Re: [PATCH v3 0/3] vfio: selftests: Add MMIO DMA mapping test

Alex Williamson
2026-01-19T20:39:45Z

On Wed, 14 Jan 2026 10:57:15 -0800
Alex Mastro <amastro@fb.com> wrote:

> Test IOMMU mapping the BAR mmaps created during vfio_pci_device_setup().
>
> All IOMMU modes are tested: vfio_type1 variants are expected to succeed,
> while non-type1 modes are expected to fail. iommufd compat mode can be
> updated to expect success once kernel support lands. Native iommufd will
> not support mapping vaddrs backed by MMIO (it will support dma-buf based
> MMIO mapping instead).
>
> Changes in v3:
> - Rename mmap_aligned() to mmap_reserve()
> - Reorder variable declarations for reverse-fir-tree style
> - Update patch 2 commit message to mention MADV_HUGEPAGE and MAP_FILE
> - Move BAR size check into map_partial_bar test only
> - Link to v2: https://lore.kernel.org/r/20260113-map-mmio-test-v2-0-e6d34f09c0bb@fb.com
>
> Changes in v2:
> - Split into patch series
> - Factor out mmap_reserve() for vaddr alignment
> - Align BAR mmaps to improve hugepage IOMMU mapping efficiency
> - Centralize MODE_* string definitions
> - Add is_power_of_2() assertion for BAR size
> - Simplify align calculation to min(size, 1G)
> - Add map_bar_misaligned test case
> - Link to v1: https://lore.kernel.org/all/20260107-scratch-amastro-vfio-dma-mapping-mmio-test-v1-1-0cec5e9ec89b@fb.com
>
> Signed-off-by: Alex Mastro <amastro@fb.com>
>
> ---
> Alex Mastro (3):
> vfio: selftests: Centralize IOMMU mode name definitions
> vfio: selftests: Align BAR mmaps for efficient IOMMU mapping
> vfio: selftests: Add vfio_dma_mapping_mmio_test
>
> tools/testing/selftests/vfio/Makefile | 1 +
> tools/testing/selftests/vfio/lib/include/libvfio.h | 9 ++
> .../selftests/vfio/lib/include/libvfio/iommu.h | 6 +
> tools/testing/selftests/vfio/lib/iommu.c | 12 +-
> tools/testing/selftests/vfio/lib/libvfio.c | 25 ++++
> tools/testing/selftests/vfio/lib/vfio_pci_device.c | 24 +++-
> .../selftests/vfio/vfio_dma_mapping_mmio_test.c | 143 +++++++++++++++++++++
> .../testing/selftests/vfio/vfio_dma_mapping_test.c | 2 +-
> 8 files changed, 214 insertions(+), 8 deletions(-)
> ---
> base-commit: d721f52e31553a848e0e9947ca15a49c5674aef3
> change-id: 20260112-map-mmio-test-b4e4c2d917a9
>
> Best regards,

Applied to vfio next branch for v6.20/7.0. Thanks,

Alex