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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?DPE5H/xZiwMALJmUtE74mlZdjAA2WZ1ffs9CWDgTQuNkUeYEsA8E6EyubkAb?= =?us-ascii?Q?39rvacl0zCCyiRkiBO/WFgC6DfNHIJ28jHlIsVWRZvcGm9ebQB7n8DfP84hS?= =?us-ascii?Q?Lh3HKgTwZmKd/KhkpfVE/QnKPya3qM54PU7hjQzL95Sv23ZJm+scLPe893Tp?= =?us-ascii?Q?PV4pUnQZwtd++ShSrThx32lMB2bxcaUsUMMvFtzcH/4Avvwymryss0dK8Cdm?= =?us-ascii?Q?TIcPcRrkAhhpB1mcH1qwSY1nXYO7LjS8hHva9fqT8tb0jfHX8qswmbwGtCCy?= =?us-ascii?Q?L58zq1CUxWBxbK7QsZSP428DJ5/khIFICJuqkCVmDefUlMLknDqcJzrn1ZTv?= =?us-ascii?Q?HLV8Qv3dxqu/yaMb4ZluFduAzXzOsG+TAuNQXM9RHc9iEQC1VOE+BfK08uVx?= =?us-ascii?Q?IendOwoRVRwOmtd9fWfQTtPW6CLZXHwBSCLVIFtUncTfV5V3vr9LCTyxyAk6?= =?us-ascii?Q?Cw2UXkP9dBbH2rLQqY1/peBs2CanPqauMzyyDHqcdcbaT+C/vY1yut0ILQep?= =?us-ascii?Q?Zx+t7zZnzm/vKEgB53nMlopbi7fB7X1H/BYjck2HAhCHXGNSm0sbfF9x7x+2?= =?us-ascii?Q?H5aP4satJffuQraoc8bnV346t+IW1fhtgqX3VfEe3eEGwz1qtv0oLeQ1jTvc?= =?us-ascii?Q?uudze6ZKErIpk8jJGfOjp5DYnb2GbDrpMn0f9oGfU3F7R0mWbOUIFzwzyNOy?= =?us-ascii?Q?tAVCNiOS9xII4dw9UwwlydChsVEn+v7uB/XMAqAyKoBZszFQOi8AoZbmd0Qq?= =?us-ascii?Q?hVO6pE9f7hE38vSA6mfTlUwZKcNkFSVfer0YO4Mij9k8GaUYjNxeI384dQQt?= =?us-ascii?Q?vsasa9NgSQ1CZWdwZW7i52oePSWnaOH9RDTvJZ9b+aAN32dDAZnP79AlaSni?= =?us-ascii?Q?GJkAQBW6IkUKsaYyyEqn572G21dayTRf8Z5ElSiAMYw09fNm5ZCuq+NpE+jj?= =?us-ascii?Q?Zj/kLPScFFp9gBgioUun+rbFyu44zcsJD3tAb+STC1Uzg7FytrWuHJfdqZ4l?= =?us-ascii?Q?TFEkc4zTxNn4C8dUFIPquZnJXcLNLC74yj6MOuF8yg2w3AFIqjrAFolh2lxI?= =?us-ascii?Q?kHh4TnRd5RwlMKh5v5q+stHx9tL2nOcowLO+Jn9JtlsZQUY56A9PflPEGlZ2?= =?us-ascii?Q?wVAAisBPVk/dc9uCqndADBsbdpbXR7KQwlbsxJJcStEu2GACM5b6oKZT/a2C?= =?us-ascii?Q?t25KXU7INGUAHqcGtupSvpqzmcGO6ycXe54ENZ3qhSZFRsqpGNX2VMo+Cx/P?= =?us-ascii?Q?tnErNDAgLOcptYHpyad1IosCwc6E1f0TwfP+kCTq3kH14RS8S56SN43DPtVO?= =?us-ascii?Q?Pm9/dcMueY6+4AyopCH9jMYMgkIdJfTeDTxKHuYXTMrnMeljCVrZuPKU2Cw7?= =?us-ascii?Q?w9603qolUAflyKtBedzQO+jWgYT4OTj9Q+Rfdm1KSvsNLp4/7qahEPv0BXRa?= =?us-ascii?Q?hjFznaeDFEYNuaOiubw/kKbzMzjgwtvAg7hP9oFbb9hfIzAEXY0R2FPQTQaq?= =?us-ascii?Q?KKHMQ/CNJvWDzNHwy+osLhF/llW+y7kcEkGI2eNS1QrCDkfFlRBBEGTdTrKy?= =?us-ascii?Q?rVsG5rmhQORjAAzLgrNeLEVNYQNeh0RGOltLjUxd?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 48ee60d1-f036-4f3b-9f5b-08db9367829f X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Aug 2023 14:48:18.7404 (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: kjoFX4brOY8ez1I2a7rTqKiT5S7/A+ld6h5A4LYCI28NOWkLtDSOq03dLVBnDPcI X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB9223 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 24, 2023 at 03:25:32PM -0700, Jacob Pan wrote: > Global PASID can be used beyond SVA. For example, drivers that use > Intel ENQCMD to submit work must use global PASIDs in that PASID > is stored in a per CPU MSR. When such device need to submit work > for in-kernel DMA with PASID, it must allocate PASIDs from the same > global number space to avoid conflict. This is a bit misleading, maybe: == Intel ENQCMD requires a single PASID to be shared between multiple devices, as the PASID is stored in a single MSR register per-process and userspace can use only that one PASID. This means that the PASID allocation for any ENQCMD using device driver must always come from a shared global pool, regardless of what kind of domain the PASID will be used with. Split the code for the global PASID allocator into iommu_alloc/free_global_pasid() so that drivers can attach non-SVA domains to PASIDs as well. == The code looks fine, though I would eventually like to see the SVA code not hardwired to the global allocator too :\ Jason