The Xen livepatch framework provides a way to redirect calls to functions at runtime. It is useful when a running system needs to be updated without being stopped, for example to apply security fixes.
This session explores the possibility of extending this mechanism into a more tracing/debugging-friendly feature. Such an extension could allow more flexible use of existing Xen tracing tools such as xentrace. We will showcase this idea by sharing our recent experience using xentrace, and discuss how a callback-based extension could make similar investigations easier in general.
We would also like to discuss possible future extensions inspired by Linux tracing mechanisms such as kprobes/ftrace/eBPF which could make the feature more useful in practice.
