How can you use the ARM instruction set for virtualization?

1 What is the ARM instruction set?

The ARM instruction set is a family of ISAs that are widely used in mobile devices, embedded systems, and servers. The ARM instruction set is based on a reduced instruction set computing (RISC) design, which means that it uses simple and efficient instructions that can be executed faster and with less power consumption than complex instruction set computing (CISC) designs. The ARM instruction set also offers different versions and extensions that can optimize performance, security, and functionality for different applications and platforms.

2 What are the types of virtualization?

Virtualization can be classified into two main types: hardware-assisted virtualization and software-based virtualization. Hardware-assisted virtualization relies on special features in the processor that enable the hypervisor or virtual machine monitor (VMM) to manage the virtual machines (VMs) and their access to the hardware resources. Software-based virtualization uses software emulation or translation to create and run the VMs, without requiring any hardware support. Both types of virtualization have their advantages and disadvantages, depending on the use case and the workload.

3 How does the ARM instruction set support hardware-assisted virtualization?

The ARM instruction set supports hardware-assisted virtualization through two features: the virtualization extensions and the TrustZone technology. The virtualization extensions, introduced in the ARMv7-A and ARMv8-A architectures, provide a new execution mode called hyp mode, which allows the hypervisor to run with higher privileges than the guest operating systems. The virtualization extensions also provide mechanisms for trapping and handling virtualization-related events, such as interrupts, exceptions, and memory accesses. The TrustZone technology, available in most ARM processors, creates a secure environment for the hypervisor and the secure VMs, isolating them from the normal world. The TrustZone technology also enables secure boot, secure storage, and secure communication for the virtualized system.

4 How does the ARM instruction set support software-based virtualization?

The ARM instruction set supports software-based virtualization through two features: the Thumb-2 instruction set and the Advanced SIMD extensions. The Thumb-2 instruction set, available in the ARMv6T2 and later architectures, is a 16-bit subset of the ARM instruction set that can be mixed with 32-bit instructions. The Thumb-2 instruction set can improve the code density and the performance of software emulation or translation, as it reduces the number of instructions and the memory footprint of the VMs. The Advanced SIMD extensions, also known as NEON, are a set of instructions that can perform parallel operations on vectors of data. The Advanced SIMD extensions can enhance the performance of software-based virtualization, as they can accelerate the emulation or translation of multimedia, graphics, and floating-point operations.

5 What are the benefits of using the ARM instruction set for virtualization?

Using the ARM instruction set for virtualization can offer several advantages, such as lower power consumption and higher energy efficiency, due to its design for low-power and high-performance devices. Moreover, it provides higher scalability and flexibility, as it can support a wide range of devices from smartphones to servers, and can adapt to different workloads and requirements. Additionally, the ARM instruction set is highly secure and reliable, leveraging TrustZone technology and virtualization extensions to protect the hypervisor and VMs from malicious attacks and hardware failures. Furthermore, it offers higher compatibility and portability, being able to support various operating systems and applications, as well as using software-based virtualization to emulate or translate other ISAs.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?