AMD Closing In On IOMMU SVA Support For Linux

The IOMMU changes for Linux 6.7 aren't particularly noteworthy besides adding SMMUv2 support for the Qualcomm SDM670 and SM7150 SoCs. But the IOMMU updates also take the kernel one step away from supporting Shared Virtual Addressing (SVA) on AMD platforms in the near future.

IOMMU Shared Virtual Addressing allows for sharing process address spaces with devices. SVA is akin to OpenCL's Shared Virtual Machine (SVM). This IOMMU SVA support with process address space sharing can lead to less complexity in application and device driver code. Arm engineers worked on the IOMMU SVA infrastructure for the Linux kernel years ago and finally the AMD IOMMU driver support for it is getting into shape.

Merged for Linux 6.7 is the third of four patch series for enabling AMD SVA IOMMU support. The IOMMU pull for Linux 6.7 lands those SVA support patches but not across the finish line yet.

The remaining 12 patches for making up "part 4" are currently under review. Once those patches land AMD SVA support will be ready and support shared virtual addressing with devices supporting PCI ATS, PASID, and PRI capabilities.

Hopefully we see this AMD SVA feature code wrapped up in time for Linux 6.8 in early 2024.