Re: [PATCH v7 8/8] vfio: selftests: Add tests to validate SR-IOV UAPI

[David Matlack <dmatlack@google.com>]

On 2026-04-02 05:30 PM, Raghavendra Rao Ananta wrote:

> +/* clang-format off */
> +FIXTURE(vfio_pci_sriov_uapi_test) {};
> +/* clang-format on */
> +
> +FIXTURE_SETUP(vfio_pci_sriov_uapi_test)
> +{
> +}
> +
> +FIXTURE_TEARDOWN(vfio_pci_sriov_uapi_test)
> +{
> +}

Please do iommu_init() iommu_cleanup() here to reduce code duplication
and as an added bonus you can drop the clang-format comments above.

> +static void vf_teardown(void)
> +{
> +	/* Destroy the VF only when the main/parent process exits. */
> +	if (getpid() != main_pid)
> +		return;

Is this because the child processes created by test_harness_run() to run
the TEST_F()s inherit the atexit() call? If so please clarify that in
the comment in more detail.

> +
> +	free(vf_bdf);
> +	sysfs_sriov_numvfs_set(pf_bdf, 0);
> +}
> +
> +static void vf_setup(void)
> +{
> +	char *vf_driver;
> +	int nr_vfs;
> +
> +	nr_vfs = sysfs_sriov_totalvfs_get(pf_bdf);
> +	if (nr_vfs <= 0)
> +		ksft_exit_skip("SR-IOV may not be supported by the PF: %s\n", pf_bdf);
> +
> +	nr_vfs = sysfs_sriov_numvfs_get(pf_bdf);
> +	if (nr_vfs != 0)
> +		ksft_exit_skip("SR-IOV already configured for the PF: %s\n", pf_bdf);
> +
> +	/* Create only one VF for testing */
> +	sysfs_sriov_numvfs_set(pf_bdf, 1);
> +
> +	/*
> +	 * Setup an exit handler to destroy the VF in case of failures
> +	 * during further setup at the end of the test run.
> +	 */
> +	main_pid = getpid();
> +	VFIO_ASSERT_EQ(atexit(vf_teardown), 0);
> +
> +	vf_bdf = sysfs_sriov_vf_bdf_get(pf_bdf, 0);
> +
> +	/*
> +	 * The VF inherits the driver from the PF.
> +	 * Ensure this is 'vfio-pci' before proceeding.
> +	 */
> +	vf_driver = sysfs_driver_get(vf_bdf);
> +	VFIO_ASSERT_NE(vf_driver, NULL);
> +	VFIO_ASSERT_EQ(strcmp(vf_driver, "vfio-pci"), 0);
> +	free(vf_driver);
> +
> +	printf("Created 1 VF (%s) under the PF: %s\n", vf_bdf, pf_bdf);

Do we actually need atexit()? This code can go into main and we can do
the VF cleanup before returning from main after test_harness_run()
returns. I don't think you even need to check the VF driver. If the VF
is not bound to vfio-pci then that will be caught by the test cases when
they call device_init(vf_bdf, ...).

That would make the logic more straightforward and get rid of the
main_pid stuff too.