Project ACRN has released v2.0 of its open source IoT and automotive hypervisor with a new hybrid-mode architecture for simultaneous deployment of safety critical and resourcing sharing VMs. ACRN v2.0 also adds OpenStack and Kata support.

In 2018 when the Linux Foundation launched its Project ACRN for developing a lightweight hypervisor for safety critical embedded applications, the chief use case was an automotive system in which safety critical functions are the dominant concern. With ACRN v2.0, the project focuses more on IoT applications that require a mix of safety critical and more general purpose Virtual Machines (VMs).

The new release offers a more flexible hybrid-mode architecture and “new and improved scenario definitions, with a focus on industrial IoT and edge device use cases,” says the project. The hypervisor enables deployment of typically RTOS-driven safety critical VMs for applications such as robotics and PLCs along with less critical tasks typically powered by Linux such as HMIs and machine learning. Despite this added flexibility, ACRN still enables “complete VM resource partitioning required for functional safety,” says the project.

ACRN v2.0 hybrid-mode architecture
(click image to enlarge)

ACRN v2.0 now supports both partition mode and sharing mode simultaneously. As shown in diagram above, you could run a pre-launched user VM for robotics and PLCs running an RTOS like Zephyr that can run independently of the other VMs and can use its own dedicated hardware resources. Such a pre-launched VM could be designated as a safety critical VM that could run platform hardware failure detection code and take emergency actions if in case of critical failure.

Meanwhile, the other VMs for higher end functions could continue to share resources and offer device sharing services using the same hypervisor. This block of non-safety critical VMs could also integrate a post-launched real-time VM (RTVM) “that can run a hard real-time OS, such as VxWorks, Zephyr, or Xenomai,” says the project.

The other key enhancement in ACRN v2.0 is new support for workload management and orchestration, thereby allowing open source orchestrators such as OpenStack to manage ACRN VMs. ACRN also adds support for secure container runtimes such as Kata Containers orchestrated via Docker or Kubernetes.

ACRN 2.0 features include:

• ACRN architecture upgrade to support hybrid mode
• New hardware platform support
• Pre-launched Safety VM support
• Post-launched VM support via OVMF
• Post-launched feal-time VM support
• Real-time VM performance optimizations
• CPU sharing support
• Large selection of OSes for user VMs
• GRUB bootloader
• SR-IOV support
• Both passthrough and shared graphics support
• Shared memory based inter-VM communication
• Configuration tools support
• Kata Containers support
• VM orchestration
• Improved documentation

In addition, the project has added support for Intel’s 8th Gen Whiskey Lake processors to join 7th gen Kaby Lake and Apollo Lake as verified platforms. The Whiskey Lake reference platform is Maxtang’s Linux-ready WL-10 thin Mini-ITX board.

Maxtang’s WL-10
(click image to enlarge)

ACRN also announced it has received concept approval from TÜV SÜD Rail GmbH for its functional safety concept, design and management process. The ACRN Hypervisor fulfills the requirements in accordance with SIL 3 of the IEC 61508 standard, says TÜV SÜD. The final functional safety certification is expected by year’s end.

Based on Intel technology, the BSD-licensed ACRN Hypervisor and device model provides workload prioritization for real-time and safety-criticality functions. Aside from Intel, other founding members include Adlink, LG, and Chinese IT services giant Neusoft. Exceed and TTTech have since joined the group. ACRN is one of many open source hypervisors supported by the virtualization framework of the Linux Foundation’s Automotive Grade Linux, as shown in this Project ACRN scenario.

The lightweight hypervisor runs on less than 40K lines of code compared to more than 150K for datacenter-centric hypervisors, says the project. ACRN offers low latency, fast boot time, and prioritization and isolation of safety critical workloads and can virtualize specific IoT functions including graphics, imaging, and audio. The hypervisor supports a wide range of VM OSes including Android, Windows 10, Ubuntu, VxWorks, and Zephyr.

“The fourth industrial revolution, characterized by a fusion of disruptive technologies, requires agility and the ability to consolidate heterogeneous workloads, some of which carry very strict requirements of Functional Safety certification or Real-Time behavior,” stated Rina Raman, VP and GM of Intel’s Embedded Acceleration Division. “With its 2.0 release, Project ACRN is now offering an open source hypervisor that makes such workload consolidation possible.”

 
Further information

ACRN v.20 is available now for free download. More information may be found Project ACRN’s announcement and release notes.

 
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