Linux 4.14 To Get 5-Level Paging, AMD Secure Memory Encryption

Ingo Molnar has sent in his many pull requests of new feature work targeting the Linux 4.14 merge window.

One of Ingo's pull requests of interest to us are the memory management updates, which include some interesting feature work. First up, 5-level paging is now in place for upcoming Intel CPUs. Five-level paging allows the CPUs to support up to 128PB of virtual address space and 4PB of physical RAM. It's an interesting improvement from Intel and actually needed for the modern demands of x86 super computers beginning to hit the existing memory limitations.

There is also now PCID optimized TLB flushing for newer Intel CPUs. This can allow for skipping TLB flushing in many instances.

On the AMD side there is also now the Secure Memory Encryption (SME) support for use with AMD EPYC processors. AMD SME allows system RAM to be transparently encrypted and decrypted by the CPU. With EPYC CPUs now shipping, great to see that code landed.

More details via this pull request.