[XEN PATCH v3 0/3] x86/iommu: Drop IOMMU support when cx16 isn't supported

[Teddy Astie <teddy.astie@xxxxxxxxxx>]

All hardware that supports VT-d/AMD-Vi that exists also supports cx16 (aside
specifically crafted virtual machines).

Some IOMMU code paths in Xen consider cases where VT-d/AMD-Vi is supported
while cx16 isn't, those paths may be bugged and are barely tested, dead code
in practice.

Disable IOMMU in case we have IOMMU hardware but no cx16, then cleanup
no-cx16 handling logic from VT-d and AMD-Vi drivers.

Teddy

Changed in v2:

 * Added cleanup no-cx16 code for x2APIC
 * Fixed commit and code formatting
 * Added missing Suggested-by note

Changed in v3:

 * Use -ENODEV instead of -ENOSYS.

Teddy Astie (3):
  VT-d: Disable IOMMU if cx16 isn't supported
  AMD-Vi: Disable IOMMU if cx16 isn't supported
  VT-d: Cleanup MAP_SINGLE_DEVICE and related code

 xen/arch/x86/apic.c                         |  6 ++
 xen/drivers/passthrough/amd/iommu_map.c     | 42 ++++------
 xen/drivers/passthrough/amd/pci_amd_iommu.c |  6 ++
 xen/drivers/passthrough/vtd/intremap.c      | 65 ++++-----------
 xen/drivers/passthrough/vtd/iommu.c         | 92 +++++++--------------
 xen/drivers/passthrough/vtd/vtd.h           |  5 +-
 6 files changed, 71 insertions(+), 145 deletions(-)

-- 
2.44.0



Teddy Astie | Vates XCP-ng Intern

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