How the Xen Hypervisor Supports CPU Virtualization on ARM

Early computer architectures, like the first Acorn RISC Machine pictured in Figure 0, had no support for CPU virtualization. In the 30 years since, processor designers have added new hardware components to fully enable virtualization.

This article explores how the Xen hypervisor supports CPU virtualization on modern ARM processors. We will start with a short background on virtualization and Xen, followed by a discussion of how ARM supports CPU virtualization with the virtualization extensions and finishing with a discussion of how Xen utilizes these features.

We are focused specifically on the ARMv8 architecture, commonly referred to as AArch64, and systems that support the ARM virtualization extensions. We will be assuming that a device tree is used for hardware discovery as is the case for nearly all embedded ARM devices.

VirtualizationMatthew FahrenkrugMarch 3, 2020Xen, Virtualization, Arm

Deep Dive: MMU Virtualization with Xen on ARM

This article will explore how the Xen hypervisor uses the Memory Management Unit (MMU) on ARM architecture to support virtualization. We’ll take a brief look at the history and purpose of the MMU then dive into Xen specifics, focusing on the ARMv8 implementation.

VirtualizationGreg PearsonFebruary 18, 2020Xen, Arm, Virtualization