STRUCT IOMMU_VIOMMU_SELFTEST(9)

✨ struct iommu_viommu_selftest ✨

okay bestie, buckle up 💖 this is a page straight out of the Kernel API Manual, and it's about struct iommu_viommu_selftest — literally the vIOMMU data for the Mock driver, and the type tag for it is IOMMU_VIOMMU_TYPE_SELFTEST 🎀

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🌸 NAME 🌸

struct iommu_viommu_selftest — the vIOMMU data for the Mock driver, specifically for IOMMU_VIOMMU_TYPE_SELFTEST 🦋 (yes that's the whole vibe, she's a test struct and she knows it)

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⭐ SYNOPSIS ⭐

here's the shape of her, no cap, exactly like this:

struct iommu_viommu_selftest {
    __u32 in_data;
    __u32 out_data;
    __aligned_u64 out_mmap_offset;
    __aligned_u64 out_mmap_length;
 };

(that little stray space before the closing brace? iconic. we keep it. 💅)

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👑 Members 👑

okay so the glow-up tour of every single field, one by one, because we do NOT skip members in this house:

• in_data — the input random data, coming at us from user space 🫶 it's giving "surprise me" energy
• out_data — the output data heading back out to user space, and plot twist: it matches in_data 💖
• out_mmap_offset — this one is literally the offset argument for the mmap syscall 🌈 no extra lore, that's the whole job
• out_mmap_length — and this is the length argument for the mmap syscall ⭐ same deal, she's just the argument

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🦋 Description 🦋

okay so the actual behaviour is so simple it's almost funny: it just sets out_data=in_data and calls it a loopback test 😭🔥 what you put in is what you get out. that's it. that's the whole test. she ate and left zero crumbs 👑

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💜 SEE ALSO 💜

go read the source, bestie, it's right here — kernel file ./drivers/iommu/iommufd/iommufd_test.h 🌸 and while you're at it, these three are her besties:

• struct iommu_hwpt_selftest(9)
• struct iommu_hwpt_invalidate_selftest(9)
• struct iommu_viommu_invalidate_selftest(9)

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lowkey a reminder: this lives under ./drivers/iommu/iommufd and she's stamped October 2026 ⭐

and that's the page, bestie 🎀 mwah 💋 — this has been struct iommu...mmu_selftest(9) from the Kernel API Manual, source ./drivers/iommu/iommufd, dated October 2026. go forth and loopback test responsibly 🧚💜