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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?6+GvoW2Gy4+xr5HRNHFTdO+JHL6kSYKN7scCRIq/+GfnhH5yL+mFcwgCaba1?= =?us-ascii?Q?jtDyl5C2h5KsahOxMAmiRAe7WZstNGkbJRjGBVBKYeYZHv/CWxR1r8HgXOxK?= =?us-ascii?Q?rm9DrWxUIDWD2P4Hv83rimjAzQAjr6uouuxlzN9kXOjwoGOx5IiEPGesLZ6v?= =?us-ascii?Q?8fLQlBiyEgPEUNUWryw/kQpe6liH/E21OFYOMYZIZHup9h5Rhn+s+Jn0i0j1?= =?us-ascii?Q?IF2Hfp4yaVwBv1jG23kcgoAjGcuyD5ymuPRYt4jUSn74xhfG4+ZUUD8vXkw6?= =?us-ascii?Q?6ndLxsGnivFBCmnj2Fr/REp6mJLFqrhnFz/ao6c8L5Q3QvP9fQvVKbkws4Z2?= =?us-ascii?Q?wgOGDMA6uqSWaWzS2C3Zt+l/d3WwzNM5BURkv2AaznrY90NKEFimqnqP5e+y?= =?us-ascii?Q?iWABYnjFG0JxpNvao2arPzBEcGR1hJnwFxBH0E1TgOlhFdlaCQ48mOyKQD5i?= =?us-ascii?Q?GatkQacuwqnoltyIIBODrU/P2Q/iANvzDD7/f/lb7w4h6omnIUdLexHyAoDs?= =?us-ascii?Q?JfhBlGGdysNKfqfR7G30ZZ1FmfDhEDV0ogpgslYCWjhHwU1ee3chxD7+YZlI?= =?us-ascii?Q?v42OwKRRJEQAuEVuu7ZkMdTDQkkepJ41+sLGhYyM3fdydirqu9xwZrAhyqp5?= =?us-ascii?Q?EH3krMdqZ4T32fvB+nqVWg5HMtbmBeU6Cc+XwfYJQmXRC+4GtcuAnfMg+PTD?= =?us-ascii?Q?RFLlnNvKy5zdsNG4MYGGu6K8wNrbbuk+4KcJXg8dDVqadULhtoN3oCaZlhLB?= =?us-ascii?Q?dk5xHC3LfNmuml+xBM5AEbzR1EzXeaUxam7BvjluBTwS0l3s22ztKqbOdLsK?= =?us-ascii?Q?+uJL4UJv+4H37UFBWFuCYOMQg0XuWeyB5erLJhbgO2Wc126PkPOavSOxZX0b?= =?us-ascii?Q?TruoBXGc9+vBzqB6s4NpohFH71xPe9s7ZCy3hTQkBM+GNNkCFEKhWmx4PX1p?= =?us-ascii?Q?YhkU3avswLPWAMPZC01ujLwowsVxeus6xI0hJ9ReRAMrYGrEyTKBx3+CV1rU?= =?us-ascii?Q?ovoyG3GCvBsBe6LsyhE9zGJ+jr9mzw45YYFjRlCVqq+SWvUjl18OIcjC+bhV?= =?us-ascii?Q?dorH3fBw9sowlrEotnNXItuSa7j1SFlw5Ss4eTmKBDVzicbreQHFelkRcDZJ?= =?us-ascii?Q?wc62+v4wQXJJk8DDl9oECF1KxHNIw/U1Y9SGW1b7CCYK4XEoon96hyxN452B?= =?us-ascii?Q?gBzKkT//t2ZVYQ2D08L39OVZCMm2xdLDnNc4IRCg0KISGTD+UCEXjGKhA+rX?= =?us-ascii?Q?dXngHW5afQpn+95WMGgGoRUhiiZLZytlVhs9UCOX8flVqgej30Jer4SfICgS?= =?us-ascii?Q?zVxrdu6MFL9N1d6Uo2OOM1tx?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9f356322-5653-4d21-0c94-08d95803fa06 X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB5506.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Aug 2021 11:27:15.5180 (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: 5qOLVmToY+/se2ulBewv84zqtYYPzvdX0zsoeGivaVv0du+vmLuQFzkb7MNUpkvx X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5222 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 04, 2021 at 10:59:21PM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe > > Sent: Wednesday, August 4, 2021 10:05 PM > > > > On Mon, Aug 02, 2021 at 02:49:44AM +0000, Tian, Kevin wrote: > > > > > Can you elaborate? IMO the user only cares about the label (device cookie > > > plus optional vPASID) which is generated by itself when doing the attaching > > > call, and expects this virtual label being used in various spots (invalidation, > > > page fault, etc.). How the system labels the traffic (the physical RID or RID+ > > > PASID) should be completely invisible to userspace. > > > > I don't think that is true if the vIOMMU driver is also emulating > > PASID. Presumably the same is true for other PASID-like schemes. > > > > I'm getting even more confused with this comment. Isn't it the > consensus from day one that physical PASID should not be exposed > to userspace as doing so breaks live migration? Uh, no? > with PASID emulation vIOMMU only cares about vPASID instead of > pPASID, and the uAPI only requires user to register vPASID instead > of reporting pPASID back to userspace... vPASID is only a feature of one device in existance, so we can't make vPASID mandatory. Jason