[v14,00/10] iommu: I/O page faults for SMMUv3

Message

Jean-Philippe Brucker April 1, 2021, 3:47 p.m. UTC

Add stall support to the SMMUv3 driver, along with a common I/O Page
Fault handler.

Since [v13] I added review and ack tags (Thanks!), and a lockdep_assert.
It would be good to have all of it in v5.13, since patch 10 introduces
the first user for the IOPF interface from patch 6.  But if that's not
possible, please pick patches 1-6 so the Vt-d driver can start using
them.

[v13] https://lore.kernel.org/linux-iommu/[e-mail]/

Jean-Philippe Brucker (10):
  iommu: Fix comment for struct iommu_fwspec
  iommu/arm-smmu-v3: Use device properties for pasid-num-bits
  iommu: Separate IOMMU_DEV_FEAT_IOPF from IOMMU_DEV_FEAT_SVA
  iommu/vt-d: Support IOMMU_DEV_FEAT_IOPF
  uacce: Enable IOMMU_DEV_FEAT_IOPF
  iommu: Add a page fault handler
  iommu/arm-smmu-v3: Maintain a SID->device structure
  dt-bindings: document stall property for IOMMU masters
  ACPI/IORT: Enable stall support for platform devices
  iommu/arm-smmu-v3: Add stall support for platform devices

 drivers/iommu/Makefile                        |   1 +
 .../devicetree/bindings/iommu/iommu.txt       |  18 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  56 ++-
 drivers/iommu/iommu-sva-lib.h                 |  53 ++
 include/linux/iommu.h                         |  26 +-
 drivers/acpi/arm64/iort.c                     |  15 +-
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |  59 ++-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 355 ++++++++++++--
 drivers/iommu/intel/iommu.c                   |  11 +-
 drivers/iommu/io-pgfault.c                    | 461 ++++++++++++++++++
 drivers/iommu/of_iommu.c                      |   5 -
 drivers/misc/uacce/uacce.c                    |  39 +-
 12 files changed, 1025 insertions(+), 74 deletions(-)
 create mode 100644 drivers/iommu/io-pgfault.c

Comments

Jean-Philippe Brucker April 6, 2021, 8:01 a.m. UTC | #1

On Thu, Apr 01, 2021 at 06:15:02PM +0100, Will Deacon wrote:
> On Thu, Apr 01, 2021 at 05:47:09PM +0200, Jean-Philippe Brucker wrote:
> > Add stall support to the SMMUv3 driver, along with a common I/O Page
> > Fault handler.
> > 
> > Since [v13] I added review and ack tags (Thanks!), and a lockdep_assert.
> > It would be good to have all of it in v5.13, since patch 10 introduces
> > the first user for the IOPF interface from patch 6.  But if that's not
> > possible, please pick patches 1-6 so the Vt-d driver can start using
> > them.
> 
> Patches 1-7 look good to me, but I'm not convinced about the utility of
> stalling faults so I'd prefer the later patches to come along with a
> real user.

As others said, it is possible to assign queues from the compression and
crypto accelerators on the Kunpeng920 to userspace, using the uacce char
device (upstream since last year, but waiting for implementations of the
SVA API in IOMMU drivers). I've been using that platform for testing my
code for the past year, with the UADK tool as well as an openssl plugin.

Securely assignig a queue to userspace requires full SVA support in
SMMUv3, which consists of PASID, page table sharing, and I/O page faults.
The first two were already merged, and the third one requires either Stall
or PRI. I'm not submitting PRI support at the moment because there is no
hardware, but the Hisilicon platform implements stall and will be able to
use it right away.

Thanks,
Jean

Joerg Roedel April 7, 2021, 8:55 a.m. UTC | #2

On Thu, Apr 01, 2021 at 05:47:09PM +0200, Jean-Philippe Brucker wrote:
> Jean-Philippe Brucker (10):
>   iommu: Fix comment for struct iommu_fwspec
>   iommu/arm-smmu-v3: Use device properties for pasid-num-bits
>   iommu: Separate IOMMU_DEV_FEAT_IOPF from IOMMU_DEV_FEAT_SVA
>   iommu/vt-d: Support IOMMU_DEV_FEAT_IOPF
>   uacce: Enable IOMMU_DEV_FEAT_IOPF
>   iommu: Add a page fault handler
>   iommu/arm-smmu-v3: Maintain a SID->device structure

Applied the first 7 patches, thanks.