[PATCH v13 0/4] vfio: selftest: Add NVIDIA GPU Falcon DMA test driver

Alex Williamson
2026-04-08T22:55:40Z

Patch 1:

Add a chunking loop to vfio_pci_driver_memcpy() so that it handles
arbitrarily sized memcpy requests by breaking them into
max_memcpy_size-sized chunks. This allows tests to request any memcpy
size. Update the test to use a size of 4x max_memcpy_size to exercise
the chunking logic.

Patch 2:

Add vfio_pci_cmd_set()/vfio_pci_cmd_clear() macros for PCI_COMMAND
operations.

Patch 3:

Allow drivers that cannot trigger MSI interrupts to leave the
send_msi callback NULL. Tests check ops->send_msi directly and
gracefully skip MSI-related operations when it is absent.

Patch 4:

Introduce the nv_falcon plugin driver, which extracts and adapts
relevant functionality from NVIDIA's gpu-admin-tools project [1] and
integrates it into the VFIO selftest framework. As a result, any
system equipped with a PCIe slot and a supported NVIDIA GPU can now
run VFIO DMA selftests using commonly available hardware.

Falcons are general-purpose microcontrollers present on NVIDIA GPUs
that can perform DMA operations between system memory and device
memory.

[1] https://github.com/NVIDIA/gpu-admin-tools

Note on version numbering: v1 through v9 were internal review
iterations that were mistakenly carried over to the upstream
submission. Apologies for the confusion, the internal changelog
has been dropped.

Changes for lucky v13:
- Respin from Alex. No fundamental changes here, so keeping
Rubin's authorships, sign-offs, and cover letter.
- Throughout: updated subject for consistency (David)
- Patch 1 & 3: No change, R-b collected
- Patch 2: Macros converted to static inlines (David)
- Patch 4:
- Formats %ll -> %l (David)
- Converted size_to_dma_encoding() size testing/manipulation
to asserts (David)
- Re-introduced iterative transfer for non-power-of-2 memcpy (David)
Testing this revealed we need some gymnastics to also avoid
transfers crossing block boundaries, so we use the largest power-
of-2 taking into account the transfer size as well as source and
destination IOVA addresses.
- Function renaming for consistency (David).

Rubin Du (4):
vfio: selftests: Add memcpy chunking to vfio_pci_driver_memcpy()
vfio: selftests: Add generic PCI command register helpers
vfio: selftests: Allow drivers without send_msi() support
vfio: selftests: Add NVIDIA Falcon driver for DMA testing

.../selftests/vfio/lib/drivers/nv_falcon/hw.h | 350 ++++++++
.../vfio/lib/drivers/nv_falcon/nv_falcon.c | 789 ++++++++++++++++++
.../lib/include/libvfio/vfio_pci_device.h | 14 +
tools/testing/selftests/vfio/lib/libvfio.mk | 2 +
.../selftests/vfio/lib/vfio_pci_driver.c | 21 +-
.../selftests/vfio/vfio_pci_driver_test.c | 57 +-
6 files changed, 1210 insertions(+), 23 deletions(-)
create mode 100644 tools/testing/selftests/vfio/lib/drivers/nv_falcon/hw.h
create mode 100644 tools/testing/selftests/vfio/lib/drivers/nv_falcon/nv_falcon.c

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