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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?INqPXvS2N09h+R491eTBjRTWgI7go9y9qjmyjmcJaOG+b7eKHjlxY09uJgpq?= =?us-ascii?Q?KrSju7QwLc/F6LE6ZwpJttlmONJLnjrN/WuPaw/0Omb/y8xasU/HFvtSN/Gg?= =?us-ascii?Q?a+jV5ksnrl1/RJSt5lKSUukjZFShUZtKWHF5R7DyufyqYfaXi+RE7LmjEmSC?= =?us-ascii?Q?1BCjr6t2sBY9dPrSsSINMhKL4PPVvYaJbPLrrLuW4ek0OEIHvSvBFLw7prKI?= =?us-ascii?Q?9+AZVQfyV2uq4FKPOQCcNAY8nRp0QCDrlAiyZvTY3G9H93e921d+4sOBpwbH?= =?us-ascii?Q?QmI7bAD8K5Q6caeoYbS4boURg1Anp48OkqYLNQSMJUNVlUk2BYviE+TwNOXM?= =?us-ascii?Q?EEIzq2dj69yGiA/RQs6z3how/g0SjMrfk6uUQZlNqomd4rsdPwehdrLaI8cf?= =?us-ascii?Q?SBFogxFe0MY9p7z57a44si8pYfpxyV/et6mHLouaNiAFZlZniQ9xfhVkF2gb?= =?us-ascii?Q?XSa33WIJpZo/li14tHm8jEYSG11OlkToiOiMqlq5Lkr4Dm9Azd8cdZf9nQUM?= =?us-ascii?Q?EzoXR2fCD2dlNNnCnzLbHE42ZxEL2mzAech/PLANkneyh/AMeHb5/AbvLtyv?= =?us-ascii?Q?QCEpPpcsLHLtkiFyqDGxViKDCQ5V/yemcHz5H4OjGNWB/sGBXmJbG1rTAAYX?= =?us-ascii?Q?iDH2JCrsjeatz1mzif9eIFMgpgYIh1DF2+nSkykHWYMHahRV4aQc3cPBZYzf?= =?us-ascii?Q?z1Fg5l7vYjnxyNkKljgp7NQ+21WJNGPPUAqL6zSBF7Cxoyqao1joxsmSAs5i?= =?us-ascii?Q?Ls1GSpE25kTZ4obLk1h5kx0s5wcAUiT+kZDyXI3cLCKy49O59m73opKS/i+C?= =?us-ascii?Q?43BJ6VEVkgC/7aFvXswZ8EyWij8lJMlfqGN/HQfgOYa/8iukrW8sTji6Woln?= =?us-ascii?Q?DFE9BSj/UNIZVN4yKMc7tKSTOkXgv1hYQcCa12dYu3dXQx1wKMAPlXEN8BHm?= =?us-ascii?Q?m2wzQOiIzGhgevc+WCL/z2sGiXJy4quGqwV+r3gEkyxfW4Lz0e+Y9h8Z++3M?= =?us-ascii?Q?Gc3b173MhOkU7CKFIqDAm/z5x05mDHWJPDQ30ELEJKTOEQV6DiTtBs6P/NjB?= =?us-ascii?Q?6mkIFv8TNtizuuOKvSqx/QKqeDIbCIrJaAFjf7uIG10HtWnJYzToFwZq1OHy?= =?us-ascii?Q?hnGM9yZqx3uj6sG9vrt3kYuANMPby6Mf893Qhs6U8I1H03KwKblNeJiwLPiF?= =?us-ascii?Q?fFzHe3hhEKLoJOg+SKHj5AxjALqkZyt5Mq5uiMB84ME2DqXRoptx8U1MrOEM?= =?us-ascii?Q?n1Cbra/8jF38EDdZreM3KF4eNI9U0nLYaJ6UhjvBO9r/r4+xqUFNJZe/dyM7?= =?us-ascii?Q?BEcZ0ZgYffGxGkS7Ke0Ym9At09BbgMj9Rww0jl5qCn6XXIaCgbzCaDS4ZjEU?= =?us-ascii?Q?X9oFtHYwMRwjomwlYVhgftdSqLLe5C/BCPEdvjk8xT7BwWPibh/HxvzJDUnX?= =?us-ascii?Q?kefapopHBC0nlvMJ8i8UTBcLeBdzgY33dedpAnTjoIWR5KcPgWRdoZM5liS0?= =?us-ascii?Q?EQBP3F9NMEHUfWxRniX/5691oWY5pJ3/P/cRF9nnYx7a4iraMHf2TmVpDjro?= =?us-ascii?Q?zuklCcrrbiX+yRmY0bSsh+9lAP4Qm6amReBO5QEC?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 896c6e5f-5217-43c2-449a-08da919cbcce X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Sep 2022 13:19:19.6781 (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: 2fqMD9GvMEp5z5jhirUHuifz2wfMK3rzF9EIt7tPx9nsdKU2RgVtqy/mBrn7ZQTO X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV2PR12MB5871 On Thu, Sep 08, 2022 at 01:53:50PM +0100, Robin Murphy wrote: > On 2022-09-08 13:20, Joerg Roedel wrote: > > On Wed, Sep 07, 2022 at 01:52:18PM -0300, Jason Gunthorpe wrote: > > > Why can an identity map be attached to the RID in v2, but not a full > > > translation? It seems like a very strange design that entering PASID > > > mode completely breaks RID support. > > > > The reason is that AMD IOMMUs do two-level translation, which means that > > the addresses in the PASID page-tables are translated via the v1 > > page-table again. In order to be able to use Linux page-tables for PASID > > mappings the v1 page-table needs to be identity mapped. > > Ah, and without a default PASID, RID traffic goes straight into the second > level? That actually sounds much the same as what SMMUv3's S1DSS can do - > seems I misremembered yesterday, we *could* in fact twiddle that to handle > identity default domains, it's attaching a PASID to an identity domain that > remains impossible without installing a full 1:1 pagetable, my bad. What is the use case for having PASID nested under another level of translation? Jason