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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?QWHLMy5pDCxZze794/mGncM7mipI36BPmVbAQSOhEtzV69iOLrs4M/e+Yl4G?= =?us-ascii?Q?BcvgeaiQbG6ZKjVCSwzfaumkBA9/x+Y43x+vC9X1p36U7yXTO8EAPD2RPN8w?= =?us-ascii?Q?s92VP/FgKZoH9QCGof9sNF3zjrZmAZ7n/FK93W9Ki3CmOXq9VsjfdjCr3B6T?= =?us-ascii?Q?RTJSt3KIWstXq4UmE47IFiummNxAZJzhSTpXmDAYZ4o0sWJtasrChfoNqa9s?= =?us-ascii?Q?Be+/7UNv03/PiO7i/y2d7sVVXaLm7jXYCj04FxU8r9LQQZnrBE5gM7wXC/rS?= =?us-ascii?Q?0iEeQCCXicVw68xeSApR6dKzZ7X/Z9liFFiYAPTKWjJ7RxJdAe/tHtZnyGgw?= =?us-ascii?Q?J3V8aeI8rCx9zqUx1wjTt8ZYrulBRycJZ/ZUrD5Wv0iO6DuT0Q5ZIbqBFpIY?= =?us-ascii?Q?muW7nBcHnRRschoTcI65+0FryQbvdkx68b0zKKOWXibU+BwHwlj5sOEUKqHp?= =?us-ascii?Q?uM9VB25x2UabWeZ7IAXVuxv/5wKsdKLfPXd0ddjG2tpsiEpE+603E+3b3RGL?= =?us-ascii?Q?SyFrKIrtNG65+NzBk61Ymk7eytpQIYuoEQFCYnf9sjZ10hd161M+1hjJSxTi?= =?us-ascii?Q?5UsslMIKNpMqgyR8j6o1ziRFrbbeU4xeOTN+bGr79ZXe+IWL7BqV/S5Jn/HE?= =?us-ascii?Q?+8gH0crOtvR92/koLMJWGEw4MknxFtZwc5FcgsbJS7i0cWHsPtdIQxWRZ+0f?= =?us-ascii?Q?PXpFd5kzvtCFslgphtEGyU665qnUfvw7UFAZOVqcqsv6MGezcBXo3dmg8LWe?= =?us-ascii?Q?A76KyU1KyBSZt5VCZ2xHZuSoKA7WwfRyK4VWQ6DJf4IExOAVeAZ2Mzyi0HYl?= =?us-ascii?Q?oh0FrsQBA1iUsvysdL5XCYxTDuQrJvu+gIVMk2jtgrUcgW+nK4TLfhKwnjjE?= =?us-ascii?Q?os+oIWEl/lpd22gMJmUpfi4ZeJlfJU/Z0jpifaojuUjimQREjxZhi+PrsMds?= =?us-ascii?Q?AXaC0vr0I5VHysSwGwilwl9JDz7zY/1kZskqi5lW+N23OvoxX+mtejUQVl4p?= =?us-ascii?Q?irLFkCRWZUrM62YobCUSfKTXjZNGO3jRk8z4dznTqTQBga/aEPfb2+RFFGfW?= =?us-ascii?Q?PrlcrNuRextKnoma2Zyr5bsMzr0DsfPe1Dw5VGclnIYDlj4uZT45QfRXXZGG?= =?us-ascii?Q?nL7D5h2cvQCzZyPdj/zwNnW/imFxMLHdg3hB4qZ7gyRsw6/CTsXGZP6oQysN?= =?us-ascii?Q?MyTxI5UBmbHO+NGTkrBdEzTSyVeIhnl/Hjo5ep694dDJyktVdJk1/5zu9I6W?= =?us-ascii?Q?hPUTBMTcF8dQU+Q8EFsxFDL4mb7mA643XE+rh6VLNRr86tgO4ELobMa0HZdk?= =?us-ascii?Q?KyhZfvlwI12pxJoz7vCOkNrbF4jqKC2l9Nif65hfN1JFUeMXJXM5FR7dOqjz?= =?us-ascii?Q?02rE7jvZargbCKjp0/LXLhQyxduum7sKquQDeKT8L5z0o3CZSrrgW/3+o6TC?= =?us-ascii?Q?WozNGaEG9AlBYOVpdeNvMS9mm2IKQ7ccAppCAcZE8prxZ3kaTaEkpd3oO0/r?= =?us-ascii?Q?HlY8y5oo6o3ejYMJDImu1cMucfexnXQy0eWxQfz/GKgHmSgLAF7qYa3tsbja?= =?us-ascii?Q?QNglCGIkjQ6WZ9/0hvfpEgM2oCqjAMXegRMcp2ho?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 37933b1c-09cf-46a2-3c02-08db1be96785 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Mar 2023 13:15:48.3202 (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: YQ1SvejwGmf4XvrUSHIIJiSUZynGj4uPUx2K7vxKcjNCmoV2SJnbEFok+Md1hNfL X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB7334 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Fri, Mar 03, 2023 at 05:57:41PM +0800, Baolu Lu wrote: > On 2023/3/3 17:32, Jean-Philippe Brucker wrote: > > > I suppose the common thing is reserving some kind of special PASIDs. > > Are you planning to use RID_PASID != 0 in VT-d? Otherwise we could just > > communicate min_pasid from the IOMMU driver the same way we do max_pasid. > > > > Otherwise I guess re-introduce a lighter ioasid_alloc() that the IOMMU > > driver calls to reserve PASID0/RID_PASID. > > Yes. We probably will use a non-zero RID_PASID in the future. An > interface to reserve (or allocate) a PASID from iommu_global_pasid_ida > should work then. Just allowing the driver to store XA_ZERO_ENTRY would be fine Jason