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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?mtjm435sHx8Zw7oJLc0CovVcZP4stk6QDQJEa5WMyKEXLFhxLLLbZvhuqsVF?= =?us-ascii?Q?jF0GDHecfZctrKWvDQrjoThdraTR76K9L9TjDD+bLrObqj8cZkvZcbT9AwIK?= =?us-ascii?Q?BtMjSzgQeX5JCn1aVcxKJhsQ/mzW4ZFBo9c4Bwx6L8F0ffVThQgRTJZ0UZbi?= =?us-ascii?Q?m2ngJHEt7lOqsHQ246HTfU1UifitSPwi+sUlIEyizut2N7OtesCavDCD52/o?= =?us-ascii?Q?Hsvs9CN02iVUlENrDSULCYI6ThpQGelQMY1X0zmUzxYSmSihN29iIp2Z8SSa?= =?us-ascii?Q?0yTWMBK4N4PKplJVdsOlZlK6Zn+2PqjaHHteo/GlSnd5PIVfyuhT3HPhXQbd?= =?us-ascii?Q?oQ0vstP4WqeNRITkifPBy3CA0uYxCas5IQmp9LGU/k5RgKsc+NugyZ98Z3Nl?= =?us-ascii?Q?YUhxxmt2rly1CWhK+FTKra9s+dE38FU8qEDrX3wVS/QpU1bGwU/5biNSGiJV?= =?us-ascii?Q?HmQaxEyCRHXplw/nG7jl5+o45C1Ha71IOMOmwyjUp6iRNVfPFKJksmNna9Hg?= =?us-ascii?Q?TpVDe95cWGlc8yTfAUmK9eVQJHZp256OEr611SC0NIpAvLyS4lmkOYreEaY6?= =?us-ascii?Q?KL3y07Ho1JV1jc3xcbnEeEmO6CMqyz1yrPGfh69Vt3M9p6NKLINYrOVwXd1N?= =?us-ascii?Q?XUGLoz0vsK05byC4pE6wiNjxrEBXag6iWBjeTSOEC067a4nV8omu+0YT6erd?= =?us-ascii?Q?MmpPO4TJtUeMBnhijTjCJepXm5talYhkwBPZUckoIScFGSDwAjpAmj56yNga?= =?us-ascii?Q?HcmzGUShKVVwy7uQblizjHWkf/wLabxExKS/LgVrn4Jr/UUiXO/4BRsnGxEr?= =?us-ascii?Q?n2KqvBhPOfs+13SqxnQ67qWrBx8T2MoRzgRYPGB+vUtYP0b+/YUQWOjy9BRW?= =?us-ascii?Q?Sjpp34nA50pZfK7SjBL1Hn89kWhLfSCqyFrSY5TRaHPiPubA1W6ZvInmAQFU?= =?us-ascii?Q?XLg8CWYfh2Y0C3x35+869NsRa2paHHp3mkcCsOQNhoKKk3nXFx/zaf1yV0O+?= =?us-ascii?Q?UVWDsDrc/ZfFXhHWn3ALS1w7GNn0CUCnAjp6j/GIbYTqMsfTg+SapU3x2B8J?= =?us-ascii?Q?RlxC18R4iRgdoNl3kALUVG7k5JiIG7mF5M5TjK0ouh6CwnIavGFbuBTkagwf?= =?us-ascii?Q?NgmHHot+rTYGYIemrAZTN/Ca6enLUvgvgzVm9JW4nlRKJvcxv8eHWOHIkYME?= =?us-ascii?Q?tx4rtzGTzidsXZ45COBi3aPDZfR2LBttKiHmZdZYgFCm1pepZGHu2jWk/rX6?= =?us-ascii?Q?cLvL4FERdM0Sn4tfpY8kBdmsipLvjGU8Asy9L4np22wmSy9XtOF/NANFAmHn?= =?us-ascii?Q?0D9iqJsYvKUnXJcQd8yr26jX+YikUVM/xlbefRJFAvl5PUAcR6USTZeCknHz?= =?us-ascii?Q?D38T2wACEj4rsEMAnE/2glfusyJIicr9aEazyNVpCbYLVUfyvZF3MK0jB3DK?= =?us-ascii?Q?yr+rUoEg6FaXEGwZstgI0W/VebiWgiCxuSuZ0nv9jYwcse35VcVoCWgj+Dgw?= =?us-ascii?Q?qpG6g0fzP/4ADB3yzkErYTSVh/v1SR39RsgJzPAOb0bBary5ns6ZGA/oE7GA?= =?us-ascii?Q?eQS4kHTaiBryVFSJaGY7X/GWPa9VuLAk5E1iuywE?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 94e8a737-876f-48a0-8728-08dd687d267e X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Mar 2025 13:34:48.7320 (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: 2IuKN+c69obwKlXgvMZcNaAn7QIs6xSQ3A/LOHPLvALE5hVpcbucYwMIZQZ7Ol0j X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN0PR12MB5761 On Wed, Mar 19, 2025 at 06:55:42PM -0700, Changyuan Lyu wrote: > From: Alexander Graf > > Add the core infrastructure to generate Kexec HandOver metadata. Kexec > HandOver is a mechanism that allows Linux to preserve state - arbitrary > properties as well as memory locations - across kexec. > > It does so using 2 concepts: > > 1) State Tree - Every KHO kexec carries a state tree that describes the > state of the system. The state tree is represented as hash-tables. > Device drivers can add/remove their data into/from the state tree at > system runtime. On kexec, the tree is converted to FDT (flattened > device tree). Why are we changing this? I much prefered the idea of having recursive FDTs than this notion copying eveything into tables then out into FDT? Now that we have the preserved pages mechanism there is a pretty direct path to doing recursive FDT. I feel like this patch is premature, it should come later in the project along with a stronger justification for this approach. IHMO keep things simple for this series, just the very basics. > +int register_kho_notifier(struct notifier_block *nb) > +{ > + return blocking_notifier_chain_register(&kho_out.chain_head, nb); > +} > +EXPORT_SYMBOL_GPL(register_kho_notifier); And another different set of notifiers? :( > +static int kho_finalize(void) > +{ > + int err = 0; > + void *fdt; > + > + fdt = kvmalloc(kho_out.fdt_max, GFP_KERNEL); > + if (!fdt) > + return -ENOMEM; We go to all the trouble of keeping track of stuff in dynamic hashes but still can't automatically size the fdt and keep the dumb uapi to have the user say? :( :( Jason