Re: [PATCH v3 i-g-t 3/7] tests/intel/xe_sriov_flr: Attach VFs to xe-vfio-pci before initiating FLR

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

On 2/4/2026 17:32, Marcin Bernatowicz wrote:
> Attach all VFs to the xe-vfio-pci driver before running the FLR scenario.
> This allows the test to rely on xe-vfio-pci’s FLR wait handling, which is
> triggered when writing to the VF reset sysfs attribute.
>
> Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
> Suggested-by: Michał Winiarski <michal.winiarski@intel.com>
> Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
> Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
> Cc: Lukasz Laguna <lukasz.laguna@intel.com>

Reviewed-by: Lukasz Laguna <lukasz.laguna@intel.com>

>
> ---
> v2:
> - Unbind VFs only if they were successfully bound.
>
> ---
>   tests/intel/xe_sriov_flr.c | 65 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 65 insertions(+)
>
> diff --git a/tests/intel/xe_sriov_flr.c b/tests/intel/xe_sriov_flr.c
> index 12989d0f5..2f6b24cf0 100644
> --- a/tests/intel/xe_sriov_flr.c
> +++ b/tests/intel/xe_sriov_flr.c
> @@ -9,6 +9,8 @@
>   #include "drmtest.h"
>   #include "igt_core.h"
>   #include "igt_device.h"
> +#include "igt_kmod.h"
> +#include "igt_pci.h"
>   #include "igt_sriov_device.h"
>   #include "intel_chipset.h"
>   #include "intel_vram.h"
> @@ -57,6 +59,8 @@ static const char STOP_REASON_ABORT[] = "ABORT";
>   static const char STOP_REASON_FAIL[]  = "FAIL";
>   static const char STOP_REASON_SKIP[]  = "SKIP";
>   
> +#define DRIVER_OVERRIDE_TIMEOUT_MS 200
> +
>   static struct g_mmio {
>   	struct xe_mmio *mmio;
>   	unsigned int num_vfs;
> @@ -276,6 +280,47 @@ static void subchecks_report_results(struct subcheck *checks, int num_checks)
>   	igt_skip_on(skips == num_checks);
>   }
>   
> +static bool vf_bind_driver_override(int pf_fd, unsigned int vf_id,
> +				    const char *driver)
> +{
> +	char *slot = igt_sriov_get_vf_pci_slot_alloc(pf_fd, vf_id);
> +	int ret;
> +	char bound[64] = "none";
> +	int bound_ret;
> +
> +	igt_assert(slot);
> +	igt_assert(driver);
> +
> +	ret = igt_pci_bind_driver_override(slot, driver, DRIVER_OVERRIDE_TIMEOUT_MS);
> +	if (ret < 0) {
> +		bound_ret = igt_pci_get_bound_driver_name(slot, bound, sizeof(bound));
> +		if (bound_ret <= 0)
> +			snprintf(bound, sizeof(bound), "%s", "none");
> +
> +		igt_warn_on_f(true,
> +			      "bind %s (VF%u) to %s ret=%d (currently bound: %s)\n",
> +			      slot, vf_id, driver, ret, bound);
> +	}
> +
> +	free(slot);
> +
> +	return ret >= 0;
> +}
> +
> +static void vf_unbind_driver_override(int pf_fd, unsigned int vf_id)
> +{
> +	char *slot = igt_sriov_get_vf_pci_slot_alloc(pf_fd, vf_id);
> +	int ret;
> +
> +	igt_assert(slot);
> +
> +	ret = igt_pci_unbind_driver_override(slot, DRIVER_OVERRIDE_TIMEOUT_MS);
> +	igt_warn_on_f(ret < 0, "unbind %s (VF%u) driver_override ret=%d\n",
> +		      slot, vf_id, ret);
> +
> +	free(slot);
> +}
> +
>   /**
>    * flr_exec_strategy - Function pointer for FLR execution strategy
>    * @pf_fd: File descriptor for the Physical Function (PF).
> @@ -325,6 +370,8 @@ static void verify_flr(int pf_fd, int num_vfs, struct subcheck *checks,
>   {
>   	const int wait_flr_ms = 200;
>   	int i, vf_id, flr_vf_id = -1;
> +	bool xe_vfio_loaded;
> +	bool *vf_bound = NULL;
>   
>   	igt_sriov_disable_driver_autoprobe(pf_fd);
>   	igt_sriov_enable_vfs(pf_fd, num_vfs);
> @@ -335,6 +382,16 @@ static void verify_flr(int pf_fd, int num_vfs, struct subcheck *checks,
>   	if (igt_warn_on(igt_pci_system_reinit()))
>   		goto disable_vfs;
>   
> +	xe_vfio_loaded = igt_kmod_load("xe_vfio_pci", NULL) >= 0;
> +	if (xe_vfio_loaded) {
> +		vf_bound = calloc(num_vfs + 1, sizeof(*vf_bound));
> +		igt_assert(vf_bound);
> +
> +		igt_sriov_enable_driver_autoprobe(pf_fd);
> +		for (vf_id = 1; vf_id <= num_vfs; vf_id++)
> +			vf_bound[vf_id] = vf_bind_driver_override(pf_fd, vf_id, "xe-vfio-pci");
> +	}
> +
>   	init_mmio(pf_fd, num_vfs);
>   
>   	for (i = 0; i < num_checks; ++i)
> @@ -357,6 +414,14 @@ cleanup:
>   
>   	cleanup_mmio();
>   
> +	if (xe_vfio_loaded) {
> +		for (vf_id = 1; vf_id <= num_vfs; vf_id++)
> +			if (vf_bound && vf_bound[vf_id])
> +				vf_unbind_driver_override(pf_fd, vf_id);
> +	}
> +
> +	free(vf_bound);
> +
>   disable_vfs:
>   	igt_sriov_disable_vfs(pf_fd);
>