Commit Graph

24 Commits

Author SHA1 Message Date
David Matlack
03e073bc4d vfio: selftests: Fix .gitignore for already tracked files
Fix the rules in tools/testing/selftests/vfio/.gitignore to not ignore
some already tracked files (.gitignore, Makefile, lib/libvfio.mk).

This change should be a no-op, since these files are already tracked by git
and thus git will not ignore updates to them even though they match the
ignore rules in the VFIO selftests .gitignore file.

However, they do generate warnings with W=1, as reported by the kernel test
robot.

  $ KBUILD_EXTRA_WARN=1 scripts/misc-check
  tools/testing/selftests/vfio/.gitignore: warning: ignored by one of the .gitignore files
  tools/testing/selftests/vfio/Makefile: warning: ignored by one of the .gitignore files
  tools/testing/selftests/vfio/lib/libvfio.mk: warning: ignored by one of the .gitignore files

Fix this by explicitly un-ignoring the tracked files.

Fixes: 292e9ee22b ("selftests: Create tools/testing/selftests/vfio")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508280918.rFRyiLEU-lkp@intel.com/
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250828185815.382215-1-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-28 13:40:51 -06:00
David Matlack
fd134b0f2f vfio: selftests: Add a script to help with running VFIO selftests
Introduce run.sh, a script to help with running VFIO selftests. The
script is intended to be used for both humans manually running VFIO
selftests, and to incorporate into test automation where VFIO selftests
may run alongside other tests. As such the script aims to be hermetic,
returning the system to the state it was before the test started.

The script takes as input the BDF of a device to use and a command to
run (typically the command would be a VFIO selftest). e.g.

  $ ./run.sh -d 0000:6a:01.0 ./vfio_pci_device_test

 or

  $ ./run.sh -d 0000:6a:01.0 -- ./vfio_pci_device_test

The script then handles unbinding device 0000:6a:01.0 from its current
driver, binding it to vfio-pci, running the test, unbinding from
vfio-pci, and binding back to the original driver.

When run.sh runs the provided test, it does so by appending the BDF as
the last parameter. For example:

  $ ./run.sh -d 0000:6a:01.0 -- echo hello

Results in the following being printed to stdout:

  hello 0000:6a:01.0

The script also supports a mode where it can break out into a shell so
that multiple tests can be run manually.

  $ ./run.sh -d 0000:6a:01.0 -s
  $ echo $VFIO_SELFTESTS_BDF
  $ ./vfio_pci_device_test
  $ exit

Choosing which device to use is up to the user.

In the future this script should be extensible to tests that want to use
multiple devices. The script can support accepting -d BDF multiple times
and parse them into an array, setup all the devices, pass the list of
BDFs to the test, and then cleanup all the devices.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-31-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:11 -06:00
David Matlack
8afcbe2047 vfio: selftests: Make iommufd the default iommu_mode
Now that VFIO selftests support iommufd, make it the default mode.
IOMMUFD is the successor to VFIO_TYPE1{,v2}_IOMMU and all new features
are being added there, so it's a slightly better fit as the default
mode.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-30-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:11 -06:00
David Matlack
61cbfe5014 vfio: selftests: Add iommufd mode
Add a new IOMMU mode for using iommufd directly. In this mode userspace
opens /dev/iommu and binds it to a device FD acquired through
/dev/vfio/devices/vfioX.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-29-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:11 -06:00
David Matlack
d1a17495bb vfio: selftests: Add iommufd_compat_type1{,v2} modes
Add new IOMMU modes for using iommufd in compatibility mode with
VFIO_TYPE1_IOMMU and VFIO_TYPE1v2_IOMMU.

In these modes, VFIO selftests will open /dev/iommu and treats it as a
container FD (as if it had opened /dev/vfio/vfio) and the kernel
translates the container ioctls to iommufd calls transparently.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-28-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:10 -06:00
David Matlack
0969c685ba vfio: selftests: Add vfio_type1v2_mode
Add a new IOMMU mode for using VFIO_TYPE1v2_IOMMU.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-27-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:10 -06:00
David Matlack
892aff147a vfio: selftests: Replicate tests across all iommu_modes
Automatically replicate vfio_dma_mapping_test and vfio_pci_driver_test
across all supported IOMMU modes using fixture variants. Both of these
tests exercise DMA mapping to some degree so having automatic coverage
across all IOMMU modes will help catch bugs.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-26-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:10 -06:00
David Matlack
5df9bd6205 vfio: selftests: Encapsulate IOMMU mode
Encapsulate the "IOMMU mode" a test should use behind a new struct.
In the future this will be used to support other types of IOMMUs besides
VFIO_TYPE1_IOMMU, and allow users to select the mode on the command
line.

No functional change intended.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-25-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:09 -06:00
David Matlack
118e073ef6 vfio: selftests: Move helper to get cdev path to libvfio
Move the helper function to get the VFIO cdev path to libvfio so that it
can be used in libvfio in a subsequent commit.

No functional change intended.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-24-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:09 -06:00
David Matlack
35b05bd962 vfio: selftests: Add driver for Intel DSA
Add a driver to VFIO selftests for Intel DSA devices.

For now the driver only supports up to 32 batches and 1024 copies per
batch, which were the limits of the hardware this commit was tested
with. This is sufficient to generate 9+ minutes of DMA memcpys at a rate
of over 30 GB/s. This should be plenty to stress test VFIO and the IOMMU.

The driver does not yet support requesting interrupt handles, as this
commit was not tested against hardware that requires it.

Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-23-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:09 -06:00
David Matlack
2223587df5 vfio: selftests: Add driver for Intel CBDMA
Add a driver for the Intel CBDMA device. This driver is based on and
named after the Linux driver for this device (drivers/dma/ioat/) and
also based on previous work from Peter Shier <pshier@google.com>.

The driver aims to be as simple as possible. It uses a single descriptor
to issue DMA operations, and only supports the copy operation. For "DMA
storms", the driver kicks off the maximum number of maximum-sized DMA
operations. On Skylake server parts, this was 2^16-1 copies of size 2M
and lasts about 15 seconds.

Create symlinks to drivers/dma/ioat/{hw.h,registers.h} to get access to
various macros (e.g. IOAT_CHANCMD_RESET) and struct ioat_dma_descriptor.

Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-20-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:08 -06:00
David Matlack
fded8da4bc vfio: sefltests: Add vfio_pci_driver_test
Add a new selftest that tests all driver operations. This test serves
both as a demonstration of the driver framework, and also as a
correctness test for future drivers.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-14-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:05 -06:00
David Matlack
1b197032ac vfio: selftests: Add driver framework
Add a driver framework to VFIO selftests, so that devices can generate
DMA and interrupts in a common way that can be then utilized by tests.
This will enable VFIO selftests to exercise real hardware DMA and
interrupt paths, without needing any device-specific code in the test
itself.

Subsequent commits will introduce drivers for specific devices.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-13-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:05 -06:00
David Matlack
50d8fe805f vfio: selftests: Add a helper for matching vendor+device IDs
Add a helper function for matching a device against a given vendor and
device ID. This will be used in a subsequent commit to match devices
against drivers.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-12-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:05 -06:00
David Matlack
924947804f vfio: selftests: Enable asserting MSI eventfds not firing
Make it possible to assert that a given MSI eventfd did _not_ fire by
adding a helper to mark an eventfd non-blocking. Demonstrate this in
vfio_pci_device_test by asserting the MSI eventfd did not fire before
vfio_pci_irq_trigger().

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-11-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:04 -06:00
David Matlack
346cd58f1f vfio: selftests: Keep track of DMA regions mapped into the device
Keep track of the list of DMA regions that are mapped into the device
using a linked list and a new struct vfio_dma_region and use that to add
{__,}to_iova() for converting host virtual addresses into IOVAs.

This will be used in a subsequent commit to map multiple DMA regions
into a device that are then used by drivers.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-10-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:04 -06:00
Josh Hilke
47f861048e vfio: selftests: Validate 2M/1G HugeTLB are mapped as 2M/1G in IOMMU
Update vfio dma mapping test to verify that the IOMMU uses 2M and 1G
mappings when 2M and 1G HugeTLB pages are mapped into a device
respectively.

This validation is done by inspecting the contents of the I/O page
tables via /sys/kernel/debug/iommu/intel/. This validation is skipped if
that directory is not available (i.e. non-Intel IOMMUs).

Signed-off-by: Josh Hilke <jrhilke@google.com>
[reword commit message, refactor code]
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-9-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:04 -06:00
Josh Hilke
751f6b5d06 vfio: selftests: Add DMA mapping tests for 2M and 1G HugeTLB
Add test coverage of mapping 2M and 1G HugeTLB to vfio_dma_mapping_test
using a fixture variant. If there isn't enough HugeTLB memory available
for the test, just skip them.

Signed-off-by: Josh Hilke <jrhilke@google.com>
[switch from command line option to fixture variant]
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-8-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:03 -06:00
Josh Hilke
a0fd0af504 vfio: selftests: Add test to reset vfio device.
Add a test to vfio_pci_device_test which resets the device. If reset is
not supported by the device, the test is skipped.

Signed-off-by: Josh Hilke <jrhilke@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-7-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:03 -06:00
Josh Hilke
b477e7bcd2 vfio: selftests: Move vfio dma mapping test to their own file
Move the dma_map_unmap test from vfio_pci_device_test to a new test:
vfio_dma_mapping_test. We are going to add more complex dma mapping
tests, so it makes sense to separate this from the vfio pci device
test which is more of a sanity check for vfio pci functionality.

Signed-off-by: Josh Hilke <jrhilke@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-6-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:02 -06:00
Josh Hilke
790588f06e vfio: selftests: Test basic VFIO and IOMMUFD integration
Add a vfio test suite which verifies that userspace can bind and unbind
devices, allocate I/O address space, and attach a device to an IOMMU
domain using the cdev + IOMMUfd VFIO interface.

Signed-off-by: Josh Hilke <jrhilke@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-5-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:02 -06:00
David Matlack
16eadd7c12 vfio: selftests: Introduce vfio_pci_device_test
Introduce a basic VFIO selftest called vfio_pci_device_test to
demonstrate the functionality of the VFIO selftest library and provide
some test coverage of basic VFIO operations, including:

 - Mapping and unmapping DMA
 - Mapping and unmapping BARs
 - Enabling, triggering, and disabling MSI and MSI-x
 - Reading and writing to PCI config space

This test should work with most PCI devices, as long as they are bound
to vfio-pci.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-4-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:02 -06:00
David Matlack
19faf6fd96 vfio: selftests: Add a helper library for VFIO selftests
Add a basic helper library to be used by VFIO selftests.

The basic unit of the library is struct vfio_pci_device, which
represents a single PCI device that is bound to the vfio-pci driver. The
library currently only supports a single device per group and container,
and VFIO IOMMU types.

The code in this library was heavily based on prior work done by
Raghavendra Rao Ananta <rananta@google.com>, and the VFIO_ASSERT*()
macros were written by Vipin Sharma <vipinsh@google.com>.

Separate that Makefile rules for building the library into a separate
script so that the library can be built by and linked into KVM selftests
in a subsequent commit.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-3-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:01 -06:00
David Matlack
292e9ee22b selftests: Create tools/testing/selftests/vfio
Create the directory tools/testing/selftests/vfio with a stub Makefile
and hook it up to the top-level selftests Makefile.

This directory will be used in subsequent commits to host selftests for
the VFIO subsystem.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-2-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-08-27 12:14:01 -06:00