[PATCH RFC v3 00/12] iommu: SVA and IOPF refactoring

[Lu Baolu]

Hi folks,

The former part of this series refactors the IOMMU SVA code by assigning
an SVA type of iommu_domain to a shared virtual address and replacing
sva_bind/unbind iommu ops with attach/detach_dev_pasid domain ops.

The latter part changes the existing I/O page fault handling framework
from only serving SVA to a generic one. Any driver or component could
handle the I/O page faults for its domain in its own way by installing
an I/O page fault handler.

This series overlaps with another series posted here [1]. For the
convenience of review, I included all relevant patches in this series.
We will solve the overlap problem later.

This series is also available on github here [2].

[1] https://lore.kernel.org/lkml/20220315050713.2000518-1-jacob.jun.pan@xxxxxxxxxxxxxxx/
[2] https://github.com/LuBaolu/intel-iommu/commits/iommu-sva-refactoring-v3

Please help review and suggest.

Best regards,
baolu

Change log:
v1:
 - https://lore.kernel.org/linux-iommu/20220320064030.2936936-1-baolu.lu@xxxxxxxxxxxxxxx/
 - Initial post.

v2:
 - https://lore.kernel.org/linux-iommu/20220329053800.3049561-1-baolu.lu@xxxxxxxxxxxxxxx/
 - Add sva domain life cycle management to avoid race between unbind and
   page fault handling.
 - Use a single domain for each mm.
 - Return a single sva handler for the same binding.
 - Add a new helper to meet singleton group requirement.
 - Rework the SVA domain allocation for arm smmu v3 driver and move the
   pasid_bit initialization to device probe.
 - Drop the patch "iommu: Handle IO page faults directly".
 - Add mmget_not_zero(mm) in SVA page fault handler.

v3:
 - Rework iommu_group_singleton_lockdown() by adding a flag to the group
   that positively indicates the group can never have more than one
   member, even after hot plug.
 - Abstract the data structs used for iommu sva in a separated patches to
   make it easier for review.
 - I still keep the RFC prefix in this series as above two significant
   changes need at least another round review to be finalized.
 - Several misc refinements.

Lu Baolu (12):
  iommu: Add pasid_bits field in struct dev_iommu
  iommu: Add a flag to indicate immutable singleton group
  iommu: Add attach/detach_dev_pasid domain ops
  iommu/sva: Basic data structures for SVA
  iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE support
  iommu/vt-d: Add SVA domain support
  arm-smmu-v3/sva: Add SVA domain support
  iommu/sva: Use attach/detach_pasid_dev in SVA interfaces
  iommu: Remove SVA related callbacks from iommu ops
  iommu: Prepare IOMMU domain for IOPF
  iommu: Per-domain I/O page fault handling
  iommu: Rename iommu-sva-lib.{c,h}

 include/linux/intel-iommu.h                   |   5 +-
 include/linux/iommu.h                         | 107 ++++--
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  25 +-
 .../iommu/{iommu-sva-lib.h => iommu-sva.h}    |   8 +-
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |  85 ++---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  28 +-
 drivers/iommu/intel/iommu.c                   |  20 +-
 drivers/iommu/intel/svm.c                     | 135 +++----
 drivers/iommu/io-pgfault.c                    |  71 +---
 drivers/iommu/iommu-sva-lib.c                 |  71 ----
 drivers/iommu/iommu-sva.c                     | 331 ++++++++++++++++++
 drivers/iommu/iommu.c                         | 239 +++++++------
 drivers/iommu/Makefile                        |   2 +-
 13 files changed, 706 insertions(+), 421 deletions(-)
 rename drivers/iommu/{iommu-sva-lib.h => iommu-sva.h} (88%)
 delete mode 100644 drivers/iommu/iommu-sva-lib.c
 create mode 100644 drivers/iommu/iommu-sva.c

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2.25.1