iommufd_viom..._hwpt_nested(9)

💅 iommufd_viom..._hwpt_nested(9) — the kernel API manual, but make it make sense

okay so bestie, welcome to the iommufd_viom..._hwpt_nested(9) page ✨ (yes the title got truncated, the kernel is dramatic like that 😭). This is the Kernel API Manual era of your life now, and honestly? You're gonna slay it.

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✨ NAME ✨

iommufd_viommu_alloc_hwpt_nested — get a hwpt_nested for a vIOMMU 🎀

Like, that's the whole vibe. You got a virtual IOMMU, you want a nested hardware pagetable for it, this is the function. Periodt.

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🌸 SYNOPSIS 🌸

struct iommufd_hwpt_nested * iommufd_viommu_alloc_hwpt_nested (struct
iommufd_viommu *viommu , u32 flags , const struct iommu_user_data
*user_data );

Copy it exactly, don't retype it from memory, I'm begging you 🙈 — return type is struct iommufd_hwpt_nested *, and it takes three args, in that order: a struct iommufd_viommu *viommu, a u32 flags, and a const struct iommu_user_data *user_data. No cap.

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🦋 ARGUMENTS 🦋

• viommu — the vIOMMU ojbect to associate the hwpt_nested/domain with 🫶 (the original page really does spell it "ojbect" and honestly? iconic. we keep it. it's part of the lore.)
• flags — flags, straight from userspace 💫
• user_data — the user_data pointer. Must be valid. 🚨 Not "probably valid", not "valid-ish", valid. Do not come in here with a garbage pointer, that's not the main character energy we're going for 💀

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🔥 DESCRIPTION 🔥

So what does it actually do? It allocates a brand new IOMMU_DOMAIN_NESTED for a vIOMMU 🌈 and hands it back to you as a NESTED hw_pagetable. That's it, that's the function. Allocate, nest, return, slay. 👑

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🎀 SEE ALSO 🎀

• Kernel file ./drivers/iommu/iommufd/hw_pagetable.c — go read it, that's where the actual sauce lives 💖
• iommufd_hwpt_paging_alloc(9) — the paging sibling 🧚
• iommufd_hwpt_nested_alloc(9) — the nested sibling ⭐

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Lowkey a flex: this page lives at ./drivers/iommu/iommufd, dated October 2026, in the Kernel API Manual. Bestie, in the Linux kernel, in the future. Obsessed. 🦋💜

okay bye, go allocate your nested hwpt responsibly, mwah 💋