ACRN v3.0.1 (Jul 2022)

We are pleased to announce the release of the Project ACRN hypervisor version 3.0.1 with hot fixes to the v3.0 release.

ACRN is a flexible, lightweight reference hypervisor that is built with real-time and safety-criticality in mind. It is optimized to streamline embedded development through an open-source platform. See the What Is ACRN introduction for more information.

All project ACRN source code is maintained in the repository and includes folders for the ACRN hypervisor, the ACRN device model, tools, and documentation. You can download this source code either as a zip or tar.gz file (see the ACRN v3.0.1 GitHub release page) or use Git clone and checkout commands:

git clone
cd acrn-hypervisor
git checkout v3.0.1

The project’s online technical documentation is also tagged to correspond with a specific release: generated v3.0 documents can be found at Documentation for the latest development branch is found at

ACRN v3.0.1 requires Ubuntu 20.04 (as does v3.0). Follow the instructions in the Getting Started Guide to get started with ACRN.

What’s New in v3.0.1

Mitigation for Return Stack Buffer Underflow security vulnerability

When running ACRN on Alder Lake platforms that support RRSBA (Restricted Return Stack Buffer Alternate), using retpoline may not be sufficient to guard against branch history injection or intra-mode branch target injection. RRSBA must be disabled for Alder Lake platforms to prevent CPUs from using alternate predictors for RETs. (Addresses security issue tracked by CVE-2022-29901 and CVE-2022-28693.)

ACRN shell commands added for real-time performance profiling

ACRN shell commands were added to sample vmexit data per virtual CPU to facilitate real-time performance profiling:

  • vmexit enable | disable: enabled by default

  • vmexit clear: clears current vmexit buffer

  • vmexit [vm_id]: outputs vmexit reason code and latency count information per vCPU for a VM ID (or for all VM IDs if none is specified).

See ACRN v3.0 (Jun 2022) for additional release information.