Linux 5.17 EDAC Driver Brings Support For New AMD Zen CPUs, RDDR5 / LRDDR5 Memory

With the Linux 5.17 kernel merge window formally open today, among the early pull requests sent out this morning were the Error Detection And Correction (EDAC) driver updates which is notable this time in preparation for next-generation AMD EPYC server hardware.

The most exciting EDAC work for this next kernel cycle is preparation for next-generation AMD Zen processors as well as adding support for DDR5 system memory to this kernel code that deals with ECC and other error detection/correction handling. The DDR5 support within the scope of EDAC is both for Registered DDR5 and Load-Reduced DDR5 memory. This EDAC work I previously reported on last month while the news today is that it's been submitted for debuting in Linux 5.17.

The new AMD Zen processor support in this context comes down to the AMD Family 19h Models 10h-1Fh and A0h-AFh. Those new CPU models I spotted back in November when the CPU temperature driver support was being added. Given that it's going along with RDDR5/LRDDR5 memory support being added, it seems pretty safe to assume that they are for Zen 4 / Zen 4C.

That's the exciting work this cycle in the EDAC subsystem. The only other non-AMD noteworthy change there is support for the Synopsys v3 DDR controller in its driver. The list of EDAC changes for Linux 5.17 can be found via this pull request.

While not related to EDAC but on the AMD front: also sent out this morning were the latest SEV updates for Linux 5.17. There are a few AMD Secure Encrypted Virtualization updates -- namely the work around code sharing between AMD SEV and Intel TDX -- but sadly still no SEV-SNP support has been mainlined yet for the new functionality with EPYC 7003 processors. There does remain the SEV-SNP out-of-tree patches available.