On 12/1/2023 1:36 AM, Maxim Levitsky wrote: [...]
+ fpstate->user_size = fpu_user_cfg.default_size; + fpstate->user_xfeatures = fpu_user_cfg.default_features;The whole thing makes my head spin like the good old CD/DVD writers used to .... So just to summarize this is what we have: KERNEL FPU CONFIG /* all known and CPU supported user and supervisor features except - "dynamic" kernel features" (CET_S) - "independent" kernel features (XFEATURE_LBR) */ fpu_kernel_cfg.max_features; /* all known and CPU supported user and supervisor features except - "dynamic" kernel features" (CET_S) - "independent" kernel features (arch LBRs) - "dynamic" userspace features (AMX state) */ fpu_kernel_cfg.default_features; // size of compacted buffer with 'fpu_kernel_cfg.max_features' fpu_kernel_cfg.max_size; // size of compacted buffer with 'fpu_kernel_cfg.default_features' fpu_kernel_cfg.default_size; USER FPU CONFIG /* all known and CPU supported user features */ fpu_user_cfg.max_features; /* all known and CPU supported user features except - "dynamic" userspace features (AMX state) */ fpu_user_cfg.default_features; // size of non compacted buffer with 'fpu_user_cfg.max_features' fpu_user_cfg.max_size; // size of non compacted buffer with 'fpu_user_cfg.default_features' fpu_user_cfg.default_size; GUEST FPU CONFIG /* all known and CPU supported user and supervisor features except - "independent" kernel features (XFEATURE_LBR) */ fpu_guest_cfg.max_features; /* all known and CPU supported user and supervisor features except - "independent" kernel features (arch LBRs) - "dynamic" userspace features (AMX state) */ fpu_guest_cfg.default_features; // size of compacted buffer with 'fpu_guest_cfg.max_features' fpu_guest_cfg.max_size; // size of compacted buffer with 'fpu_guest_cfg.default_features' fpu_guest_cfg.default_size;
Good suggestion! Thanks! how about adding them in patch 5 to make the summaries manifested?
--- So in essence, guest FPU config is guest kernel fpu config and that is why 'fpu_user_cfg.default_size' had to be used above. How about that we have fpu_guest_kernel_config and fpu_guest_user_config instead to make the whole horrible thing maybe even more complicated but at least a bit more orthogonal?
I think it becomes necessary when there were more guest user/kernel xfeaures requiring special handling like CET-S MSRs, then it looks much reasonable to split guest config into two, but now we only have one single outstanding xfeature for guest. IMHO, existing definitions still work with a few comments. But I really like your ideas of making things clean and tidy :-)
