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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ZVykLWdKOqYZ/bGPDDPPYPX0aAsluAugPNW07jux/hTodmXsI3S9GveJkBNm?= =?us-ascii?Q?DyiQpmbJJQ9uUYPU0W0yIeRqmb7RN+WhLHU/chcLF2JVWMlbNtS+tN4nKDRb?= =?us-ascii?Q?9M/FLrbGImxvHmfYOOR1BKT1Mev3Eq8TQuZ/Lc0Hh26vqIVTaiNZZfdhQyJL?= =?us-ascii?Q?5reBwERYcPSKaAIJPcnmmNilgTef8mOFm3f9rbVcxK3DN+ch2EE5VDwFpw9A?= =?us-ascii?Q?y03XrixMBdWfk+uXkwL5mz9Xlvq17k3cuWdv4bKACpC1C8Qgpa3s8W90tEXc?= =?us-ascii?Q?zm1wOXVnWulWS/gKRtMAl1cO9v8K+vkeLdELWQY0JHUXKhC/ydbYO/YO3Lhg?= =?us-ascii?Q?eOl86V/8lOcS5yKfiS8Vu3OSSafejpGeFPCFJxof/7rfqzmaQ6VuURfLAyIr?= =?us-ascii?Q?lFJS40EatmxQ+sDyWFyI8GDMC3aKGP63uGPvu1FdIq5tCy8P3j+z1zHOXj5g?= =?us-ascii?Q?r+p2YFHQbjNAn/7EQjJVp7IvPKjrv5WQ4bkW+zwOaWNMD+VKW8xcqb3Y1eaz?= =?us-ascii?Q?yvjvUt5li9l8w5MSx6auMtqe4eVAeqQmpRTkQ7KgqRuKzHvv9Gas3IaN3yMn?= =?us-ascii?Q?3f6AITVBCyR7b9gXN0OIhViaaZoWjMtXryQIgVVvKpL3Y95VDnTg7OeUg15h?= =?us-ascii?Q?EwHQyemnFl1s2TJK1x/74XLcysq+zhr8xhksq+rrErlr8HkicguYHfiKTgim?= =?us-ascii?Q?uoBH6OdecgWdiOmjB2Z2dQtJuZl0abd6L23KH+uzVHu5BzGyJw7xoHqfibw7?= =?us-ascii?Q?V8wIlO+PjCxkknnQx+ExTaKeMT/umVbaRHweXIgHQPgaiJSDackNdUKvIKCO?= =?us-ascii?Q?DmhmfQCfQG7EbcArlxLKY46ZqAeQHTMagOsVhCVwKmKpt4ah3OL5VOtXMOKw?= =?us-ascii?Q?nnW9vlxVWO8gMSPrMgcdDN0YgHkr8ku6+CfZA0vMP4/DpzO4Qye1N5eDVf1L?= =?us-ascii?Q?xYjlFHvZoEx+HzDz0pA8AnZ+NKmIOx/YnOnMd0b5SqwQalrMVwGjwbcUJGTK?= =?us-ascii?Q?kdPcqzV2nMIoi2UgSMnRhgfWrAyeEkMUIRBLbDkQdvbsRQlI++rpfi0QtneU?= =?us-ascii?Q?Hkop37jThmUY8ZQryJPvSuSJG5EHP2EbR8xg91v9uGIX5fH7ZEwd+so3P7cU?= =?us-ascii?Q?EkOFgz2UU0bF+iKSyClLi/RMWPAnDJESwlS0mKwrXqJSUoGwGkGTpJIOsWqg?= =?us-ascii?Q?Z9UVQoBbpfVnrsrejOrGyPCRFdBZQQjO0C00xhVY3vJwhOuZ1XVaohWzZTKg?= =?us-ascii?Q?Sr/HxmudcVF/O0oIAakhPzldsQCwbxLPUoW/F7FnDG7v6PMB2M7717Xm781A?= =?us-ascii?Q?HlDAIj+ZuSuwA+gv/8gahw4qLO31teWlbKrCarfI3ERMlZAonkmejluRlWd3?= =?us-ascii?Q?gdhO0UcROFiOt2/m8r4UBnLt1xcVzXl/YrGr774qsFNcxZrfsacH290+NwH3?= =?us-ascii?Q?uMcZzhOYsTp7t8Hq0HAc+Hq5xupggye3cgPGBN9aXWuCPbzeYrBvqW/4/Jw2?= =?us-ascii?Q?mUUB2ErXTz4yNAJ27HTnw7WVHIw1NuTJfKeohjJAgpdhO/5vfjPcV91+9Wan?= =?us-ascii?Q?xS+zp1QWywg6AUrObiHN2naccNdHL7yDJ8LZSREXyFjwQaw2mM73rhv2eAt2?= =?us-ascii?Q?CVbUZlwh9rVZnnR4N/+mwmn8zcdfqIeWNqmp1hhNTxokPnLsJrIE+18ZmrpW?= =?us-ascii?Q?Ied/tCzCNqa7Wri++doaCOQA3NFej8R/NXglz1cxGyspfis3?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: f460dc3d-6fed-4624-08b7-08dedc5bd4a6 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jul 2026 19:13:30.2635 (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: GF6DaNbutUrHetFBHT4QNiYl7tfKpi2lK+ONDNDMfjgh6I606BlZM/Ml/2Ebiga+ X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7306 On Tue, Jul 07, 2026 at 12:27:00AM -0700, Nicolin Chen wrote: > On Mon, Jul 06, 2026 at 01:26:40PM -0300, Jason Gunthorpe wrote: > > + /* > > + * There are at most 5 possible values for NUM based on SCALE. The > > Mind elaborating the "at most 5 possible values for NUM"? Oh, I guess it is at most 6 since it is +1 How about: /* * The spec defines the invalidated range as: * Range = ((NUM+1) * 2^SCALE) * Translation_Granule_Size * NUM is 5 bits, so (NUM+1) covers 1..32 granules and SCALE scales * that by a power of two. We must pick NUM and SCALE so the range * covers num_tg granules, i.e. (NUM+1) * 2^SCALE >= num_tg with * NUM+1 <= 32. That constrains SCALE to: * ceil(num_tg / 2^SCALE) <= 32 * SCALE >= ceil(log2(num_tg / 32)) * Choosing the smallest such SCALE gives the finest granularity and * thus the tightest (least over-covering) range, and equivalently the * largest NUM. * * Unlike other IOMMUs the spec has no alignment requirement on the * address beyond alignment to tg (so long as TTL=0). */ Jason