Linux 6.4 Features: Many Intel & AMD Additions, Better Desktop/Laptop Hardware Drivers
With Linux 6.4-rc1 released, here is my original overview of all the interesting changes coming for the Linux 6.4 kernel that will be released as stable at the end of June or in early July.
As the Linux 6.4 merge window is over, it's time to begin testing this new kernel (and in my case, benchmarking it for any interesting improvements or regressions) over the next roughly eight weeks. Among the highlights for Linux 6.4 are early and still work-in-progress Apple M2 support, the new Qualcomm QAIC accelerator driver, Intel LAM, RISC-V system hibernation, Turtle Beach gaming controller support, more Rust language code has been upstreamed, sensor monitoring support for more than 100+ more ASUS motherboards, and an MSI laptop EC driver for improving support for various MSI laptop features under Linux. There is also a new IEEE-1394 Firewire maintainer with a promise to maintain the code until 2029 at least.
On the Intel side the Linear Address Masking is exciting, Sierra Forest EDAC support is added, initial Lunar Lake audio support, various new hardware IDs added, and Intel Shadow Stack support was submitted but then ultimately delayed due to last minute issues. On the AMD side there is now Guided Autonomous Mode support, AMD CDX bus support, VNMI, AMD SoundWire manager, 5-level guest page table support for its IOMMU driver, EDAC preparations for eventual AMD GPU support, and AMD SEV-SNP vTOM guest on Microsoft Hyper-V.
Here is a look at all of the exciting Linux 6.4 changes and new features. Stay tuned to Phoronix now for Linux 6.4 benchmarking over the coming weeks.
Processors:
- Intel Linear Address Masking has landed with this "LAM" functionality allowing for user-space to store metadata within some otherwise unused bits of pointers.
- Intel Shadow Stack was submitted for the Linux 6.4 merge window but last minute issues led to it not being pulled and is now delayed until at least the Linux 6.5 cycle.
- AMD Guided Autonomous Mode support within the AMD P-State driver.
- Virtual NMI for AMD CPUs with KVM virtualization.
- RISC-V supports hibernation / suspend-to-disk support ahead of any RISC-V laptops and the like heading to market.
- Removal of Intel Thunder Bay SoC support>
- More optimizations and new features for LoongArch.
- The AMD IOMMU driver now supports 5-level guest page tables.
- Intel EDAC support for Sierra Forest and in turn confirming that the E-core-only Xeon CPUs will feature a 12-channel DDR5 memory controller like with Granite Rapids.
- AMD SEV-SNP vTOM guest support on Microsoft Hyper-V.
- Initial Apple M2 support though this early Apple M2 SoC and device support isn't yet usable on the mainline kernel for end-users.
- AMD CDX bus support for interfacing between APUs and FPGAs.
Graphics Drivers:
- A new deadline hint for fences to influence the GPU performance/frequency.
- Continued Intel Meteor Lake graphics enablement.
- Early AMD work on the new "GFX943" accelerator IP.
- The Qualcomm QAIC accelerator driver was mainlined into Linux 6.4.
- 4K display support with the Rockchip DRM driver.
- The AMDGPU driver has new power features for the Steam Deck.
Storage & I/O:
- Concurrent I/O performance optimizations for Device Mapper.
- Pipe FMODE_NOWAIT support is good news for IO_uring and can yield a nice performance improvement.
- A number of improvements to EROFS.
- NFS server support for RPC-with-TLS.
- Small optimizations to the NTFS driver.
- Various F2FS and Btrfs improvements.
- Performance optimizations for EXT4.
Other Hardware:
- Intel Lunar Lake HD audio support.
- A new Firewire / IEEE-1394 maintainer.
- More WiFi 7 support work and many other networking changes including initial WiFi support for Apple M1 Pro and Apple M1 Max devices.
- AMD SoundWire support was added for use with the latest AMD Audio Co-Processor (ACP) IP blocks.
- Turtle Beach and Qanba gaming controller support with the XPad driver.
- Dropping of old USB drivers and removing the old PCMCIA char drivers as part of the spring cleaning and beginning to remove old CardBus/PCMCIA code.
- Fixing an issue where Intel USB support could be broken after resume.
- Continued bring-up of CXL, the Compute Express Link specification.
- Support for more Kye/Genius drawing tablets.
- Fixing an issue where Nintendo controllers could rumble indefinitely.
- Better MSI laptop support thanks to the new MSI EC driver.
- Apple GMUX support for T2 Macs.
- Apple M1/M2 keyboard backlight support.
- A new mode switch driver for Lenovo Yoga laptops.
- Sensor monitoring support for 100+ more ASUS desktop motherboards.
Linux Security:
- Optional CA enforcement of the machine keyring.
- SELinux removes run-time disabling support.
Other Linux 6.4 Kernel Changes:
- Faster performance for VDUSE.
- Linus Torvalds cleaned up the x86 memory copy code.
- More Rust code has been upstreamed in working toward finally having the first usable Rust drivers appear soon.
- Scheduler updates fix a database server performance regression.
- The SLOB removal finally happened.
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