This software allow you to build simple networks of libvirt VMs, switchs (future:and real-world access) using VDE and QEMU/KVM. It's much simpler than GNS3 and is sufficient in my use case, it's somewhat like Marionnet (but still with less features...).
It is quick&dirty but might be useful for you, but keep in mind that it rely on a dirty virDomainQemuMonitorCommand based hack.
To use it create your VMs in the virt-manager (or any libvirt client), remove networks interfaces if you don't want libvirtd networking stack and use this app to network VMs using VDE.
Warning! Only i440FX chipset are supported, Q35 chipset does not support PCIe hotplugging and this one is the default in virt-manager.
This link won't break You need to remove nodes to delete links right now.
This project use the Meson Build System. It require GTK3, libvirt-glib-1.0 and a modern VDE installation.
One-liner installation (if you are happy to mess your system) :
meson build && ninja -C build && sudo ninja -C build installIf you don't want to mess your system, skip installation and run the built exe at build/guest-networkizer.