CVE-2021-47035

In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Remove WO permissions on second-level paging entries When the
first level page table is used for IOVA translation, it only supports
Read-Only and Read-Write permissions. The Write-Only permission is not
supported as the PRESENT bit (implying Read permission) should always set.
When using second level, we still give separate permissions that allows
WriteOnly which seems inconsistent and awkward. We want to have consistent
behavior. After moving to 1st level, we don’t want things to work
sometimes, and break if we use 2nd level for the same mappings. Hence
remove this configuration.