Re: [PATCH i-g-t 2/4] tests/intel/xe_sriov_vfio: Add dynamic bind-unbind-vfs subtest

["Laguna, Lukasz" <lukasz.laguna@intel.com>]

On 3/18/2026 17:14, Marcin Bernatowicz wrote:
> For each supported numvfs-N configuration, enable N VFs and
> bind/unbind each VF to xe-vfio-pci through driver_override.
>
> Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
> Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
> Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
> Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
> Cc: Lukasz Laguna <lukasz.laguna@intel.com>
> ---
>   tests/intel/xe_sriov_vfio.c | 169 ++++++++++++++++++++++++++++++++++++
>   1 file changed, 169 insertions(+)
>
> diff --git a/tests/intel/xe_sriov_vfio.c b/tests/intel/xe_sriov_vfio.c
> index 2fe0137e1..a2b2959e2 100644
> --- a/tests/intel/xe_sriov_vfio.c
> +++ b/tests/intel/xe_sriov_vfio.c
> @@ -5,9 +5,13 @@
>   
>   #include <ctype.h>
>   #include <dirent.h>
> +#include <fcntl.h>
>   
> +#include "drmtest.h"
>   #include "igt_core.h"
>   #include "igt_kmod.h"
> +#include "igt_pci.h"
> +#include "igt_sriov_device.h"
>   
>   /**
>    * TEST: xe_sriov_vfio
> @@ -22,13 +26,23 @@
>    *
>    * SUBTEST: unload-xe-vfio-pci
>    * Description: Attempt to unload xe_vfio_pci module (skips if busy).
> + *
> + * SUBTEST: bind-unbind-vfs
> + * Description: Enable VFs and bind/unbind each one to xe-vfio-pci via driver_override.
>    */
>   
>   IGT_TEST_DESCRIPTION("Xe SR-IOV VFIO tests (xe-vfio-pci)");
>   
> +#define DRIVER_OVERRIDE_TIMEOUT_MS 200
> +
>   static const char *XE_VFIO_PCI_MOD = "xe_vfio_pci";
>   static const char *XE_VFIO_PCI_DRV = "xe-vfio-pci";
>   
> +static int pf_fd = -1;
> +static bool autoprobe;
> +static bool xe_vfio_loaded_initially;
> +static bool restore_xe_vfio_on_exit;
> +
>   static bool pci_driver_has_any_bound_devices(const char *driver)
>   {
>   	char path[PATH_MAX];
> @@ -54,8 +68,143 @@ static bool pci_driver_has_any_bound_devices(const char *driver)
>   	return false;
>   }
>   
> +static void assert_bound_driver_is(const char *pci_slot, const char *expected)

I think it would be better to have two helpers: assert_driver_bound() 
and assert_driver_unbound()

> +{
> +	char bound[64];
> +	int ret;
> +
> +	ret = igt_pci_get_bound_driver_name(pci_slot, bound, sizeof(bound));
> +	igt_assert_f(ret >= 0, "Failed to read bound driver for %s (%d)\n", pci_slot, ret);
> +
> +	if (!expected) {
> +		igt_assert_f(ret == 0, "Expected %s to be unbound, but is bound to %s\n",
> +			     pci_slot, bound);
> +		return;
> +	}
> +
> +	igt_assert_f(ret > 0, "Expected %s to be bound to %s, but it is unbound\n",
> +		     pci_slot, expected);
> +	igt_assert_f(!strcmp(bound, expected), "Expected %s to be bound to %s, got %s\n",
> +		     pci_slot, expected, bound);
> +}
> +
> +static char *vf_pci_slot_alloc(unsigned int vf_id)
> +{
> +	char *slot = igt_sriov_get_vf_pci_slot_alloc(pf_fd, vf_id);
> +
> +	igt_assert_f(slot, "Failed to get VF%u PCI slot\n", vf_id);
> +	return slot;
> +}
> +
> +static void vf_bind_override(unsigned int vf_id, const char *driver)
> +{
> +	char *slot = vf_pci_slot_alloc(vf_id);
> +	int ret;
> +
> +	ret = igt_pci_bind_driver_override(slot, driver, DRIVER_OVERRIDE_TIMEOUT_MS);
> +	igt_assert_f(ret == 0, "bind %s (VF%u) to %s failed (%d)\n", slot, vf_id, driver, ret);
> +	assert_bound_driver_is(slot, driver);
> +
> +	free(slot);
> +}
> +
> +static void vf_unbind_override(unsigned int vf_id)
> +{
> +	char *slot = vf_pci_slot_alloc(vf_id);
> +	int ret;
> +
> +	ret = igt_pci_unbind_driver_override(slot, DRIVER_OVERRIDE_TIMEOUT_MS);
> +	igt_assert_f(ret == 0, "unbind %s (VF%u) failed (%d)\n", slot, vf_id, ret);
> +	assert_bound_driver_is(slot, NULL);
> +
> +	free(slot);
> +}
> +
> +static void bind_unbind_vfs(unsigned int num_vfs)
> +{
> +	igt_sriov_disable_driver_autoprobe(pf_fd);
> +	igt_sriov_enable_vfs(pf_fd, num_vfs);
> +
> +	igt_require_f(!igt_pci_system_reinit(), "Failed to refresh PCI state\n");
> +
> +	igt_sriov_enable_driver_autoprobe(pf_fd);
> +
> +	for (unsigned int vf_id = 1; vf_id <= num_vfs; vf_id++) {
> +		vf_unbind_override(vf_id);

Why unbind here?

> +		vf_bind_override(vf_id, XE_VFIO_PCI_DRV);
> +		vf_unbind_override(vf_id);
> +	}
> +
> +	igt_sriov_disable_vfs(pf_fd);
> +}
> +
> +static void open_pf(void)
> +{
> +	int fd;
> +
> +	if (pf_fd >= 0)
> +		return;
> +
> +	fd = drm_open_driver(DRIVER_XE);
> +	igt_assert_fd(fd);
> +
> +	if (!igt_sriov_is_pf(fd)) {
> +		drm_close_driver(fd);
> +		igt_skip("Xe device is not an SR-IOV PF\n");
> +	}
> +
> +	if (igt_sriov_get_enabled_vfs(fd) != 0) {
> +		drm_close_driver(fd);
> +		igt_skip("VFs must be disabled before running this test\n");
> +	}
> +
> +	autoprobe = igt_sriov_is_driver_autoprobe_enabled(fd);
> +	pf_fd = fd;
> +}
> +
> +static void cleanup_pf(void)
> +{
> +	if (pf_fd < 0)
> +		return;
> +
> +	igt_sriov_disable_vfs(pf_fd);
> +	igt_abort_on_f(igt_sriov_get_enabled_vfs(pf_fd) > 0, "Failed to disable VF(s)\n");
> +	autoprobe ? igt_sriov_enable_driver_autoprobe(pf_fd) :
> +		   igt_sriov_disable_driver_autoprobe(pf_fd);
> +	igt_abort_on_f(autoprobe != igt_sriov_is_driver_autoprobe_enabled(pf_fd),
> +		       "Failed to restore sriov_drivers_autoprobe value\n");
> +	drm_close_driver(pf_fd);
> +	pf_fd = -1;
> +}
> +
> +static void restore_xe_vfio_module(void)
> +{
> +	if (!restore_xe_vfio_on_exit)

If you go with one subtest (load-unload) approach, then I think we 
should always leave the environment in the original state, so this 
variable would not be needed.

> +		return;
> +
> +	if (xe_vfio_loaded_initially) {
> +		igt_abort_on_f(igt_kmod_load(XE_VFIO_PCI_MOD, NULL),
> +			       "Failed to restore %s load state\n",
> +			       XE_VFIO_PCI_MOD);
> +		igt_abort_on_f(!igt_kmod_is_loaded(XE_VFIO_PCI_MOD),
> +			       "%s should be loaded after cleanup\n",
> +			       XE_VFIO_PCI_MOD);
> +	} else if (igt_kmod_is_loaded(XE_VFIO_PCI_MOD)) {
> +		igt_abort_on_f(igt_kmod_unload(XE_VFIO_PCI_MOD),
> +			       "Failed to unload %s\n", XE_VFIO_PCI_MOD);

I think it should be consistent - "Failed to restore %s load state".

> +		igt_abort_on_f(igt_kmod_is_loaded(XE_VFIO_PCI_MOD),
> +			       "%s still loaded\n", XE_VFIO_PCI_MOD);

If it's an abort I would say something like "Failed to do sth" or "Can't 
do sth"

Maybe use err variable, and at the end use one igt_abort_on_f(err, 
"Failed to restore %s module load state") ?

> +	}
> +
> +	restore_xe_vfio_on_exit = false;
> +}
> +
>   int igt_main()
>   {
> +	igt_fixture() {
> +		xe_vfio_loaded_initially = igt_kmod_is_loaded(XE_VFIO_PCI_MOD);
> +	}
> +
>   	igt_describe("Attempt to load xe_vfio_pci module.");
>   	igt_subtest("load-xe-vfio-pci") {
>   		int ret;
> @@ -85,4 +234,24 @@ int igt_main()
>   		igt_assert_f(!igt_kmod_is_loaded(XE_VFIO_PCI_MOD), "%s still loaded\n",
>   			     XE_VFIO_PCI_MOD);
>   	}
> +
> +	igt_describe("Enable VFs and bind/unbind each one to xe-vfio-pci via driver_override.");
> +	igt_subtest_with_dynamic("bind-unbind-vfs") {
> +		igt_skip_on_f(igt_kmod_load(XE_VFIO_PCI_MOD, NULL),
> +			      "Failed to load %s\n", XE_VFIO_PCI_MOD);
> +		restore_xe_vfio_on_exit = true;
> +
> +		open_pf();
> +
> +		for_each_sriov_num_vfs(pf_fd, num_vfs) {
> +			igt_dynamic_f("numvfs-%u", num_vfs) {
> +				bind_unbind_vfs(num_vfs);
> +			}
> +		}
> +	}
> +
> +	igt_fixture() {
> +		cleanup_pf();
> +		restore_xe_vfio_module();
> +	}
>   }