Reducing The Virtual Memory Overhead in Nested Virtualization

Abstract

Virtualization has become a critical aspect of modern computing, and with the advent of virtualization-based containers, fast nested virtualization has become increasingly important. Nested virtualization is implemented by emulating virtualization capabilities to the guest host which can result in significant overhead. Another source of overheads in virtualization stems from the address translation mechanisms employed to implement virtualization, which usually causes a mix of slower address translation, frequently trapping guests, and loss of granularity in page tables. Our research focuses on using guest-managed physical memory with the use of per-VM memory tags for checking each VMs' access permissions.