Xen Developer and Design Summit 2019

Despite the popularity of the Xen hypervisor, there are very few tools capable of performing virtual machine introspection (VMI) on Xen guests — not even a full-featured debugger! This is in large part because Xen's VMI APIs are obscure and poorly documented; even among Xen developers, there are very few people who know how to use them. This has serious consequences for projects targeting Xen, as the lack of tooling makes it difficult to verify the correctness and security of software running on Xen. In this presentation, Spencer will introduce and explain Xen's VMI APIs in detail, with the goal of providing all the information necessary to construct fully-featured Xen VMI API clients and analysis tools. In doing so, he will share the hands-on experience he gained while developing his recently-released tool Xendbg, a feature-complete reference implementation of a modern Xen VMI debugger.