Xen Project Developer & Design Summit

The Xen hypervisor is a great fit for embedded, automotive and avionics, thanks to its lean architecture, small code base (even smaller on ARM), flexibility and security. Low interrupt latency is an essential requirement for many embedded use cases. Unavoidably, virtualization increases interrupt latency, but different Xen configurations lead to very different results.

This talk will explain how to achieve minimal interrupt latency. It will cover how scheduling interacts with interrupt delivery in Xen. It will introduce the new Xen "null" scheduler, designed for maximum determinism and minimum overhead on embedded platforms. Findings will be corroborated by showing interrupt latency numbers taken on Xen on ARM in various configurations, such as vCPU pinning, Credit 1 and 2, and null schedulers.