just in case someone missed the news for some months ago, Svalo
documented how to run LibreMesh in a virtual machine:
This is very very convenient for testing new features and playing with
the code without needing any router.
You will find there the explanation on the usage of plain QEMU or of the
graphical software Virt-Manager.
Up to now the documentation includes the setup of a single, isolated
LibreMesh virtual machine, any contribution to the documentation is welcome!