Hardware Virtualization is the creation of virtual machines and environments based on the processor and its features.
This approach allows you to create multiple isolated virtual systems on the same hardware.
Hardware virtualization (HV) can only be used on processors that support the Virtual Machine Extension (VMX) instruction set. They provide direct access from the OS virtual machines to the CPU resources. These operating systems are also called «guest» operating systems as they run in a virtual setting.
Specialized software called Hypervisor is used to create virtual machines. It just splits up guest operating systems into independent objects which share the common resources of the server.
The advantage of this split is that the virtual machines can’t affect the speed of the others and change the amount of resources allocated.
Any hardware virtualization must provide the following functions for stable operation:
- Processor virtualization. All technologies and instructions available to the actual processor become available to the virtual processor as well.
- Graphical representations. Virtualization provides guest OS access to the graphics adapter and its functions separately.
- Input/Output (I/O). Hypervisor shares access to I/O devices and other peripherals between virtual systems without causing disruptions or glitches.
Intel and AMD
Hardware virtualization was started first by two competing companies, Intel and AMD. The technologies are called Intel-VT and AMD-V, respectively. There is a significant difference between the two.
When using Intel processors, software (Virtual Machine Monitor/Manager, VMM) is run first which activates virtualization mode. Administrators then work only through VMM and create virtual machines.
AMD uses its own Direct Connect technology. Once it’s launched, the VMM views all operating systems that are running on hardware with an AMD processor as guests.
Hardware virtualization provides reliable and stable virtual machine creation on the same physical hardware. In 2021, all Intel and AMD processors support hardware virtualization with the necessary instruction set.