The in-development [1]Linux 6.13 kernel is bringing a lot of exciting improvements for AMD Linux customers.

In addition to [2]AMD P-State being the default now for 5th Gen EPYC CPUs rather than the generic ACPI CPUFreq driver to provide greater power efficiency, there is a lot more in tow. There is also the introduction of the [3]AMD 3D V-Cache Optimizer driver and other changes. Merged yesterday providing several new AMD features was [4]the x86/cpu pull request that is predominantly AMD processor changes. The x86/cpu highlights for the Linux 6.13 merge window include:

- Add a feature flag which denotes AMD CPUs supporting workload classification with the purpose of using such hints when making scheduling decisions

- Determine the boost enumerator for each AMD core based on its type: efficiency or performance, in the cppc driver

- Add the type of a CPU to the topology CPU descriptor with the goal of supporting and making decisions based on the type of the respective core

- Add a feature flag to denote AMD cores which have heterogeneous topology and enable SD_ASYM_PACKING for those

- Check microcode revisions before disabling PCID on Intel

- Cleanups and fixlets

A lot continues to be going on around better supporting AMD heterogeneous processors under Linux with a mix of performance "classic" and efficiency "dense" cores. There's the [5]AMD heterogeneous topology patches in this pull, [6]workload classification bits, and other bits.

Separately was also the [7]x86/sev pull request of AMD Secure Encrypted Virtualization (SEV) updates for Linux 6.13:

- Do the proper memory conversion of guest memory in order to be able to kexec kernels in SNP guests along with other adjustments and cleanups to that effect

- Start converting and moving functionality from the sev-guest driver intocore code with the purpose of supporting the secure TSC SNP feature where the hypervisor cannot influence the TSC exposed to the guest anymore

- Add a "nosnp" cmdline option in order to be able to disable SNP support in the hypervisor and thus free-up resources which are not going to be used

Plus other AMD changes still coming for Linux 6.13 by way of the x86 platform drivers and AMDGPU/AMDKFD kernel graphics driver changes, among updates in other subsystems too for AMD's growing variety of products.



[1] https://www.phoronix.com/search/Linux+6.13

[2] https://www.phoronix.com/news/Linux-6.13-Power-Management

[3] https://www.phoronix.com/news/AMD-3DV-Optimizer-Linux-6.13

[4] https://lore.kernel.org/lkml/20241118210508.GAZzusBLFPq3Rqt50z@fat_crate.local/

[5] https://www.phoronix.com/news/AMD-Hetero-Topo-Linux-6.13

[6] https://www.phoronix.com/news/AMD-HFI-Linux-Driver-v2

[7] https://lore.kernel.org/lkml/20241118160351.GAZztlZxg0V5LMzeUq@fat_crate.local/