Re: [PATCH v2 6/6] vfio: selftests: Add tests to validate SR-IOV UAPI

[David Matlack <dmatlack@google.com>]

On 2025-12-10 06:14 PM, Raghavendra Rao Ananta wrote:
> Add a selfttest, vfio_pci_sriov_uapi_test.c, to validate the
> SR-IOV UAPI, including the following cases, iterating over
> all the IOMMU modes currently supported:
>  - Setting correct/incorrect/NULL tokens during device init.
>  - Close the PF device immediately after setting the token.
>  - Change/override the PF's token after device init.
> 
> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> ---
>  tools/testing/selftests/vfio/Makefile         |   1 +
>  .../selftests/vfio/vfio_pci_sriov_uapi_test.c | 215 ++++++++++++++++++
>  2 files changed, 216 insertions(+)
>  create mode 100644 tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c
> 
> diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
> index 3c796ca99a509..f00a63902fbfb 100644
> --- a/tools/testing/selftests/vfio/Makefile
> +++ b/tools/testing/selftests/vfio/Makefile
> @@ -4,6 +4,7 @@ TEST_GEN_PROGS += vfio_iommufd_setup_test
>  TEST_GEN_PROGS += vfio_pci_device_test
>  TEST_GEN_PROGS += vfio_pci_device_init_perf_test
>  TEST_GEN_PROGS += vfio_pci_driver_test
> +TEST_GEN_PROGS += vfio_pci_sriov_uapi_test
>  
>  TEST_FILES += scripts/cleanup.sh
>  TEST_FILES += scripts/lib.sh
> diff --git a/tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c b/tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c
> new file mode 100644
> index 0000000000000..4c2951d6e049c
> --- /dev/null
> +++ b/tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c
> @@ -0,0 +1,215 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <stdlib.h>
> +#include <sys/ioctl.h>
> +#include <linux/limits.h>
> +
> +#include <libvfio.h>
> +
> +#include "../kselftest_harness.h"
> +
> +#define UUID_1 "52ac9bff-3a88-4fbd-901a-0d767c3b6c97"
> +#define UUID_2 "88594674-90a0-47a9-aea8-9d9b352ac08a"
> +
> +static const char *pf_dev_bdf;

nit: I think you could simplify some of the names in this file. This
code isn't in a library so the names dont' have to be globally unique
and quite so long.

  s/pf_dev_bdf/pf_bdf/
  s/vf_dev_bdf/vf_bdf/
  s/pf_device/pf/
  s/vf_device/vf/
  s/test_vfio_pci_container_setup/container_setup/
  s/test_vfio_pci_iommufd_setup/iommufd_setup/
  s/test_vfio_pci_device_init/device_init/
  s/test_vfio_pci_device_cleanup/device_cleanup/

Feel free to ignore this though if you think it makes the names too
terse.

> +
> +static int test_vfio_pci_container_setup(struct vfio_pci_device *device,
> +					 const char *bdf,
> +					 const char *vf_token)
> +{
> +	vfio_pci_group_setup(device, bdf);
> +	vfio_container_set_iommu(device);
> +	__vfio_pci_group_get_device_fd(device, bdf, vf_token);
> +
> +	/* The device fd will be -1 in case of mismatched tokens */
> +	return (device->fd < 0);
> +}
> +
> +static int test_vfio_pci_iommufd_setup(struct vfio_pci_device *device,
> +				       const char *bdf, const char *vf_token)
> +{
> +	vfio_pci_iommufd_cdev_open(device, bdf);
> +	return __vfio_device_bind_iommufd(device->fd,
> +					  device->iommu->iommufd, vf_token);
> +}
> +
> +static struct vfio_pci_device *test_vfio_pci_device_init(const char *bdf,
> +							 struct iommu *iommu,
> +							 const char *vf_token,
> +							 int *out_ret)
> +{
> +	struct vfio_pci_device *device;
> +
> +	device = calloc(1, sizeof(*device));
> +	VFIO_ASSERT_NOT_NULL(device);
> +
> +	device->iommu = iommu;
> +	device->bdf = bdf;

Can you put this in a helper exposed by vfio_pci_device.h? e.g.
vfio_pci_device_alloc()

> +
> +	if (iommu->mode->container_path)
> +		*out_ret = test_vfio_pci_container_setup(device, bdf, vf_token);
> +	else
> +		*out_ret = test_vfio_pci_iommufd_setup(device, bdf, vf_token);
> +
> +	return device;
> +}
> +
> +static void test_vfio_pci_device_cleanup(struct vfio_pci_device *device)
> +{
> +	if (device->fd > 0)
> +		VFIO_ASSERT_EQ(close(device->fd), 0);
> +
> +	if (device->group_fd)
> +		VFIO_ASSERT_EQ(close(device->group_fd), 0);
> +
> +	free(device);
> +}
> +
> +FIXTURE(vfio_pci_sriov_uapi_test) {
> +	char vf_dev_bdf[16];
> +	char vf_driver[32];
> +	bool sriov_drivers_autoprobe;
> +};
> +
> +FIXTURE_SETUP(vfio_pci_sriov_uapi_test)
> +{
> +	int nr_vfs;
> +	int ret;
> +
> +	nr_vfs = sysfs_get_sriov_totalvfs(pf_dev_bdf);
> +	if (nr_vfs < 0)
> +		SKIP(return, "SR-IOV may not be supported by the device\n");

Should this be <= 0?

And replace "the device" with the BDF.

> +
> +	nr_vfs = sysfs_get_sriov_numvfs(pf_dev_bdf);
> +	if (nr_vfs != 0)
> +		SKIP(return, "SR-IOV already configured for the PF\n");

Let's print the BDF and nr_vfs for the user.

> +
> +	self->sriov_drivers_autoprobe =
> +		sysfs_get_sriov_drivers_autoprobe(pf_dev_bdf);
> +	if (self->sriov_drivers_autoprobe)
> +		sysfs_set_sriov_drivers_autoprobe(pf_dev_bdf, 0);
> +
> +	/* Export only one VF for testing */

s/Export/Create/

> +	sysfs_set_sriov_numvfs(pf_dev_bdf, 1);
> +
> +	sysfs_get_sriov_vf_bdf(pf_dev_bdf, 0, self->vf_dev_bdf);
> +	if (sysfs_get_driver(self->vf_dev_bdf, self->vf_driver) == 0)
> +		sysfs_unbind_driver(self->vf_dev_bdf, self->vf_driver);

This should be impossible since we disabled autoprobing.

> +	sysfs_bind_driver(self->vf_dev_bdf, "vfio-pci");

Some devices also require setting driver_override to "vfio-pci" as well
so the device can be bound to vfio-pci. Let's just do that
unconditionally.

> +}
> +
> +FIXTURE_TEARDOWN(vfio_pci_sriov_uapi_test)
> +{
> +	sysfs_unbind_driver(self->vf_dev_bdf, "vfio-pci");
> +	sysfs_bind_driver(self->vf_dev_bdf, self->vf_driver);
> +	sysfs_set_sriov_numvfs(pf_dev_bdf, 0);
> +	sysfs_set_sriov_drivers_autoprobe(pf_dev_bdf,
> +					  self->sriov_drivers_autoprobe);
> +}
> +
> +FIXTURE_VARIANT(vfio_pci_sriov_uapi_test) {
> +	const char *iommu_mode;
> +	char *vf_token;
> +};
> +
> +#define FIXTURE_VARIANT_ADD_IOMMU_MODE(_iommu_mode, _name, _vf_token)		\
> +FIXTURE_VARIANT_ADD(vfio_pci_sriov_uapi_test, _iommu_mode ## _ ## _name) {	\
> +	.iommu_mode = #_iommu_mode,						\
> +	.vf_token = (_vf_token),						\
> +}
> +
> +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(same_uuid, UUID_1);
> +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(diff_uuid, UUID_2);
> +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(null_uuid, NULL);
> +
> +/*
> + * PF's token is always set with UUID_1 and VF's token is rotated with
> + * various tokens (including UUID_1 and NULL).
> + * This asserts if the VF device is successfully created for a match
> + * in the token or actually fails during a mismatch.
> + */
> +#define ASSERT_VF_CREATION(_ret) do {					\
> +	if (!variant->vf_token || strcmp(UUID_1, variant->vf_token)) {	\
> +		ASSERT_NE((_ret), 0);					\
> +	} else {							\
> +		ASSERT_EQ((_ret), 0);					\
> +	}								\
> +} while (0)
> +
> +/*
> + * Validate if the UAPI handles correctly and incorrectly set token on the VF.
> + */
> +TEST_F(vfio_pci_sriov_uapi_test, init_token_match)
> +{
> +	struct vfio_pci_device *pf_device;
> +	struct vfio_pci_device *vf_device;
> +	struct iommu *iommu;
> +	int ret;
> +
> +	iommu = iommu_init(variant->iommu_mode);
> +	pf_device = test_vfio_pci_device_init(pf_dev_bdf, iommu, UUID_1, &ret);
> +	vf_device = test_vfio_pci_device_init(self->vf_dev_bdf, iommu,
> +					      variant->vf_token, &ret);
> +
> +	ASSERT_VF_CREATION(ret);
> +
> +	test_vfio_pci_device_cleanup(vf_device);
> +	test_vfio_pci_device_cleanup(pf_device);
> +	iommu_cleanup(iommu);
> +}
> +
> +/*
> + * After setting a token on the PF, validate if the VF can still set the
> + * expected token.
> + */
> +TEST_F(vfio_pci_sriov_uapi_test, pf_early_close)
> +{
> +	struct vfio_pci_device *pf_device;
> +	struct vfio_pci_device *vf_device;
> +	struct iommu *iommu;
> +	int ret;
> +
> +	iommu = iommu_init(variant->iommu_mode);
> +	pf_device = test_vfio_pci_device_init(pf_dev_bdf, iommu, UUID_1, &ret);
> +	test_vfio_pci_device_cleanup(pf_device);
> +
> +	vf_device = test_vfio_pci_device_init(self->vf_dev_bdf, iommu,
> +					      variant->vf_token, &ret);
> +
> +	ASSERT_VF_CREATION(ret);
> +
> +	test_vfio_pci_device_cleanup(vf_device);
> +	iommu_cleanup(iommu);
> +}
> +
> +/*
> + * After PF device init, override the existing token and validate if the newly
> + * set token is the one that's active.
> + */
> +TEST_F(vfio_pci_sriov_uapi_test, override_token)
> +{
> +	struct vfio_pci_device *pf_device;
> +	struct vfio_pci_device *vf_device;
> +	struct iommu *iommu;
> +	int ret;
> +
> +	iommu = iommu_init(variant->iommu_mode);
> +	pf_device = test_vfio_pci_device_init(pf_dev_bdf, iommu, UUID_2, &ret);
> +	vfio_device_set_vf_token(pf_device->fd, UUID_1);
> +
> +	vf_device = test_vfio_pci_device_init(self->vf_dev_bdf, iommu,
> +					      variant->vf_token, &ret);
> +
> +	ASSERT_VF_CREATION(ret);
> +
> +	test_vfio_pci_device_cleanup(vf_device);
> +	test_vfio_pci_device_cleanup(pf_device);
> +	iommu_cleanup(iommu);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +	pf_dev_bdf = vfio_selftests_get_bdf(&argc, argv);
> +	return test_harness_run(argc, argv);
> +}
> -- 
> 2.52.0.239.gd5f0c6e74e-goog
>