Software Update: Linux Kernel 5.8

Linus Torvalds has version 5.8 of the Linux Kernel released. The kernel is the heart of the operating system and, simply put, it sits as a layer between the hardware and the applications. New in version 5.8 includes an energy driver for the Zen and Zen 2 CPUs from AMD, support for Thunderbolt and the igp from the Intel Tiger Lake CPUs and Trusted Memory Zones in AMD GPUs, which enables access to encrypted video memory. More information about the improvements in this release can be found at Phoronix. Below is an overview of the main improvements in Linux Kernel 5.8:

graphics:

• Qualcomm Adreno 405/640/650 open source support.
• AMDGPU TMZ support with Trusted Memory Zones for encrypted video memory.
• Intel Tiger Lake SAGV support and other Gen12 graphics updates.
• Radeon Navi/GFX10 soft recovery support.
• The Radeon driver also now better handles critical thermal faults.
• P2P buffer/DMA support between GPUs.
• Other updates too like Lima run-time power management, Nouveau support for NVIDIA format modifiers, and more.

Processors:

• The AMD Energy Driver was merged for (finally!!!) exposing the Zen/Zen2 energy sensors on Linux.
• AMD Ryzen 4000 Renoir temperature and EDAC support.
• Nested AMD live migration with KVM is now supported.
• Loongson 3 CPU support for KVM virtualization.
• Specter mitigation fixes also being back-ported now to the stable series.
• Boost support for the CPPC CPUFreq driver.
• PCIe NTB support for Ice Lake Xeon servers.
• RISC-V Kendryte K210 SoC support has been wrapped up.
• New Arm SoC and platform support.
• Initial support for booting POWER10 processors.
• AMD Zen/Zen2 RAPL support for run-time average power limiting.
• Intel TPAUSE power-optimized delays support for Tremont cores and newer.
• Tightened Arm 64-bit security with now supporting Branch Target Identification (BTI) and the Shadow Call Stack.
• XSAVES supervisor states support, Memory Bandwidth Monitoring Counters, and other x86 (x86_64) updates.

Storage / File Systems:

• A block device back-end for Pstore in saving oops/panic messages to disk.
• ERASE/Discard/TRIM support for all MMC hosts rather than being opt-in previously.
• F2FS LZO-RLE compression support is added for this flash optimized file-system.
• Microsoft exFAT driver improvements courtesy of Samsung.
• Support for emulating MLC NAND flash memory as SLC.
• A performance optimization for Xen 9pfs.
• SMB3 performance work for large I/O.
• Fixes for EXT4.
• Improved DAX support for direct access to persistent memory storage.
• Various Btrfs improvements.

Other Hardware:

• Habana Labs Gaudi support for this AI inference accelerator.
• Intel Tiger Lake Thunderbolt support as well as ComboPHY support for Intel’s Gateway SoCs.
• Support for Thunderbolt on non-x86 systems.
• The possibility of significant power-savings for motherboards with PCIe to PCI/PCI-X bridges.
• Peer-to-peer DMA for AMD Raven and Renoir.
• AMD Renoir ACP audio support.
• Cable Testing Infrastructure in the Linux network code albeit initially limited to select hardware/drivers.
• Restoring the Intel Atom (AtomISP) camera driver.
• Support for swapping Fn and Ctrl keys on Apple keyboards.
• Numerous power management updates.
• AMD SPI controller driver was merged.

General Improvements:

• Jitter RNG improvements and landing of the Arm CryptoCell CCTRNG driver. AMD PSP SEV-ES support is also part of the crypto updates.
• The Kernel Concurrency Sanitizer has been merged with KCSAN helping to detect race conditions in the kernel and has already been used for uncovering dozens of real bugs.
• Staging and IIO updates.
• Scheduler Optimizations.
• A general notification queue initially wired up for notifying on key/keyring changes.
• SELinux optimizations.
• Modernization improvements for Procfs with now supporting private procfs instances.
• A new initrdmem= option that among other use-cases can be used when replacing Intel ME space with an initrd image in the saved flash area.
• L1d cache flushing on a per-context basis as an opt-in feature was originally merged. However, Linus Torvalds ultimately reverted it for now as in the current implementation is “beyond stupid”.