Virtualization: Who is Who?

Virtualization is everywhere. From cloud providers running millions of containers, to your laptop running Virtual Machines, to data centres powering enterprise applications, virtualization silently powers the modern computing world. But how does it actually work?

This session will unveil the jargons and technical architecture behind this revolutionary technology. Expect answers to your What, How and Who questions about:

1. What is a VMM?

2. What is a Hypervisor?

3. What are Type-1 and Type-2 Hypervisors?

4. What are the different virtualization techniques?

   • Passthrough

   • Full virtualization

   • Para virtualization

   • Hardware-assisted virtualization

   • I/O virtualization bottlenecks

5. What is VirtIO?

   • How does it solve the existing I/O virtualization bottlenecks?

   • What is VirtIO frontend? What is VirtIO backend?

   • Who is the VirtIO device? Who is the VirtIO driver?

   • How does VirtIO enable efficient data transfer for near-native performance?

   • What is a Virtqueue? Packed Virtqueues? Split Virtqueues?

6. What is an IOMMU?

   • What are Stage-1 and Stage-2 page-tables?

   • Who configures the IOMMU?

   • Why is it needed? Where does it fit in the picture?

   • How does it enable security and safety in mixed-criticality systems?

All the technology and examples discussed during the presentation will be FOSS projects (like Xen, KVM, QEMU, Linux Kernel etc.). My experience of writing VirtIO backend and frontend drivers for Mailbox I/O, as well as reviewing virtualization patches, will be shared as lessons learned.

The aim of this session is to unveil the technology and spark curiosity so that newcomers can identify where to start their contributions and developers can identify which components to fine-tune for performance improvements.

1. Understand the complete virtualization stack from CPU to I/O

2. Know the tradeoffs between different virtualization approaches

3. Understand how VirtIO achieves near-native I/O performance

4. Be able to read and understand hypervisor documentation and code

5. Have a roadmap for contributing to virtualization projects like Xen, KVM, QEMU, Linux Kernel etc.