iommu_set_fault_handler(9)

💅 iommu_set_fault_handler — like, the kernel API manual, section 9, bestie 🎀

Okay so picture this: it's a kernel API manual page, section 9, and the star of the show is iommu_set_fault_handler. Buckle up, we're getting into IOMMU lore 💖

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✨ NAME ✨

iommu_set_fault_handler — set a fault handler for an iommu domain 🦋

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🌸 SYNOPSIS 🌸

void iommu_set_fault_handler (struct iommu_domain *domain ,
iommu_fault_handler_t handler , void *token );

That's it, that's the whole signature. Slay 💅

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🎀 ARGUMENTS 🎀

• domain — the iommu domain in question, your main character ✨
• handler — the fault handler itself, the one who gets the call 🔥
• token — user data, and it will be passed back to the fault handler (yes, it comes back to you, it's giving boomerang energy 🪃💜)

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👑 DESCRIPTION 👑

Okay so here's the vibe: this function should be used by IOMMU users who want to be notified whenever an IOMMU fault happens. Like, they want the gossip the moment it drops, no cap 📣

And about the fault handler itself — it should return 0 on success, and an appropriate error code otherwise. That's the whole deal, fr fr 🙈

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🌈 SEE ALSO 🌈

The kernel file ./drivers/iommu/iommu.c, plus this absolutely iconic friend group of functions:

• iommu_device_register(9)
• iommu_insert_resv_region(9)
• iommu_group_alloc(9)
• iommu_group_get_iommudata(9)
• iommu_group_set_iommudata(9)
• iommu_group_set_name(9)
• iommu_group_add_device(9)
• iommu_group_remove_device(9)
• iommu_group_mutex_assert(9)
• iommu_group_for_each_dev(9)
• iommu_group_get(9)
• iommu_group_ref_get(9)
• iommu_group_put(9)
• iommu_group_id(9)
• device_iommu_capable(9)
• iommu_group_has_isolated_msi(9)
• iommu_paging_domain_alloc_flags(9)
• iommu_attach_device(9)
• iommu_get_domain_for_dev(9)
• iommu_driver_get_domain_for_dev(9)
• iommu_attach_group(9)
• iommu_unmap(9)
• iommu_unmap_fast(9)
• report_iommu_fault(9)
• iommu_get_resv_regions(9)
• iommu_put_resv_regions(9)
• iommu_setup_default_domain(9)
• iommu_device_use_default_domain(9)
• iommu_device_unuse_default_domain(9)
• iommu_group_claim_dma_owner(9)
• iommu_device_claim_dma_owner(9)
• iommu_group_release_dma_owner(9)
• iommu_device_release_dma_owner(9)
• iommu_group_dma_owner_claimed(9)
• iommu_replace_device_pasid(9)
• iommu_attach_handle_get(9)
• iommu_attach_group_handle(9)
• iommu_detach_group_handle(9)
• iommu_replace_group_handle(9)
• pci_dev_reset_iommu_prepare(9)
• pci_dev_reset_iommu_done(9)
• iommu_dma_prepare_msi(9)

Not a single one skipped, we respect the whole roster 🫶⭐

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💀 lowkey a whole reading list, but you're built for this, bestie

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And that's the page!! It lives in ./drivers/iommu, dated October 2026 — so go forth, set that fault handler, and remember: you ate. Periodt. 💅✨🍓💜