[PATCH v5 00/12] iommu: SVA and IOPF refactoring

From: Lu Baolu
Date: Sun May 01 2022 - 21:52:09 EST


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 has been functionally tested on an x86 machine and compile
tested for other architectures.

This series is also available on github:
[2] https://github.com/LuBaolu/intel-iommu/commits/iommu-sva-refactoring-v5

Please review and suggest.

Best regards,
baolu

Change log:
v5:
- Address review comments from Jean-Philippe Brucker. Very appreciated!
- Remove redundant pci aliases check in
device_group_immutable_singleton().
- Treat all buses exept PCI as static in immutable singleton check.
- As the sva_bind/unbind() have already guaranteed sva domain free only
after iopf_queue_flush_dev(), remove the unnecessary domain refcount.
- Move domain get() out of the list iteration in iopf_handle_group().

v4:
- https://lore.kernel.org/linux-iommu/20220421052121.3464100-1-baolu.lu@xxxxxxxxxxxxxxx/
- Solve the overlap with another series and make this series
self-contained.
- No objection to the abstraction of data structure during v3 review.
Hence remove the RFC subject prefix.
- Refine the immutable singleton group code according to Kevin's
comments.

v3:
- https://lore.kernel.org/linux-iommu/20220410102443.294128-1-baolu.lu@xxxxxxxxxxxxxxx/
- 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.

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.

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

Dave Jiang (1):
dmaengine: idxd: Separate user and kernel pasid enabling

Lu Baolu (11):
iommu: Add pasid_bits field in struct dev_iommu
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 | 100 ++++--
drivers/dma/idxd/idxd.h | 6 +
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 25 +-
.../iommu/{iommu-sva-lib.h => iommu-sva.h} | 3 +-
drivers/dma/idxd/cdev.c | 4 +-
drivers/dma/idxd/init.c | 30 +-
.../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 | 66 +---
drivers/iommu/iommu-sva-lib.c | 71 ----
drivers/iommu/iommu-sva.c | 328 ++++++++++++++++++
drivers/iommu/iommu.c | 189 +++++-----
drivers/iommu/Makefile | 2 +-
16 files changed, 672 insertions(+), 425 deletions(-)
rename drivers/iommu/{iommu-sva-lib.h => iommu-sva.h} (91%)
delete mode 100644 drivers/iommu/iommu-sva-lib.c
create mode 100644 drivers/iommu/iommu-sva.c

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2.25.1