Guest-management stacks typically need the guest to communicate some information back. This essentially happens through Xenstore and some of has been normalized in the Xen docs.
Some of those pieces of information are filled by PV drivers (eg. ~/control/feature-poweroff), others like information on network configuration are more commonly filled by a userspace daemon (eg. xe-guest-utilities for XAPI-based platforms). People in need to publish such info even turn to forked old versions of those tools for lack of a central solution.
We have started to work on a prototype guest agent (written in Rust) with the goal of providing such an official guest service within the Xen Project, that would be easily portable and use low resources.
We would like to discuss the perimeter for such a tool and agree for a clear path for the project.