To properly support instance types in AWS with > 255 cores we need to make sure that commit c40aaaac1018ff1382f2d35df5129a6bcea3df6b ("iommu/vt-d: Gracefully handle DMAR units with no supported address widths") is applied across all our linux-aws kernels.
[Impact]
To properly support instance types in AWS with > 255 cores we need to make sure that commit c40aaaac1018ff1 382f2d35df5129a 6bcea3df6b ("iommu/vt-d: Gracefully handle DMAR units with no supported address widths") is applied across all our linux-aws kernels.
[Test Case]
Tests performed by AWS.
[Fix]
Apply/backport commit c40aaaac1018ff1 382f2d35df5129a 6bcea3df6b.
[Regression potential]
The fix is affecting only intel IOMMU and it is an upstream fix, so the regression potential is minimal.