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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?lAKFxgDvTGmGlG1tkj/6Bhjonb2+FvnEfqzM+YbUDtBuz/kkMIr0vUrbyQ79?= =?us-ascii?Q?Gq6xWbcJaIl3y6PYrzd+AJW1ZBQi1AQfq5W+8AQIuY/zw1A8ySqGZrzj9qzt?= =?us-ascii?Q?8af4xntNVEXsd3wAp+0Grz6DQjlJxB/d+FF/fecWDxpHmuL3X3uu5gHh3juX?= =?us-ascii?Q?dKqbcEQqij3QgCK7jva9p+XUczDRTecS3k2UnvI+xPLRoQJwN7gfX8+0svKp?= =?us-ascii?Q?0ZMJVDRcOGhmjU408XWUJZ9THGv5SV+vUoSdI7YfKbyhzb9yMHvX46v5viwX?= =?us-ascii?Q?kKJCd2qhwkPr0Gft/pzH/QvkvjJyyi89MOdj2gCRHytwhRz4G5eGyIL3Vm5b?= =?us-ascii?Q?lNfiXBCZkRJDkTmmALNuazvWcPcw5XSQJBMgwi7KAmIeft8cplkF9EREoIGH?= =?us-ascii?Q?oWI5c85klcu1nmUJNTovCh3d21w5GbhySQ0L0QVrljSvI3QoyTuVuugNE5J4?= =?us-ascii?Q?xM67HzmyafT70odUbd8UDVdHYtqU03zAhRKAJKp3/DnJVGZXRxbSodTcS8E/?= =?us-ascii?Q?HywJKB6Anhc+IragBhrYiMX7laXbErNi0Czv0xd2ow1My6rZ0mQEZd+u1ayl?= =?us-ascii?Q?HU91BZlui1kCnq2WD41KhojKS/ehf08MhG7Tc4JkhmtJZnzcxTN8C3zIr7pB?= =?us-ascii?Q?VeNhg0wpD47Jom67b6/crFVYstOz/CsbKU3luoLhQ0cOgbae2+uLnoEDiWXN?= =?us-ascii?Q?d/rkByV48sUPhiSHCFyUDcWZfKVWgIcIOHcppskCwOlhxTj/vZKNwkCtKbyy?= =?us-ascii?Q?AIYh29lIIw4jyHNnalRlnkWcDRvQJB0WQ3a+GzizUvoYbyLmySD/i8S0O2e6?= =?us-ascii?Q?AMGskdf3ACUj6RZGNqJgmhfSLjp6ec0PpjpmRAxnWjCgAURpupG4e5y8fGVH?= =?us-ascii?Q?cWsJ2RKgGKyRNCPhiNyLUHSm5thk7/a793HdU3w2+GbOlu7Wan6sW8UEhY0+?= =?us-ascii?Q?zmRKIWukVnbAL5IZJLNyIkdwc9vvsPKT4UZrHDlwXMZT7ZgdqZ8AWtxxP5tl?= =?us-ascii?Q?LIhc8hwRG1vkIwAg2Ot5uaV3BueR6SYxfTDB+B+A17VeM6KwMDPOziXz+3iF?= =?us-ascii?Q?7A/iNFXdeFu3C1pqkuqBvBQ6lg1U4Ncbo2HGsSrS8OkeBHUGO5P0kbdkVgz8?= =?us-ascii?Q?ocBTk9D+kI1RqE37G9d5YXHglk9z02099DSr2APQHehxygiMqL+NfRJF4e2U?= =?us-ascii?Q?Na3UI7byYJhyZ1AfjFBmuaBDI79J8p0eBuzT7M0Fro6bEVT3X4R7PoLE1PyW?= =?us-ascii?Q?VsZHJBVQha2LE1IcHLjDCiEps3EGSB2O9aCMoQMgkvOe420c0xzGqJuMkKcy?= =?us-ascii?Q?dLRLSK25rL/KbeQ4E0bElAa0?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1a03220f-67e6-4d4a-1baa-08d989862107 X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB5506.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Oct 2021 11:32:22.4204 (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: tb9QBRdgOP9RxpuYab4kgp/H5n3Fmu2zFIp8eURY6MDkOKNmAAZ1JCIcZN+AIHuX X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5288 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 07, 2021 at 06:43:33PM +1300, Barry Song wrote: > So do we have a case where devices can directly access the kernel's data > structure such as a list/graph/tree with pointers to a kernel virtual address? > then devices don't need to translate the address of pointers in a structure. > I assume this is one of the most useful features userspace SVA can provide. AFIACT that is the only good case for KVA, but it is also completely against the endianess, word size and DMA portability design of the kernel. Going there requires some new set of portable APIs for gobally coherent KVA dma. Jason