance. RISC-V makes it per-device because > its callbacks operate on the device's attached IOMMU domain and preserve > that device's existing MSI parent. The IRQ callbacks provide the lifecycle > hooks, even though the mappings, MSI table, and device context all remain > IOMMU state. The irq domain isn't per device, it is per msi table, many devices can share the same table, and the VM should have a single shared table across all devices. That's the core uniquely RISCV wrinkle I think. IDK how Thomas would like to model this, but you will get a better result if it is very clearly explained and asked. I would like to keep the iommu out of it, so I prefer if IRQ code patches in its MSI table pointer broadly the same way AMD does. Though AMD doesn't have the restriction that remapping only works with a S2 domain :( Jason