This guide describes the virtualization support in Armv8-A AArch64. Topics covered include stage 2 translation, virtual exceptions, and trapping.
This guide includes some basic virtualization theory as an introduction, and gives some examples of how a hypervisor might use the features that it describes. It doesn't cover the operation of a specific hypervisor, or attempt to explain how to write your own hypervisor from scratch. Both subjects are beyond the scope of this guide.
At the end of this guide, you can check your knowledge. You will have learned about the two types of hypervisor and how they map on to the Arm Exception levels. You will be able to explain the operation of traps and how they can be used to emulate operations. And you will be able to list which virtual exceptions a hypervisor can generate and describe the mechanisms for doing this.
Before you begin
We assume that you have a basic understanding of virtualization, including what a Virtual Machine (VM) is as well as the role of the hypervisor. Familiarize yourself with the Exception model and address translation in Memory management.