[PATCH v4 00/26] iommu: Shared Virtual Addressing and SMMUv3 support

Jean-Philippe Brucker
2020-02-24T18:24:32Z

Shared Virtual Addressing (SVA) allows to share process page tables with
devices using the IOMMU. Add a generic implementation of the IOMMU SVA
API, and add support in the Arm SMMUv3 driver.

Previous versions of this patchset were sent over a year ago [1][2] but
we've made a lot of progress since then:

* ATS support for SMMUv3 was merged in v5.2.
* The bind() and fault reporting APIs have been merged in v5.3.
* IOASID were added in v5.5.
* SMMUv3 PASID was added in v5.6, with some pending for v5.7.

* The first user of the bind() API will be merged in v5.7 [3]. The zip
accelerator is also the first piece of hardware that I've been able to
use for testing (previous versions were developed with software models)
and I now have tools for evaluating SVA performance. Unfortunately I
still don't have hardware that supports ATS and PRI; the zip accelerator
uses stall.

These are the remaining changes for SVA support in SMMUv3. Since v3 [1]
I fixed countless bugs and - I think - addressed everyone's comments.
Thanks to recent MMU notifier rework, iommu-sva.c is a lot more
straightforward. I'm still unhappy with the complicated locking in the
SMMUv3 driver resulting from patch 12 (Seize private ASID), but I
haven't found anything better.

Please find all SVA patches on branches sva/current and sva/zip-devel at
https://jpbrucker.net/git/linux

[1] https://lore.kernel.org/linux-iommu/20180920170046.20154-1-jean-philippe.brucker@arm.com/
[2] https://lore.kernel.org/linux-iommu/20180511190641.23008-1-jean-philippe.brucker@arm.com/
[3] https://lore.kernel.org/linux-iommu/1581407665-13504-1-git-send-email-zhangfei.gao@linaro.org/

Jean-Philippe Brucker (26):
mm/mmu_notifiers: pass private data down to alloc_notifier()
iommu/sva: Manage process address spaces
iommu: Add a page fault handler
iommu/sva: Search mm by PASID
iommu/iopf: Handle mm faults
iommu/sva: Register page fault handler
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 dev_to_master() helper
iommu/arm-smmu-v3: Implement mm operations
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
iommu/arm-smmu-v3: Ratelimit event dump
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 symbols of PRI functions
iommu/arm-smmu-v3: Add support for PRI

.../devicetree/bindings/iommu/iommu.txt | 18 +
arch/arm64/include/asm/mmu.h | 1 +
arch/arm64/include/asm/mmu_context.h | 11 +-
arch/arm64/kernel/cpufeature.c | 1 +
arch/arm64/mm/context.c | 103 +-
drivers/iommu/Kconfig | 13 +
drivers/iommu/Makefile | 2 +
drivers/iommu/arm-smmu-v3.c | 1354 +++++++++++++++--
drivers/iommu/io-pgfault.c | 533 +++++++
drivers/iommu/io-pgtable-arm.c | 27 +-
drivers/iommu/io-pgtable-arm.h | 30 +
drivers/iommu/iommu-sva.c | 596 ++++++++
drivers/iommu/iommu-sva.h | 64 +
drivers/iommu/iommu.c | 1 +
drivers/iommu/of_iommu.c | 5 +-
drivers/misc/sgi-gru/grutlbpurge.c | 4 +-
drivers/pci/ats.c | 4 +
include/linux/iommu.h | 73 +
include/linux/mmu_notifier.h | 10 +-
include/linux/pci-ats.h | 8 +
mm/mmu_notifier.c | 6 +-
21 files changed, 2699 insertions(+), 165 deletions(-)
create mode 100644 drivers/iommu/io-pgfault.c
create mode 100644 drivers/iommu/io-pgtable-arm.h
create mode 100644 drivers/iommu/iommu-sva.c
create mode 100644 drivers/iommu/iommu-sva.h

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2.25.0