STRUCT HL_VM(9)

💖 struct hl_vm(9) — kernel API manual, but make it make sense 💖

okay so welcome to struct hl_vm, bestie — it's the virtual memory manager for MMU and it lives in the Kernel API Manual (section 9, kernel-space girlies only ✨). this is the group chat where DRAM pages, idr handles, and a refcount all figure out their whole situation. let's get into it 🫶

✨ SYNOPSIS ✨

like, here's the whole vibe. literally the entire struct, no edits, i promise:

struct hl_vm {
    struct gen_pool         *dram_pg_pool;
    struct kref             dram_pg_pool_refcount;
    spinlock_t idr_lock;
    struct idr              phys_pg_pack_handles;
    u8 init_done;
 };

🎀 MEMBERS 🎀

• dram_pg_pool — the pool for DRAM physical pages of 2MB. yes, 2MB, that's the whole unit. it's giving bulk-supply energy 💅
• dram_pg_pool_refcount — reference counter for the pool usage. bestie is keeping tabs on who's using the pool 👀
• idr_lock — protects the phys_pg_list_handles. it's the bouncer at the door, no cap 🚪
• phys_pg_pack_handles — an idr to hold all device allocation handles. all of them. every single one. the way it just holds them 😭
• init_done — whether initialization was done. and here's the why, straight from the source: we need this because VM initialization might be skipped during device initialization. so like... sometimes the VM doesn't get its moment at device-init o'clock and we still gotta know 🙈

🌈 SEE ALSO 🌈

the whole extended friend group, in order, every single one (iykyk) 👑

• the kernel file ./drivers/accel/habanalabs/common/habanalabs.h
• enum hl_mmu_page_table_location(9)
• struct iterate_module_ctx(9)
• struct hl_gen_wait_properties(9)
• struct pgt_info(9)
• enum hl_pci_match_mode(9)
• enum hl_fw_component(9)
• enum hl_fw_types(9)
• enum hl_queue_type(9)
• struct hw_queue_properties(9)
• enum vm_type(9)
• enum mmu_op_flags(9)
• enum hl_device_hw_state(9)
• struct hl_mmu_properties(9)
• struct hl_hints_range(9)
• struct asic_fixed_properties(9)
• struct hl_fence(9)
• struct hl_cs_compl(9)
• struct hl_ts_buff(9)
• struct hl_mem_mgr(9)
• struct hl_mem_mgr_fini_stats(9)
• struct hl_mmap_mem_buf_behavior(9)
• struct hl_mmap_mem_buf(9)
• struct hl_cb(9)
• struct hl_sync_stream_properties(9)
• struct hl_encaps_signals_mgr(9)
• struct hl_hw_queue(9)
• struct hl_cq(9)
• struct hl_ts_free_jobs(9)
• struct hl_user_interrupt(9)
• struct timestamp_reg_free_node(9)
• struct hl_user_pending_interrupt(9)
• struct hl_eq(9)
• struct hl_dec(9)
• enum hl_asic_type(9)
• enum hl_pm_mng_profile(9)
• enum hl_pll_frequency(9)
• struct pci_mem_region(9)
• struct static_fw_load_mgr(9)
• struct fw_response(9)
• struct dynamic_fw_load_mgr(9)
• struct pre_fw_load_props(9)
• struct fw_image_props(9)
• struct fw_load_mgr(9)
• struct engines_data(9)
• struct hl_asic_funcs(9)
• enum hl_va_range_type(9)
• struct hl_va_range(9)
• struct hl_cs_counters_atomic(9)
• struct hl_dmabuf_priv(9)
• struct hl_cs_outcome(9)
• struct hl_cs_outcome_store(9)
• struct hl_ctx(9)
• struct hl_ctx_mgr(9)
• struct hl_userptr(9)
• struct hl_cs(9)
• struct hl_cs_job(9)
• struct hl_cs_parser(9)
• struct hl_vm_hash_node(9)
• struct hl_vm_hw_block_list_node(9)
• struct hl_vm_phys_pg_pack(9)
• struct hl_vm_va_block(9)
• struct hl_debug_params(9)
• struct hl_notifier_event(9)
• struct hl_fpriv(9)
• struct hl_info_list(9)
• struct hl_debugfs_entry(9)
• struct hl_dbg_device_entry(9)
• struct hl_debugfs_cfg_access_entry(9)
• struct hl_debugfs_cfg_access(9)
• struct hl_hw_obj_name_entry(9)
• struct hl_mon_state_dump(9)
• struct hl_sync_to_engine_map_entry(9)
• struct hl_sync_to_engine_map(9)
• struct hl_state_dump_specs_funcs(9)
• struct hl_state_dump_specs(9)
• struct hl_device_reset_work(9)
• struct hl_mmu_priv(9)
• struct hl_mmu_per_hop_info(9)
• struct hl_mmu_hop_info(9)
• struct hl_hr_mmu_funcs(9)
• struct hl_mmu_funcs(9)
• struct hl_prefetch_work(9)
• struct multi_cs_completion(9)
• struct multi_cs_data(9)
• struct hl_clk_throttle_timestamp(9)
• struct hl_clk_throttle(9)
• struct user_mapped_block(9)
• struct cs_timeout_info(9)
• struct undefined_opcode_info(9)
• struct page_fault_info(9)
• struct razwi_info(9)
• struct hw_err_info(9)
• struct fw_err_info(9)
• struct engine_err_info(9)
• struct hl_error_info(9)
• struct hl_reset_info(9)
• struct eq_heartbeat_debug_info(9)
• struct hl_device(9)
• struct hl_cs_encaps_sig_handle(9)
• struct hl_info_fw_err_info(9)
• hl_ioctl_t(9)
• struct hl_ioctl_desc(9)
• hl_get_sg_info(9)
• hl_mem_area_inside_range(9)
• hl_mem_area_crosses_range(9)

okay that's the whole thing, you officially know struct hl_vm better than half the codebase 💜

ngl the only thing you gotta remember-remember is that init_done exists because VM init might get skipped during device initialization. that's the whole lore drop 🍓

and that's a wrap, bestie!! this page came to you from ./drivers/accel/habanalabs/common, dated October 2026 — struct hl_vm(9), main character energy, periodt 💅✨🦋