ACRN Hypervisor Release Version 2.5

By June 29, 2021Blog

We are pleased to announce the release of ACRN™ hypervisor version 2.5.

What’s New in v2.5

Nested Virtualization Technology Preview

A brand-new concept, nested virtualization, is introduced as a preview in this v2.5 release. Nested virtualization lets you run virtual machine instances inside of a guest VM that’s running on the ACRN hypervisor. It’s designed to leverage the KVM/QEMU community’s rich feature set while keeping ACRN’s unique advantages in partition mode and hybrid mode. Read more in the Enable Nested Virtualization advanced guide.

Secure Boot Using EFI Stub

EFI stub, previously retired in favor of using direct boot, returns as an alternative to end-to-end secure boot with Grub. The hypervisor, Service VM kernel, and prelaunched VM kernel are packaged into a single acrn.efi blob as an EFI application that can then be verified by the EFI BIOS. Read more in the Enable ACRN Secure Boot With EFI-Stub and Enable ACRN Secure Boot With GRUB advanced guides.

Modularization Improvements

ACRN hypervisor modularization has been improved to be more scalable, including change to multiboot, interrupt handling, paging and memory management, and timers, with more to come in future releases.

Configuration and Build Process Improvements

The ACRN configuration and build process continues to evolve from the changes made in the previous releases. For instructions using the build system, refer to Build ACRN From Source. For an introduction on the concepts and workflow of the configuration tools and processes, refer to Introduction to ACRN Configuration.


See the v2.5 full release notes and documentation for more information about this release including fixed and known issues.