[PATCH v3 00/11] iommu: Prepare to deliver page faults to user space

Lu Baolu
2023-08-17T23:44:26Z

When a user-managed page table is attached to an IOMMU, it is necessary
to deliver IO page faults to user space so that they can be handled
appropriately. One use case for this is nested translation, which is
currently being discussed in the mailing list.

I have posted a RFC series [1] that describes the implementation of
delivering page faults to user space through IOMMUFD. This series has
received several comments on the IOMMU refactoring, which I am trying to
address in this series.

The major refactoring includes:

- [PATCH 01 ~ 04] Move include/uapi/linux/iommu.h to
include/linux/iommu.h. Remove the unrecoverable fault data definition.
- [PATCH 05 ~ 06] Remove iommu_[un]register_device_fault_handler().
- [PATCH 07 ~ 11] Separate SVA and IOPF. Make IOPF a generic page fault
handling framework.

This is also available at github [2]. I would appreciate your feedback
on this series.

[1] https://lore.kernel.org/linux-iommu/20230530053724.232765-1-baolu.lu@linux.intel.com/
[2] https://github.com/LuBaolu/intel-iommu/commits/preparatory-io-pgfault-delivery-v3

Change log:
v3:
- Convert the fault data structures from uAPI to kAPI.
- Merge iopf_device_param into iommu_fault_param.
- Add debugging on domain lifetime for iopf.
- Remove patch "iommu: Change the return value of dev_iommu_get()".
- Remove patch "iommu: Add helper to set iopf handler for domain".
- Misc code refactoring and refining.

v2: https://lore.kernel.org/linux-iommu/20230727054837.147050-1-baolu.lu@linux.intel.com/
- Remove unrecoverable fault data definition as suggested by Kevin.
- Drop the per-device fault cookie code considering that doesn't make
much sense for SVA.
- Make the IOMMU page fault handling framework generic. So that it can
avaible for use cases other than SVA.

v1: https://lore.kernel.org/linux-iommu/20230711010642.19707-1-baolu.lu@linux.intel.com/

Lu Baolu (11):
iommu: Move iommu fault data to linux/iommu.h
iommu/arm-smmu-v3: Remove unrecoverable faults reporting
iommu: Remove unrecoverable fault data
iommu: Cleanup iopf data structure definitions
iommu: Merge iopf_device_param into iommu_fault_param
iommu: Remove iommu_[un]register_device_fault_handler()
iommu: Prepare for separating SVA and IOPF
iommu: Move iopf_handler() to iommu-sva.c
iommu: Make iommu_queue_iopf() more generic
iommu: Add debugging on domain lifetime for iopf
iommu: Separate SVA and IOPF in Makefile and Kconfig

include/linux/iommu.h | 202 ++++++++++++++---
drivers/iommu/iommu-sva.h | 71 ------
include/uapi/linux/iommu.h | 161 --------------
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 14 +-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 47 ++--
drivers/iommu/intel/iommu.c | 25 +--
drivers/iommu/intel/svm.c | 1 -
drivers/iommu/io-pgfault.c | 208 ++++++++----------
drivers/iommu/iommu-sva.c | 49 ++++-
drivers/iommu/iommu.c | 132 +++--------
MAINTAINERS | 1 -
drivers/iommu/Kconfig | 4 +
drivers/iommu/Makefile | 3 +-
drivers/iommu/intel/Kconfig | 1 +
14 files changed, 362 insertions(+), 557 deletions(-)
delete mode 100644 drivers/iommu/iommu-sva.h
delete mode 100644 include/uapi/linux/iommu.h

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2.34.1