[Intel-xe] [PATCH v2 0/4] drm/xe: Support optional pinning of userptr pages

[Thomas Hellström]

This series adds a flag at VM_BIND time to pin the memory backing a VMA.
Initially this is needed for long-running workloads on hardware that
neither support mid-thread preemption nor pagefaults, since without it
the userptr MMU notifier will wait for preemption until preemption times
out.

Moving forward this could be supported also for bo-backed VMAs given
a proper accounting takes place. A sysadmin could then optionally configure
a system to be optimized for dealing with a single GPU application
at a time.

The series will be followed up with an igt series to exercise the uAPI.

v2:
- Address review comments by Matthew Brost.

Thomas Hellström (4):
  drm/xe/vm: Use onion unwind for xe_vma_userptr_pin_pages()
  drm/xe/vm: Implement userptr page pinning
  drm/xe/vm: Perform accounting of userptr pinned pages
  drm/xe/uapi: Support pinning of userptr vmas

 drivers/gpu/drm/xe/xe_vm.c       | 194 ++++++++++++++++++++++++-------
 drivers/gpu/drm/xe/xe_vm.h       |   9 ++
 drivers/gpu/drm/xe/xe_vm_types.h |  14 +++
 include/uapi/drm/xe_drm.h        |  18 +++
 4 files changed, 190 insertions(+), 45 deletions(-)

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2.41.0