[RFC 0/8] iommufd support pasid attach/replace

Yi Liu
2023-09-26T09:27:03Z

PASID (Process Address Space ID) is a PCIe extension to tag the DMA
transactions out of a physical device, and most modern IOMMU hardware
have supported PASID granular address translation. So a PASID-capable
devices can be attached to multiple hwpts (a.k.a. domains), each attachment
is tagged with a PASID.

This series first adds a missing iommu API to replace domain for a pasid,
then adds iommufd APIs for device drivers to attach/replace/detach pasid
to/from hwpt per userspace's request, and adds selftest to validate the
iommufd APIs.

pasid attach/replace is mandatory on Intel VT-d given the PASID table
locates in the physical address space hence must be managed by the kernel,
both for supporting vSVA and coming SIOV. But it's optional on ARM/AMD
which allow configuring the PASID/CD table either in host physical address space
or nested on top of an GPA address space. This series only add VT-d support
as the minimal requirement.

Complete code can be found in below link:

https://github.com/yiliu1765/iommufd/tree/iommufd_pasid

Regards,
Yi Liu

Kevin Tian (1):
iommufd: Support attach/replace hwpt per pasid

Lu Baolu (2):
iommu: Introduce a replace API for device pasid
iommu/vt-d: Add set_dev_pasid callback for nested domain

Yi Liu (5):
iommufd: replace attach_fn with a structure
iommufd/selftest: Add set_dev_pasid and remove_dev_pasid in mock iommu
iommufd/selftest: Add a helper to get test device
iommufd/selftest: Add test ops to test pasid attach/detach
iommufd/selftest: Add coverage for iommufd pasid attach/detach

drivers/iommu/intel/nested.c | 47 +++++
drivers/iommu/iommu-priv.h | 2 +
drivers/iommu/iommu.c | 73 ++++++--
drivers/iommu/iommufd/Makefile | 1 +
drivers/iommu/iommufd/device.c | 42 +++--
drivers/iommu/iommufd/iommufd_private.h | 16 ++
drivers/iommu/iommufd/iommufd_test.h | 24 +++
drivers/iommu/iommufd/pasid.c | 152 ++++++++++++++++
drivers/iommu/iommufd/selftest.c | 158 ++++++++++++++--
include/linux/iommufd.h | 6 +
tools/testing/selftests/iommu/iommufd.c | 172 ++++++++++++++++++
.../selftests/iommu/iommufd_fail_nth.c | 28 ++-
tools/testing/selftests/iommu/iommufd_utils.h | 78 ++++++++
13 files changed, 756 insertions(+), 43 deletions(-)
create mode 100644 drivers/iommu/iommufd/pasid.c

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2.34.1