iommu page table consolidation and iommufd
summary
Generic IO page table code lands in 6.19 with AMD and VTD formats working, Risk5 on the mailing list and about three quarters of ARM in-tree, replacing six near-identical driver implementations and fixing VTD races via a common algorithm. Integration uses a multi‑compiled format layer, consolidated page table system, format-specific PT info for hardware programming, contiguous PTE grouping, and KUnit format tests that reliably catch bugs. Next work targets batched map/unmap to avoid repeated rewalks for a ~10% benchmark gain, debug dumping via RCU, SMMUv3 integration and improved MMUFD teardown performance.
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chapters (9)
- 0:00Introduction to IOMMUFD
- 1:46IOMMUFD progress and features
- 3:10Generic page table consolidation
- 10:30Driver integration and AMD example
- 16:30Page table format compilation
- 20:00Feature flags and optimizations
- 22:47Testing with KUnit
- 23:49Future optimizations and plans
- 26:21Q&A on page table configuration
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