Xen Project 4.22 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:

• Support for per-domain Xenstore quota in C xenstored (includes xenstore-stubdom), libxl and xl.
• Support for Xenstore watch depth feature in C xenstored (includes xenstore-stubdom).
• x86: Support for Bus Lock Threshold on AMD Zen5 and later CPUs, used by Xen to mitigate (by rate-limiting) the system wide impact of an HVM guest misusing atomic instructions.
• x86: Support for CPIO microcode in discrete multiboot modules.
• x86: Introduce get-core-temp command to xenpm to query CPU temperatures on Intel platforms.
• Arm: Support for guest suspend and resume to/from RAM via vPSCI. Applies only to non-hardware domain guests.
• Arm: Continued Armv8-R MPU enablement.
• Arm: Drop ThumbEE support.
• Arm: FF-A v1.2 support.
• RISC-V: SSTC extension support for Xen (not for guest yet).
• RISC-V: Introduce domain build helpers (CONFIG_DOMAIN_BUILD_HELPERS) which allows to load Linux kernel, initrd and allocation related things for device tree-based domains, laying the groundwork for guest boot support.

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:

ARM

On Arm, Armv8-R MPU enablement is ongoing. The work will be included in the next few releases.

RISC-V

On RISC-V, support for booting dom0less guests is being added. The work will be included in the next few releases.