The VMM is a key component of the VMware vSphere environment. It is a thin layer that provides virtual x86 hardware for a virtual machine's guest operating system. This hardware includes CPU, memory, network, storage, and so on. Each VMM is serviced to one virtual machine; it shares the CPU, memory, NIC driver, and I/O driver with the VM. The VMM can be configured using hardware virtualization, software virtualization, and paravirtualization techniques. Hardware virtualization and software virtualization will be discussed in the next section. Paravirtualization allows software running on a virtual machine to bypass the virtual interface. It runs the operation on the physical hardware.
The VMM can choose from three monitor modes:
Binary translation and shadow page tables
Intel VT-x or AMD-V and shadow page tables
AMD-V with RVI or Intel VT-x with EPT