ENUM IOMMU_HW_QUEUE_TYPE(9)

✨ enum iommu_hw_queue_type — HW Queue Type ✨

okay so bestie, welcome to the Kernel API Manual 💖 this page is literally just a little enum that tells the kernel which flavor of hardware queue you're talking about. that's it. that's the whole vibe. two constants, zero drama, but she's important iykyk 🫶

🌸 SYNOPSIS 🌸

here's the whole thing, copy-paste energy, no cap:

enum iommu_hw_queue_type {
    IOMMU_HW_QUEUE_TYPE_DEFAULT ,
    IOMMU_HW_QUEUE_TYPE_TEGRA241_CMDQV

};

like… she's short. she's sweet. she's an enum. slay 💅

🎀 Constants 🎀

• IOMMU_HW_QUEUE_TYPE_DEFAULT — lowkey a placeholder bestie 😭 reserved for future use, so don't go assigning it any main character energy just yet.
• IOMMU_HW_QUEUE_TYPE_TEGRA241_CMDQV — okay THIS one ate 🔥 it's the NVIDIA Tegra241 CMDQV, which is the extension for ARM SMMUv3, and it gives you a Virtual Command Queue (VCMDQ). iconic.

🦋 SEE ALSO 🦋

bestie there are… a lot of friends here. like, the whole iommufd friend group showed up 🌈 grab a snack, this is the full guest list, and yes, every single one is invited:

• Kernel file ./include/uapi/linux/iommufd.h
• General ioctl format(9)
• struct iommu_destroy(9)
• struct iommu_ioas_alloc(9)
• struct iommu_iova_range(9)
• struct iommu_ioas_iova_ranges(9)
• struct iommu_ioas_allow_iovas(9)
• enum iommufd_ioas_map_flags(9)
• struct iommu_ioas_map(9)
• struct iommu_ioas_noiommu_get_pa(9)
• struct iommu_ioas_map_file(9)
• struct iommu_ioas_copy(9)
• struct iommu_ioas_unmap(9)
• enum iommufd_option(9)
• enum iommufd_option_ops(9)
• struct iommu_option(9)
• enum iommufd_vfio_ioas_op(9)
• struct iommu_vfio_ioas(9)
• enum iommufd_hwpt_alloc_flags(9)
• enum iommu_hwpt_vtd_s1_flags(9)
• struct iommu_hwpt_vtd_s1(9)
• struct iommu_hwpt_arm_smmuv3(9)
• struct iommu_hwpt_amd_guest(9)
• enum iommu_hwpt_data_type(9)
• struct iommu_hwpt_alloc(9)
• enum iommu_hw_info_vtd_flags(9)
• struct iommu_hw_info_vtd(9)
• enum iommu_hw_info_arm_smmuv3_flags(9)
• struct iommu_hw_info_arm_smmuv3(9)
• struct iommu_hw_info_tegra241_cmdqv(9)
• struct iommu_hw_info_amd(9)
• enum iommu_hw_info_type(9)
• enum iommufd_hw_capabilities(9)
• enum iommufd_hw_info_flags(9)
• struct iommu_hw_info(9)
• struct iommu_hwpt_set_dirty_tracking(9)
• enum iommufd_hwpt_get_dirty_bitmap_flags(9)
• struct iommu_hwpt_get_dirty_bitmap(9)
• enum iommu_hwpt_invalidate_data_type(9)
• enum iommu_hwpt_vtd_s1_invalidate_flags(9)
• struct iommu_hwpt_vtd_s1_invalidate(9)
• struct iommu_viommu_arm_smmuv3_invalidate(9)
• struct iommu_hwpt_invalidate(9)
• enum iommu_hwpt_pgfault_flags(9)
• enum iommu_hwpt_pgfault_perm(9)
• struct iommu_hwpt_pgfault(9)
• enum iommufd_page_response_code(9)
• struct iommu_hwpt_page_response(9)
• struct iommu_fault_alloc(9)
• enum iommu_viommu_type(9)
• struct iommu_viommu_tegra241_cmdqv(9)
• struct iommu_viommu_alloc(9)
• struct iommu_vdevice_alloc(9)
• struct iommu_ioas_change_process(9)
• enum iommu_veventq_flag(9)
• struct iommufd_vevent_header(9)
• enum iommu_veventq_type(9)
• struct iommu_vevent_arm_smmuv3(9)
• struct iommu_vevent_tegra241_cmdqv(9)
• struct iommu_veventq_alloc(9)
• struct iommu_hw_queue_alloc(9)

ngl bestie, if you're reading this at 3am debugging an IOMMU, drink some water and go to bed after. the queues will still be there tomorrow 💜

and that's the page! 🎀 brought to you from the kernel source over in ./include/uapi/linux, dated October 2026, filed under enum iommu_hw_queue_type(9) — mwah, go forth and virtual-command-queue responsibly bestie 💅✨