[PATCH v4 0/2] iommu/amd: Support for HATdis and HATS features

[Ankit Soni <Ankit.Soni@amd.com>]

This series comprises two features:

HATDis: When host address translation is not supported by the IOMMU,
the IVHD->attr[HATDis] bit is set. For instance, QEMU emulated vIOMMU
does not support dma tranlation for VFIO passthrough device.
Support has been added to check this bit and switch to guest page table 
mode, if supported. This feature is useful for cases where only interrupt
remapping is required.

EFR[HATS]: These bits indicate the maximum level supported for host page table
by the IOMMU. Modifications have been made to adjust the maximum host page table
level, starting with level 4. If these bits are set to 11b, the driver will
attempt to use the guest page table.

If guest page table mode is not supported, the driver will fail to probe
devices for DMA translations.
The interrupt remapping will continue to be supported.

---
v4:
- Relocate sysfs PD_MODE_NONE check case after iommu_device_register()
  along with return check.
v3:
- Add check before populating sysfs entries for iommu groups.
v2:
- Addressed comments from Vasant:
	- Added/Modified comments and logs.
	- Removed v1 page table assignment hunk.

Ankit Soni (2):
  iommu/amd: Add HATDis feature support
  iommu/amd: Add efr[HATS] max v1 page table level

 drivers/iommu/amd/amd_iommu.h       |  2 ++
 drivers/iommu/amd/amd_iommu_types.h |  7 ++++-
 drivers/iommu/amd/init.c            | 47 +++++++++++++++++++++++++++--
 drivers/iommu/amd/io_pgtable.c      |  4 +--
 drivers/iommu/amd/iommu.c           | 15 ++++++++-
 5 files changed, 69 insertions(+), 6 deletions(-)

-- 
2.43.0