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X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?XjNCsi3LGcJSh1Qs2Amz//HMjoIxnaodrzJFYYpegWoP6CigFDBy5mg0TaIv?= =?us-ascii?Q?zlfh3Iwszf86vwxqeDfXOPJUfxhNCAPVhMVxCKcxCH9tvClVSg9kEtplAGVL?= =?us-ascii?Q?YhjTulKEpsej9RdaefE213i6+VkRrmqPAhc3vkAyyy6qbjKjFMP91W0+7B5H?= =?us-ascii?Q?Y0YCm9f8K2wVcBBjOKcOXwMsoCAr3sgqm0yAB6O9dgllnnhyJtMydIKQL+DJ?= =?us-ascii?Q?fTHXHM9Y9X0/mJz41lwqJ8wBjRHMhM/AyHdsFBe2xqpk7ooM/CDc45NxrNya?= =?us-ascii?Q?Y3MFhhlDgtEs9XIxdUUu5g1p+nQXJzsMSB57LLo/LflVfYZiCmLlLLst/IGR?= =?us-ascii?Q?hIUbw6QpB5aUPRs8I0AkKEOupZUad4l+VS9kFRmYOToagpwH9Vqh5/EyPgY7?= =?us-ascii?Q?1JJVhTDDElHhTG+yTIf5jP3N95w9h2MOLsijoXc0tgrHGviWq7ga74k6xSin?= =?us-ascii?Q?2wLwmdu5DngOJDfFAf06C1ApjtfABuOAJFO1tJ5bbABrF+4SrK77syXKRAxu?= =?us-ascii?Q?Q1bO/tkl2iNvRcL9zuFDI1ItWEForUWDyKetEPk3OnLgXsQVhit1JWJK+geH?= =?us-ascii?Q?lPvN2WtVdRGm21PaHPbwsC7Sc4if3ILD4BD58wpqWgu6jn5uZFxZaXWPpFM/?= =?us-ascii?Q?wSPWAupYlMnjiHaQKh3tOHK3tqhsBXhsineCObjLqMZ1e1xyYGSLLU2mHWvY?= =?us-ascii?Q?1eXTNkLeVxA0Lv9+f0gtDZn8jwFhGC8IcHrbVxuJvBpfOdw6atQBjRjKB7Ok?= =?us-ascii?Q?XtWmnvU4jdsUsGkXM5L+Z9n1WU90hTJTb5k86uKyco8wLtzM2lLQA3WMLflS?= =?us-ascii?Q?jfMxl/uug5t3cCDr0jKWeJGPfxy1rMQIzgrMXGtRpyLKUxW6xadRakZXgLpz?= =?us-ascii?Q?0kM4kDwaRhTUr3jKwzsu8shUU6/06UXrcQrH9VVStNiBRRLD0DTKcwviMLAO?= =?us-ascii?Q?Kly4Ei7eG9gtLErpJYkF+disNYyr5pw0L+G7eWXtgf2PXno1fZziBWf8iaI6?= =?us-ascii?Q?NanRoFRUvVG29m4o2PtvnOCKk9S5lW6AR8tmmeUi/tYTIBjTO4RtTuJo7HNN?= =?us-ascii?Q?MKJ357bDRI0R9vKZUTzePK/kPKbelev3GK6zP22TqrAfpnzY+rrW/v4H4SpI?= =?us-ascii?Q?VZqEe6ToUwiJ8E3v6EAAycJFbLEEJGr51INEez5dxXyIJ0DNNn4BdbPFXTSt?= =?us-ascii?Q?8USye8E3sVQ5V8LNfq8B95fJcYva3jfQlp0bGVwEk5l/gYpF1AFy8zRUcqTN?= =?us-ascii?Q?BTrg5CCJV9mmT0WBlYUbk+WWfl4ccFo245Fvirn7zYZxhoPNUccca4MJV+Ve?= =?us-ascii?Q?ISW0rVukVyZMpZkN+0B1a6G+?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 15159c70-1470-4a5c-4e24-08d926860e2e X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB5506.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Jun 2021 11:52:25.6597 (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: LNQ0cdhvW9NK3CeF/1pA+vxue41gOzI2Rq8C6unKJNQ8KChvd7LjaunneL9j466z X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5363 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 03, 2021 at 03:13:44PM +1000, David Gibson wrote: > > We can still consider it a single "address space" from the IOMMU > > perspective. What has happened is that the address table is not just a > > 64 bit IOVA, but an extended ~80 bit IOVA formed by "PASID, IOVA". > > True. This does complexify how we represent what IOVA ranges are > valid, though. I'll bet you most implementations don't actually > implement a full 64-bit IOVA, which means we effectively have a large > number of windows from (0..max IOVA) for each valid pasid. This adds > another reason I don't think my concept of IOVA windows is just a > power specific thing. Yes Things rapidly get into weird hardware specific stuff though, the request will be for things like: "ARM PASID&IO page table format from SMMU IP block vXX" Which may have a bunch of (possibly very weird!) format specific data to describe and/or configure it. The uAPI needs to be suitably general here. :( > > If we are already going in the direction of having the IOASID specify > > the page table format and other details, specifying that the page > > tabnle format is the 80 bit "PASID, IOVA" format is a fairly small > > step. > > Well, rather I think userspace needs to request what page table format > it wants and the kernel tells it whether it can oblige or not. Yes, this is what I ment. 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charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, Jun 03, 2021 at 03:13:44PM +1000, David Gibson wrote: > > We can still consider it a single "address space" from the IOMMU > > perspective. What has happened is that the address table is not just a > > 64 bit IOVA, but an extended ~80 bit IOVA formed by "PASID, IOVA". > > True. This does complexify how we represent what IOVA ranges are > valid, though. I'll bet you most implementations don't actually > implement a full 64-bit IOVA, which means we effectively have a large > number of windows from (0..max IOVA) for each valid pasid. This adds > another reason I don't think my concept of IOVA windows is just a > power specific thing. Yes Things rapidly get into weird hardware specific stuff though, the request will be for things like: "ARM PASID&IO page table format from SMMU IP block vXX" Which may have a bunch of (possibly very weird!) format specific data to describe and/or configure it. The uAPI needs to be suitably general here. :( > > If we are already going in the direction of having the IOASID specify > > the page table format and other details, specifying that the page > > tabnle format is the 80 bit "PASID, IOVA" format is a fairly small > > step. > > Well, rather I think userspace needs to request what page table format > it wants and the kernel tells it whether it can oblige or not. Yes, this is what I ment. Jason _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu