[PATCH v3 00/14] IOASID extensions for guest SVA

Jacob Pan
2020-09-28T21:36:48Z

IOASID was introduced in v5.5 as a generic kernel allocator service for
both PCIe Process Address Space ID (PASID) and ARM SMMU's Sub Stream
ID. In addition to basic ID allocation, ioasid_set was defined as a
token that is shared by a group of IOASIDs. This set token can be used
for permission checking, but lack of some features to address the
following needs by guest Shared Virtual Address (SVA).
- Manage IOASIDs by group, group ownership, quota, etc.
- State synchronization among IOASID users
- Non-identity guest-host IOASID mapping
- Lifecycle management across many users

This patchset introduces the following extensions as solutions to the
problems above.
- Redefine and extend IOASID set such that IOASIDs can be managed by groups.
- Add notifications for IOASID state synchronization
- Add reference counting for life cycle alignment among users
- Support ioasid_set private IDs, which can be used as guest IOASIDs
Please refer to Documentation/ioasid.rst in enclosed patch 1/9 for more
details.

This patchset only included VT-d driver as users of some of the new APIs.
VFIO and KVM patches are coming up to fully utilize the APIs introduced
here.

You can find this series at:
https://github.com/jacobpan/linux.git ioasid_v3
(VFIO and KVM patches will be available at this branch when published.)

This work is a result of collaboration with many people:
Liu, Yi L <yi.l.liu@intel.com>
Wu Hao <hao.wu@intel.com>
Ashok Raj <ashok.raj@intel.com>
Kevin Tian <kevin.tian@intel.com>

Thanks,

Jacob

Changelog:

V3:
- Use consistent ioasid_set_ prefix for ioasid_set level APIs
- Make SPID and private detach/attach APIs symmetric
- Use the same ioasid_put semantics as Jean-Phillippe IOASID reference patch
- Take away the public ioasid_notify() function, notifications are now emitted
by IOASID core as a result of certain IOASID APIs
- Partition into finer incremental patches
- Miscellaneous cleanup, locking, exception handling fixes based on v2 reviews

V2:
- Redesigned ioasid_set APIs, removed set ID
- Added set private ID (SPID) for guest PASID usage.
- Add per ioasid_set notification and priority support.
- Back to use spinlocks and atomic notifications.
- Added async work in VT-d driver to perform teardown outside atomic context

Jacob Pan (14):
docs: Document IO Address Space ID (IOASID) APIs
iommu/ioasid: Rename ioasid_set_data()
iommu/ioasid: Add a separate function for detach data
iommu/ioasid: Support setting system-wide capacity
iommu/ioasid: Redefine IOASID set and allocation APIs
iommu/ioasid: Introduce API to adjust the quota of an ioasid_set
iommu/ioasid: Add an iterator API for ioasid_set
iommu/ioasid: Add reference couting functions
iommu/ioasid: Introduce ioasid_set private ID
iommu/ioasid: Introduce notification APIs
iommu/ioasid: Support mm type ioasid_set notifications
iommu/vt-d: Remove mm reference for guest SVA
iommu/vt-d: Listen to IOASID notifications
iommu/vt-d: Store guest PASID during bind

Documentation/driver-api/ioasid.rst | 648 ++++++++++++++++++++++++++
drivers/iommu/intel/iommu.c | 29 +-
drivers/iommu/intel/pasid.h | 1 +
drivers/iommu/intel/svm.c | 132 +++++-
drivers/iommu/ioasid.c | 890 ++++++++++++++++++++++++++++++++++--
include/linux/intel-iommu.h | 2 +
include/linux/ioasid.h | 197 +++++++-
7 files changed, 1830 insertions(+), 69 deletions(-)
create mode 100644 Documentation/driver-api/ioasid.rst