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

[Jacob Pan]

Hi,

Any comments on this? I know we have some opens w.r.t. PASID management
UAPI, but I think having this common kernel API features should be
justified.

Thanks!

Jacob


On Mon, 28 Sep 2020 14:38:27 -0700, Jacob Pan <jacob.pan.linux@xxxxxxxxx>
wrote:

> 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@xxxxxxxxx>
> Wu Hao <hao.wu@xxxxxxxxx>
> Ashok Raj <ashok.raj@xxxxxxxxx>
> Kevin Tian <kevin.tian@xxxxxxxxx>
> 
> 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
> 


Thanks,

Jacob