The Illusion of Hardware: How Modern Virtual Machines Work

This talk provides an overall introduction to virtualization technology. The speaker begins with the basic concepts and a brief history of virtualization, introducing virtual machines and hypervisors. We then introduce memory virtualization and address translation, including virtual memory, paging, and the roles of the MMU and TLB.

Next, we show how virtual machine executes guest system's instructions through direct execution, enabled by hardware-assisted virtualization such as KVM and Virtualization.framework. We contrast this with emulation approaches, including interpretation and JIT compilation.

Finally, we discuss I/O virtualization, focusing on VirtIO. We show how emulators and hypervisors such as QEMU and ARCN efficiently virtualize devices, including disks, input devices, and graphics, through VirtIO.

By the end of this session, the audience will have a clear mental model of how modern VMs and containers work under the hood.