[PATCH v4 i-g-t 0/6] PCI driver helpers and xe-vfio-pci FLR improvement

[Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>]

This series improves PCI driver management infrastructure in IGT
and updates the xe_sriov_flr test to rely on xe-vfio-pci FLR semantics.

It introduces generic PCI driver helpers for driver_override handling
and explicit bind/unbind operations.
Adds a small SR-IOV utility to resolve VF PCI slot addresses.
Fixes igt_kmod PCI bind/unbind logic to correctly handle module vs driver
name mismatches (e.g. xe_vfio_pci vs xe-vfio-pci), marking those helpers
as deprecated in favor of driver-level APIs.

The xe_sriov_flr test is updated to attach VFs to xe-vfio-pci
before initiating FLR, allowing the test to wait for FLR completion
via the driver.

V4 -> V3:
- Clarify igt_pci_get_bound_driver_name() doc that driver/driver_len
  are optional (NULL/0 valid when only checking bound/unbound) (Lukasz)
- Drop patch checking IOMMU group presence before loading xe-vfio-pci
  (Lukasz)

V3 -> V2:
- Add --wait-flr-ms option to configure post FLR sleep time
- Add --no-xe-vfio-pci option to skip xe-vfio-pci load
- Skip xe-vfio-pci load/bind when IOMMU is off

V2 -> V1:
- Add igt_pci_get_bound_driver_name() to query the currently bound PCI
  driver via the /sys/bus/pci/devices/<BDF>/driver symlink.
- Extend igt_pci_bind_driver_override() and
  igt_pci_unbind_driver_override() with a timeout_ms parameter so callers
  can wait for bind/unbind to actually complete, instead of relying on
  drivers_probe write success. drivers_probe only initiates an async
  reprobe, so a successful write does not mean bind/unbind succeeded -
  verify the effective bound driver with a timeout.
- Unbind VFs only if they were successfully bound.

Marcin Bernatowicz (6):
  lib/igt_sriov_device: Add helper to get VF PCI slot address
  lib/igt_pci: Add generic PCI driver override and bind/unbind helpers
  tests/intel/xe_sriov_flr: Attach VFs to xe-vfio-pci before initiating
    FLR
  lib/igt_kmod: Fix PCI bind/unbind for module/driver name mismatch
  tests/intel/xe_sriov_flr: Add --wait-flr-ms option
  tests/intel/xe_sriov_flr: Add --no-xe-vfio-pci option

 lib/igt_kmod.c             |  90 ++++++----
 lib/igt_pci.c              | 354 +++++++++++++++++++++++++++++++++++++
 lib/igt_pci.h              |  13 +-
 lib/igt_sriov_device.c     |  25 +++
 lib/igt_sriov_device.h     |   1 +
 tests/intel/xe_sriov_flr.c | 110 +++++++++++-
 6 files changed, 551 insertions(+), 42 deletions(-)

-- 
2.43.0