Linux 5.6 Continues Work On Intel VT-d Nested Mode Support

The IOMMU changes have been sent in for the ongoing Linux 5.6 kernel merge window.

On the Intel front with the IOMMU driver changes are prep patches for Intel VT-d nested mode support. The changes also allow for toggling VT-d Scalable Mode via a new Kconfig switch INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON though this is just in regards to the default kernel behavior and can Scalable Mode with VT-d 3.0 can still be forced on at run-time with the intel_iommu=sm_on kernel option.

Besides the IOMMU VT-d work on nested mode support, there are also AMD IOMMU changes. The AMD changes for this kernel version amount to code clean-ups and refining their x2APIC detection.

There are also numerous ARM changes this time around, all of which are laid out via this pull request.