Virtualization challenges
In simple terms, the goal of processor virtualization is to run an operating system within a hypervisor, which itself either runs on the bare metal of a computer system or executes as an application under the control of another operating system.
In this section, we will focus on the hosted (type 2) hypervisor because this mode of operation presents a few additional challenges that a bare-metal hypervisor may not face because the type-1 hypervisor has been optimized to support virtualization.
In a type-2 hypervisor, the host operating system supports kernel and user modes, as does the guest operating system (in the guest’s perception). As the guest operating system and the applications running within it request system services, the hypervisor must intercept each request and translate it into a suitable call to the host operating system.
In a nonvirtualized system, peripheral devices such as the keyboard and mouse interact directly with...
