HARDWARE VIRTUALIZATION IN NESTED VIRTUALIZATION

Abstract — it is a software implementation that runs on computers to run different programs like a real physical machine. There are two classifications of Virtual Machines categorized by their use i.e. System Virtual Machine and Process Virtual Machine. Virtual Machine Monitor or Hypervisor is the software layer that provides virtualization. The operating system running on virtual machine is called guest operating system. From Operating System designs and development, Virtualization has great impact and importance. Different techniques are used in virtualization; each has its own implementations under certain circumstances. One technique is not truly efficient for other environment. Shared kernel, full kernel and hypervisor virtualization are different techniques that be used combined as well as independently. Nowadays the full virtualization with binary translation is the most effective and reliable technology used ever with great ease of use. VMware uses both full virtualization with binary translation and hardware assisted virtualization. We have discussed many types of virtualization techniques and their interrupt handling. How virtual machine works over host operating system is well explained in this review. In nested virtualization there is a lack of architecture support for multi-level virtualization. For this reason it has up to 10 % of overload. It is possible to overcome the overhead i.e. 6-10 % for nested virtualization and to find a better solution.