mbox series

[v7,00/24] iommu: Shared Virtual Addressing for SMMUv3

Message ID 20200519175502.2504091-1-jean-philippe@linaro.org
Headers show
Series iommu: Shared Virtual Addressing for SMMUv3 | expand

Message

Jean-Philippe Brucker May 19, 2020, 5:54 p.m. UTC 
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 v6 [1]:
* Rename ioasid_free() to ioasid_put() in patch 02, requiring changes to
  the Intel drivers.
* Use mmu_notifier_register() in patch 16 to avoid copying the ops and
  simplify the invalidate() notifier in patch 17.
* As a result, replace context spinlock with a mutex. Simplified locking in
  patch 11 (That patch still looks awful, but I think the series is more
  readable overall). And I've finally been able to remove the GFP_ATOMIC
  allocations.
* Use a single patch (04) for io-pgfault.c, since the code was simplified
  in v6. Fixed partial list in patch 04.

[1] https://lore.kernel.org/linux-iommu/20200430143424.2787566-1-jean-philippe@linaro.org/

Jean-Philippe Brucker (24):
  mm: Add a PASID field to mm_struct
  iommu/ioasid: Add ioasid references
  iommu/sva: Add PASID helpers
  iommu: Add a page fault handler
  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                         |   12 +
 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                   | 1552 +++++++++++++++--
 drivers/iommu/intel-iommu.c                   |    4 +-
 drivers/iommu/intel-svm.c                     |    6 +-
 drivers/iommu/io-pgfault.c                    |  459 +++++
 drivers/iommu/io-pgtable-arm.c                |   27 +-
 drivers/iommu/ioasid.c                        |   38 +-
 drivers/iommu/iommu-sva.c                     |   85 +
 drivers/iommu/of_iommu.c                      |    5 +-
 drivers/pci/ats.c                             |    4 +
 MAINTAINERS                                   |    3 +-
 23 files changed, 2286 insertions(+), 165 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

Comments

Will Deacon May 21, 2020, 10:35 a.m. UTC | #1 
Hi Jean-Philippe,

On Tue, May 19, 2020 at 07:54:38PM +0200, Jean-Philippe Brucker wrote:
> 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 v6 [1]:
> * Rename ioasid_free() to ioasid_put() in patch 02, requiring changes to
>   the Intel drivers.
> * Use mmu_notifier_register() in patch 16 to avoid copying the ops and
>   simplify the invalidate() notifier in patch 17.
> * As a result, replace context spinlock with a mutex. Simplified locking in
>   patch 11 (That patch still looks awful, but I think the series is more
>   readable overall). And I've finally been able to remove the GFP_ATOMIC
>   allocations.
> * Use a single patch (04) for io-pgfault.c, since the code was simplified
>   in v6. Fixed partial list in patch 04.

There's an awful lot here and it stretches across quite a few subsystems,
with different git trees. What's the plan for merging it?

I'm happy to take some of the arm64 and smmu changes for 5.8, then perhaps
we can review what's left and target 5.9? It would also be helpful to split
that up into separate series where there aren't strong dependencies, I
think.

Will
Will Deacon May 21, 2020, 2:17 p.m. UTC | #2 
On Thu, May 21, 2020 at 11:35:14AM +0100, Will Deacon wrote:
> On Tue, May 19, 2020 at 07:54:38PM +0200, Jean-Philippe Brucker wrote:
> > 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 v6 [1]:
> > * Rename ioasid_free() to ioasid_put() in patch 02, requiring changes to
> >   the Intel drivers.
> > * Use mmu_notifier_register() in patch 16 to avoid copying the ops and
> >   simplify the invalidate() notifier in patch 17.
> > * As a result, replace context spinlock with a mutex. Simplified locking in
> >   patch 11 (That patch still looks awful, but I think the series is more
> >   readable overall). And I've finally been able to remove the GFP_ATOMIC
> >   allocations.
> > * Use a single patch (04) for io-pgfault.c, since the code was simplified
> >   in v6. Fixed partial list in patch 04.
> 
> There's an awful lot here and it stretches across quite a few subsystems,
> with different git trees. What's the plan for merging it?
> 
> I'm happy to take some of the arm64 and smmu changes for 5.8, then perhaps
> we can review what's left and target 5.9? It would also be helpful to split
> that up into separate series where there aren't strong dependencies, I
> think.

Hmm, so the way the series is structured makes it quite difficult to apply
much of this at all :(

I've taken patch 5 into the arm64 tree and patch 8 into the smmu tree. I'll
leave a couple of Acks on some of the simpler patches, but I think this
really needs splitting up a bit to make it more manageable.

I also notice a bunch of TODOs that get introduced and then removed. Given
that the series needs to be bisectable, these shouldn't be needed and can
just be removed.

Thanks,

Will