The AMD Zen-Based Hygon Dhyana CPU Support Landing In The Mainline Linux Kernel

Hygon's Dhyana SoC, the facsimile of the AMD Zen microarchitecture as a result of the AMD-Chinese joint venture to begin spinning up domestic x86 chips for the Chinese data center market, will be supported by the next version of the Linux kernel.

Going back a number of months I have been writing about the Linux kernel patches for Hygon Dhyana that effectively amount to copying the AMD Zen code-paths within the Linux kernel to use them as well for this x86 Chinese server SoC based on EPYC. After several rounds of patch revisions, that code is into shape and is now making its maiden voyage to the Linux kernel.

The Dhyana x86 CPU support was sent in today as part of the x86/cpu changes for the just-opened Linux 4.20~5.0 kernel merge window. It's just a few hundred lines of code of introducing the new Hygon/Dhyana identifiers and then adding them to the Zen code-paths ranging from the power management code to PCI to KVM/Xen and other areas of the Linux kernel having Zen-specific code/support. There are no other changes, showing just how close the Dhyana is to existing AMD Zen1 processors.

So with Linux 4.20~5.0 the kernel should be working on these Chinese servers or will be found out-of-the-box by the time of Ubuntu 19.04, Fedora 30 (or F29 updates), etc.