[PATCH v6 00/25] iommu: Shared Virtual Addressing for SMMUv3

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

Shared Virtual Addressing (SVA) allows to share process page tables with
devices using the IOMMU, PASIDs and I/O page faults. Add SVA support to
the Arm SMMUv3 driver.

Since v5 [1]:

* Added patches 1-3. Patch 1 adds a PASID field to mm_struct as
  discussed in [1] and [2]. This is also needed for Intel ENQCMD. Patch
  2 adds refcounts to IOASID and patch 3 adds a couple of helpers to
  allocate the PASID.

* Dropped most of iommu-sva.c. After getting rid of io_mm following
  review of v5, there wasn't enough generic code left to justify the
  indirect branch overhead of io_mm_ops in the MMU notifiers. I ended up
  with more glue than useful code, and couldn't find an easy way to deal
  with domains in the SMMU driver (we keep PASID tables per domain,
  while x86 keeps them per device). The direct approach in patch 17 is
  nicer and a little easier to read. The SMMU driver only gained 160
  lines, while iommu-sva lost 470 lines.

  As a result I dropped the MMU notifier patch.

  Jacob, one upside of this rework is that we now free ioasids in
  blocking context, which might help with your addition of notifiers to
  ioasid.c

* Simplified io-pgfault a bit, since flush() isn't called from mm exit
  path anymore.

* Fixed a bug in patch 17 (don't clear the stall bit when stall is
  forced).

You can find the latest version on https://jpbrucker.net/git/linux
branch sva/current, and sva/zip-devel for the Hisilicon zip accelerator.

[1] https://lore.kernel.org/linux-iommu/20200414170252.714402-1-jean-philippe@linaro.org/
[2] https://lore.kernel.org/linux-iommu/1585596788-193989-6-git-send-email-fenghua.yu@intel.com/

Jean-Philippe Brucker (25):
  mm: Add a PASID field to mm_struct
  iommu/ioasid: Add ioasid references
  iommu/sva: Add PASID helpers
  iommu: Add a page fault handler
  iommu/iopf: Handle mm faults
  arm64: mm: Add asid_gen_match() helper
  arm64: mm: Pin down ASIDs for sharing mm with devices
  iommu/io-pgtable-arm: Move some definitions to a header
  iommu/arm-smmu-v3: Manage ASIDs with xarray
  arm64: cpufeature: Export symbol read_sanitised_ftr_reg()
  iommu/arm-smmu-v3: Share process page tables
  iommu/arm-smmu-v3: Seize private ASID
  iommu/arm-smmu-v3: Add support for VHE
  iommu/arm-smmu-v3: Enable broadcast TLB maintenance
  iommu/arm-smmu-v3: Add SVA feature checking
  iommu/arm-smmu-v3: Add SVA device feature
  iommu/arm-smmu-v3: Implement iommu_sva_bind/unbind()
  iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops
  iommu/arm-smmu-v3: Add support for Hardware Translation Table Update
  iommu/arm-smmu-v3: Maintain a SID->device structure
  dt-bindings: document stall property for IOMMU masters
  iommu/arm-smmu-v3: Add stall support for platform devices
  PCI/ATS: Add PRI stubs
  PCI/ATS: Export PRI functions
  iommu/arm-smmu-v3: Add support for PRI

 drivers/iommu/Kconfig                         |   11 +
 drivers/iommu/Makefile                        |    2 +
 .../devicetree/bindings/iommu/iommu.txt       |   18 +
 arch/arm64/include/asm/mmu.h                  |    1 +
 arch/arm64/include/asm/mmu_context.h          |   11 +-
 drivers/iommu/io-pgtable-arm.h                |   30 +
 drivers/iommu/iommu-sva.h                     |   15 +
 include/linux/ioasid.h                        |   10 +-
 include/linux/iommu.h                         |   53 +
 include/linux/mm_types.h                      |    4 +
 include/linux/pci-ats.h                       |    8 +
 arch/arm64/kernel/cpufeature.c                |    1 +
 arch/arm64/mm/context.c                       |  103 +-
 drivers/iommu/arm-smmu-v3.c                   | 1554 +++++++++++++++--
 drivers/iommu/io-pgfault.c                    |  458 +++++
 drivers/iommu/io-pgtable-arm.c                |   27 +-
 drivers/iommu/ioasid.c                        |   30 +-
 drivers/iommu/iommu-sva.c                     |   85 +
 drivers/iommu/of_iommu.c                      |    5 +-
 drivers/pci/ats.c                             |    4 +
 MAINTAINERS                                   |    3 +-
 21 files changed, 2275 insertions(+), 158 deletions(-)
 create mode 100644 drivers/iommu/io-pgtable-arm.h
 create mode 100644 drivers/iommu/iommu-sva.h
 create mode 100644 drivers/iommu/io-pgfault.c
 create mode 100644 drivers/iommu/iommu-sva.c

-- 
2.26.2

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