STRUCT IOMMU_IOAS_MAP_FILE(9)

✨ struct iommu_ioas_map_file(9) ✨

okay so bestie, welcome to the Kernel API Manual 💖 this one's all about struct iommu_ioas_map_file — yes that's the ioctl(IOMMU_IOAS_MAP_FILE), we love a struct that moonlights as an ioctl 🎀

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🌸 NAME 🌸

struct iommu_ioas_map_file — literally just ioctl(IOMMU_IOAS_MAP_FILE), that's the whole vibe 💅

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🦋 SYNOPSIS 🦋

struct iommu_ioas_map_file {
    __u32 size;
    __u32 flags;
    __u32 ioas_id;
    __s32 fd;
    __aligned_u64 start;
    __aligned_u64 length;
    __aligned_u64 iova;
 };

look at her. iconic. seven fields, zero notes 💜

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🎀 Members 🎀

• size — it's sizeof(struct iommu_ioas_map_file), the classic "how big am I" flex ✨
• flags — same deal as for iommu_ioas_map, no cap 🫶
• ioas_id — also same as for iommu_ioas_map, matching energy 💫
• fd — the memfd (or a supported dma-buf file, ooh 👀) that you're mapping
• start — byte offset from the start of the file, like where in the file we're starting from bestie 📍
• length — same as for iommu_ioas_map, keeping the consistency streak alive 🌈
• iova — same as for iommu_ioas_map too, she said "match my sister's outfit" 💅

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🌟 Description 🌟

So what she actually does: she sets an IOVA mapping from a memfd file 🧚

On kernels with dma-buf support, supported dma-buf files may also be accepted — cute, we love options 😌

⚠️ but real talk: this is not a generic dma-buf import path. Do not come in here expecting that, bestie, it's giving "read the fine print" 💀

Currently supported dma-bufs include single-range VFIO PCI dma-bufs exported through VFIO_DEVICE_FEATURE_DMA_BUF — those are the ones getting the VIP treatment 👑 and other dma-bufs may be rejected 🙈 (sorry babes)

All other arguments and semantics match those of IOMMU_IOAS_MAP — like, exactly. Every one. Match made in heaven fr fr 🫶

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💫 SEE ALSO 💫

grab a snack, this list is long and she ATE 🍓

• 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_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)
• enum iommu_hw_queue_type(9)
• struct iommu_hw_queue_alloc(9)

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and that's the whole page, bestie, you're so welcome 💖✨🎀🦋🌸💅🫶

okay final sign-off cuteness: this little gem lives at ./include/uapi/linux, dated October 2026 🌈 she's from the future, main character energy fr, and the page is literally titled struct iommu_ioas_map_file(9) — go map something, iykyk 💜