Re: [PATCH v6 00/30] VF migration redesign

[Matthew Brost <matthew.brost@intel.com>]

On Mon, Oct 06, 2025 at 05:20:08PM -0700, Niranjana Vishwanathapura wrote:
> On Mon, Oct 06, 2025 at 04:10:08AM -0700, Matthew Brost wrote:
> > Rather than modifying buffers in place using GGTT addresses during VF
> > migration, this approach relies on the submission backend's stop/start
> > mechanism to issue fixups. The patch titled "Document GuC Submission
> > Backend" provides a detailed explanation of the design.
> 
> I don't see this "Document GuC Submission Backend" patch in this version
> of patch series. I saw that in older version of the series, but there
> also, I think it was missing xe_guc_submit.rst file.
> 

I think that patch will be posted in a standalone patch in a follow up.

Matt

> Niranjana
> 
> > 
> > Testing was performed using an out-of-tree PF/VFIO driver with manual
> > triggering of VF migration while IGT test cases are running.
> > 
> > IGT test cases:
> > 
> > - A new series [1] that exercises active contexts, job resubmission, and
> >  compressd memory.
> > 
> > - A new test [2] that actively creates / destroys queue on each
> >  submission
> > 
> > - xe_exec_threads basic sections, which test context registration loss,
> >  schedule enable loss, and job resubmission.
> > 
> > - xe_exec_threads balancer sections, which follow the same flows as the
> >  basic sections but include a work queue (GGTT address shift).
> > 
> > - xe_exec_threads compute mode user pointer invalidation sections, which
> >  exercise the same flow as the basic sections, plus replaying
> >  suspend/resume flows.
> > 
> > All code paths in "Replay GuC submission state on pause/unpause" that
> > replay state have been manually verified via debug messages "Add debug
> > prints for GuC replaying state during VF recovery".
> > 
> > v2:
> > - Fix lockdep splat
> > - Fix checkpatch
> > - Fix PTL issue with LRC W/A buffer
> > - Fix race creating / destroying queues across migration exposed by [2]
> > - Include a version of Satya's patches in [3] which enable CCS save /
> >   restore across VF migration /w GGTT shift
> > v3:
> > - Address feedback
> > - Fix preempt fence mode deadlock /w work queues + VF recovery (Testing)
> > - Add NULL checks to scratch LRC allocation
> > v4:
> > - Fix CI failure
> > - Remove config lock
> > v5:
> > - Fix CI failures related to lockdep
> > - Address various comments
> > v6:
> > - Rebase for CI
> > 
> > Matt
> > 
> > Matthew Brost (28):
> >  drm/xe: Add NULL checks to scratch LRC allocation
> >  drm/xe: Save off position in ring in which a job was programmed
> >  drm/xe/guc: Track pending-enable source in submission state
> >  drm/xe: Track LR jobs in DRM scheduler pending list
> >  drm/xe: Don't change LRC ring head on job resubmission
> >  drm/xe: Make LRC W/A scratch buffer usage consistent
> >  drm/xe/vf: Add xe_gt_recovery_pending helper
> >  drm/xe/vf: Make VF recovery run on per-GT worker
> >  drm/xe/vf: Abort H2G sends during VF post-migration recovery
> >  drm/xe/vf: Remove memory allocations from VF post migration recovery
> >  drm/xe/vf: Close multi-GT GGTT shift race
> >  drm/xe/vf: Teardown VF post migration worker on driver unload
> >  drm/xe/vf: Don't allow GT reset to be queued during VF post migration
> >    recovery
> >  drm/xe/vf: Wakeup in GuC backend on VF post migration recovery
> >  drm/xe/vf: Avoid indefinite blocking in preempt rebind worker for VFs
> >    supporting migration
> >  drm/xe/vf: Use GUC_HXG_TYPE_EVENT for GuC context register
> >  drm/xe/vf: Flush and stop CTs in VF post migration recovery
> >  drm/xe/vf: Reset TLB invalidations during VF post migration recovery
> >  drm/xe/vf: Kickstart after resfix in VF post migration recovery
> >  drm/xe/vf: Start CTs before resfix VF post migration recovery
> >  drm/xe/vf: Abort VF post migration recovery on failure
> >  drm/xe/vf: Replay GuC submission state on pause / unpause
> >  drm/xe: Move queue init before LRC creation
> >  drm/xe/vf: Add debug prints for GuC replaying state during VF recovery
> >  drm/xe/vf: Workaround for race condition in GuC firmware during VF
> >    pause
> >  drm/xe/vf: Use primary GT ordered work queue on media GT on PTL VF
> >  drm/xe/vf: Ensure media GT VF recovery runs after primary GT on PTL
> >  drm/xe/vf: Rebase CCS save/restore BB GGTT addresses
> > 
> > Satyanarayana K V P (2):
> >  drm/xe: Use PPGTT addresses for TLB invalidation to avoid GGTT fixups
> >  drm/xe/guc: Increase wait timeout to 2sec after BUSY reply from GuC
> > 
> > drivers/gpu/drm/xe/xe_device_types.h         |   5 +
> > drivers/gpu/drm/xe/xe_exec.c                 |  12 +-
> > drivers/gpu/drm/xe/xe_exec_queue.c           |  64 +--
> > drivers/gpu/drm/xe/xe_exec_queue.h           |   2 -
> > drivers/gpu/drm/xe/xe_exec_queue_types.h     |   3 +
> > drivers/gpu/drm/xe/xe_execlist.c             |   2 +-
> > drivers/gpu/drm/xe/xe_gpu_scheduler.c        |  14 +
> > drivers/gpu/drm/xe/xe_gpu_scheduler.h        |   2 +
> > drivers/gpu/drm/xe/xe_gt.c                   |  28 +-
> > drivers/gpu/drm/xe/xe_gt.h                   |  15 +-
> > drivers/gpu/drm/xe/xe_gt_sriov_vf.c          | 458 +++++++++++++----
> > drivers/gpu/drm/xe/xe_gt_sriov_vf.h          |  13 +-
> > drivers/gpu/drm/xe/xe_gt_sriov_vf_types.h    |  33 +-
> > drivers/gpu/drm/xe/xe_guc.c                  |   4 +-
> > drivers/gpu/drm/xe/xe_guc_ct.c               | 121 +++--
> > drivers/gpu/drm/xe/xe_guc_ct.h               |  11 +
> > drivers/gpu/drm/xe/xe_guc_exec_queue_types.h |  15 +
> > drivers/gpu/drm/xe/xe_guc_submit.c           | 486 +++++++++++++++----
> > drivers/gpu/drm/xe/xe_guc_submit.h           |   5 +-
> > drivers/gpu/drm/xe/xe_lrc.c                  |  15 +-
> > drivers/gpu/drm/xe/xe_lrc.h                  |  10 +
> > drivers/gpu/drm/xe/xe_memirq.c               |  48 +-
> > drivers/gpu/drm/xe/xe_memirq.h               |   2 +
> > drivers/gpu/drm/xe/xe_migrate.c              |  28 +-
> > drivers/gpu/drm/xe/xe_pci.c                  |   6 +-
> > drivers/gpu/drm/xe/xe_pci_types.h            |   1 +
> > drivers/gpu/drm/xe/xe_preempt_fence.c        |  11 +
> > drivers/gpu/drm/xe/xe_ring_ops.c             |  23 +-
> > drivers/gpu/drm/xe/xe_sched_job_types.h      |   9 +
> > drivers/gpu/drm/xe/xe_sriov_vf.c             | 240 ---------
> > drivers/gpu/drm/xe/xe_sriov_vf.h             |   1 -
> > drivers/gpu/drm/xe/xe_sriov_vf_ccs.c         |  28 ++
> > drivers/gpu/drm/xe/xe_sriov_vf_ccs.h         |   1 +
> > drivers/gpu/drm/xe/xe_sriov_vf_types.h       |   4 -
> > drivers/gpu/drm/xe/xe_tile.c                 |   2 +-
> > drivers/gpu/drm/xe/xe_tile_sriov_vf.c        |  30 +-
> > drivers/gpu/drm/xe/xe_tile_sriov_vf.h        |   2 +-
> > drivers/gpu/drm/xe/xe_tile_sriov_vf_types.h  |  23 +
> > drivers/gpu/drm/xe/xe_vm.c                   |  26 +-
> > drivers/gpu/drm/xe/xe_vram.c                 |   6 +-
> > 40 files changed, 1250 insertions(+), 559 deletions(-)
> > create mode 100644 drivers/gpu/drm/xe/xe_tile_sriov_vf_types.h
> > 
> > -- 
> > 2.34.1
> >