STRUCT PT_IOMMU(9)

✨ struct pt_iommu(9) ✨

okay so bestie, welcome to the kernel API manual — this one's struct pt_iommu(9) and it's literally the blueprint, the main character struct, the whole vibe 💅

🌸 NAME 🌸

struct pt_iommu — the base structure for IOMMU page tables 🎀

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🦋 SYNOPSIS 🦋

struct pt_iommu {
    struct iommu_domain domain;
    const struct pt_iommu_ops *ops;
    const struct pt_iommu_driver_ops *driver_ops;
    int nid;
    struct device *iommu_device;
 };

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💖 Members 💖

• domain — the core IOMMU domain, the moment, the whole point 🫶 the driver should use a union to overlay this memory with its previously existing domain struct so it creates an alias. iykyk.
• ops — function pointers to access the API. that's it, that's the vibe ✨
• driver_ops — function pointers that the HW driver provides to help manage HW details like caches 💀 lowkey the hardware-handling squad.
• nid — the Node ID to use for table memory allocations. the IOMMU driver may want to set the NID to the device's NID if there are multiple table walkers 👀 (multiple walkers = much chaos, plan accordingly).
• iommu_device — device pointer used for any DMA cache flushing when PT_FEAT_DMA_INCOHERENT 🔥 this is the iommu device that created the page table, which must have dma ops that perform cache flushing. no cap, that part is non-negotiable.

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👑 Description 👑

so here's the tea: the format-specific struct will include this as the first member 🌈. that's the whole description, bestie — it's short but it ate.

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🔍 SEE ALSO 🔍

• Kernel file ./include/linux/generic_pt/iommu.h
• IOMMU Radix Page Table(9)
• struct pt_iommu_info(9)
• struct pt_iommu_driver_ops(9)
• struct pt_iommu_cfg(9)

go read the rest of the family, they're all iconic ⭐

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💜 fr fr take the iommu_device DMA-ops cache-flushing requirement seriously — that's a real correctness thing, not just a vibe check.

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later bestie!! this page lives in ./include/linux/generic_pt, stamped October 2026 — go touch some page tables 💅🎀🦋