Linux 6.5 Features From USB4 v2 To More WiFi 7, Unaccepted Memory, Scope-Based Resource Management
Now that the Linux 6.5 merge window ended this past weekend, here is the usual Phoronix overview that lists all the prominent new features and changes coming for this next version.
Linux 6.5 stable won't be stable until around the end of August, but it's another exciting cycle. The Linux 6.5 kernel has many exciting features in tow: initial support for USB4 v2 and Intel's new Barlow Ridge controller, more preparations for WiFi 7 wireless hardware, parallel CPU bring-up for x86 CPUs, a new cachestat() system call for querying page cache statistics, UEFI unaccepted memory, scope-based resource management infrastructure, more CXL features implemented, overclocking support for AMD Radeon RX 7000 series GPUs, MIDI 2.0 driver support, and even some improvements to the PS/2 mouse/keyboard driver code.
Linux 6.5 is all the more of an important release with Ubuntu 23.10 planning to use it among other early autumn Linux distribution releases. Let's move on with all the exciting Linux 6.5 kernel changes.
Processors:
- Parallel CPU bring-up support for modern Intel and AMD systems to help shorten the boot / Kexec reboot time on large servers.
- Linux now defaults to AMD P-State "active" EPP for Zen 2 and newer systems supporting this mode of operation leveraging ACPI CPPC.
- AMD Ryzen 7000 series EDAC support for enabling error detection and correction on capable Zen 4 consumer CPUs rather than just being limited to the AMD EPYC server CPU models.
- Enhanced load balancing for Intel hybrid CPUs.
- LoongArch added SMT and SIMD/Vector extensions for that Chinese CPU architecture.
- Support is added for the Alibaba T-Head TH1520 RISC-V CPU and a few new Arm SoCs too.
- Intel Speed Select updates around TPMI and cluster-level power controls.
- A CPU frequency scaling fix for Intel P-State with Intel Core hybrid CPUs when disabling E-cores to just leave the P cores online.
- UEFI Unaccepted Memory support that is useful for both AMD SEV-SNP and Intel TDX for postponing the acceptance of memory by VMs until it's needed post-boot in order to help tighten security, reduce overhead, and shorten boot times when dealing with encrypted VM memory.
- Intel SoundWire ACE2.x support for audio capabilities premiering with Intel Lunar Lake processors.
- AMD PerfMonV2 for KVM VMs, complementing the PerfMonV2 added already to the kernel a few cycles ago for Zen 4 CPUs.
- VFIO support for the AMD CDX bus.
- DEXCR support for IBM POWER10 CPUs for this Dynamic Execution Control Register that allows dynamically controlling execution behavior on a per-CPU basis.
- New AMD hardware support for their CPU's cryptographic co-processor (CCP).
- New Intel Meteor Lake S driver code.
- SNC for HPE SGI UV servers, a.k.a. Sub-NUMA Clustering will finally work on those servers.
- The kernel is now delaying x86 FPU initialization in the kernel boot process as part of a broader clean-up.
Graphics:
- The AMD EDAC/RAS code adds GPU/accelerator support with an initial focus on enabling the error detection and correction for AMD Instinct MI200 hardware.
- AMD FreeSync Video support is now enabled by default.
- AMD Radeon RX 7000 series overclocking support for those RDNA3 GPUs with SMU13 IP.
- Intel Variable Rate Refresh for eDP panels on laptops.
- VirtIO sync object support for Vulkan.
- Qualcomm Adreno 690 GPU support within the MSM DRM driver.