Xen Project 4.20 Feature List
Notable Features
This release has seen the increase in hardware support for both x86 and Arm, together with the addition of other improvements and features:
- ARM: Support for LLC (Last Level Cache) coloring.
- ARM: Experimental support for Armv8-R.
- ARM: Support for NXP S32G3 Processors Family and NXP LINFlexD UART driver.
- ARM: Basic handling for SCMI requests over SMC using Shared Memory, by allowing forwarding the calls to EL3 FW if coming from hwdom.
- x86: Support for Intel EPT Paging-Write Feature.
- x86: AMD Zen 5 CPU support, including for new hardware mitigations for the SRSO speculative vulnerability.
- x86: Removed support for running on Xeon Phi processors.
- x86: xl suspend/resume subcommands.
- x86: `wallclock` command line option to select time source.
- x86: Switched the xAPIC flat driver to use physical destination mode for external interrupts instead of logical destination mode.
- x86: Removed the `ucode=allow-same` command line option.
- x86: Removed x2APIC Cluster Mode for external interrupts. x2APIC Physical and Mixed Modes are still available.
- The dombuilder in libxenguest no longer un-gzips secondary modules, instead leaving this to the guest kernel to do in guest context.
- Reduce xenstore library dependencies.
Ongoing activities
The Xen community has several interesting initiatives, where work is ongoing and is expected to bear fruit in forthcoming releases. Some of the highlights:
- MISRA compliance improvements.
ARM
On Arm, PCI-passthrough work is ongoing, including some refactoring and improvements of the existing code. The work will be included in the next few releases.
RISC-V
On RISC-V, setup memory management and basic device tree mapping and parsing was introduced. In the next few releases full Xen build, AIA driver for hypervisor to support UART interrupts.