[PATCH 0/7] iommu/amd: Enforce IOMMU restrictions for SNP-enabled system

[Suravee Suthikulpanit via iommu <iommu@lists.linux-foundation.org>]

SNP-enabled system requires IOMMU v1 page table to be configured with
non-zero DTE[Mode] for DMA-capable devices. This effects a number of
usecases such as IOMMU pass-through mode and AMD IOMMUv2 APIs for
binding/unbinding pasid.

The series introduce a global variable to check SNP-enabled state
during driver initialization, and use it to enforce the SNP restrictions
during runtime.

Also, for non-DMA-capable devices such as IOAPIC, the recommendation
is to set DTE[TV] and DTE[Mode] to zero on SNP-enabled system.
Therefore, additinal checks is added before setting DTE[TV].

Testing:
  - Tested booting and verify dmesg.
  - Tested booting with iommu=pt
  - Tested loading amd_iommu_v2 driver
  - Tested changing the iommu domain at runtime
  - Tested booting SEV/SNP-enabled guest

Pre-requisite:
  - [PATCH v3 00/35] iommu/amd: Add multiple PCI segments support
    https://lore.kernel.org/linux-iommu/20220511072141.15485-29-vasant.hegde@amd.com/T/

Note:
  - Previously discussed on here:
    [PATCH v2] iommu/amd: Set translation valid bit only when IO page tables are in used
    https://www.spinics.net/lists/kernel/msg4351005.html

Best Regards,
Suravee

Brijesh Singh (1):
  iommu/amd: Introduce function to check SEV-SNP support

Suravee Suthikulpanit (6):
  iommu/amd: Process all IVHDs before enabling IOMMU features
  iommu/amd: Introduce a global variable for tracking SNP enable status
  iommu/amd: Set translation valid bit only when IO page tables are in
    use
  iommu: Add domain_type_supported() callback in iommu_ops
  iommu/amd: Do not support IOMMU_DOMAIN_IDENTITY when SNP is enabled
  iommu/amd: Do not support IOMMUv2 APIs when SNP is enabled

 drivers/iommu/amd/amd_iommu_types.h |  11 +++
 drivers/iommu/amd/init.c            | 111 +++++++++++++++++++++++-----
 drivers/iommu/amd/iommu.c           |  31 +++++++-
 drivers/iommu/iommu.c               |  13 +++-
 include/linux/iommu.h               |  11 +++
 5 files changed, 153 insertions(+), 24 deletions(-)

-- 
2.32.0

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu