Xen 4.22 Hypervisor Launch

After 8 months of development, the Linux Foundation has published the release of the free hypervisor Xen 4.22. Companies such as Amazon, Arm, EPAM Systems, and AMD participated in the development of the new release. The updates for the Xen 4.22 branch will continue until August 2029, with the publication of vulnerability fixes scheduled until August 2031. The project code is written in C and is distributed under the GPLv2+ license. Development is carried out as part of the Linux Foundation.

Key changes in Xen 4.22 include:

• The C version of xenstored, the libxl library, and the xl utility now have the ability to set quotas for resources in the Xenstore storage allocated to each domain. Commands such as “xl xenstore-quota-get” and “xl xenstore-quota-set” have been introduced for this purpose.
• The C version of xenstored has added the ability to limit the nesting depth when tracking changes in Xenstore.
• Support for limiting the intensity of bus locks (Bus Lock Threshold) for AMD Zen5 processors has been implemented.
• For x86 systems, the ability to download microcode updates from archives in CPIO format has been added.
• The “get-core-temp” command has been added to xenpm for requesting data on CPU temperature on Intel platforms.
• For ARM systems, the ability to put virtual machines into standby mode with saving the state in RAM via the vPSCI interface has been implemented.
• Continued adaptation for processors, such as Armv8-R, using a memory protection unit (MPU) instead of a classic memory management unit (MMU).
• Discontinuation of support for the ARM extension ThumbEE.
• Added support for the FF-A 1.2 specification (Firmware Framework for Arm A-profile).
• For RISC-V systems, support for the SSTC (Supervisor-mode Standard Timer Extension) extension has been added on the hypervisor side.
• For RISC-V systems, support for connecting handlers for building environments for virtual machines has been implemented, allowing for the automation of loading the Linux kernel and initrd.