/usr/include/ is in libvirt-dev 4.0.0-1ubuntu8.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libvirt/
/usr/include/libvirt/libvirt-admin.h
/usr/include/libvirt/libvirt-common.h
/usr/include/libvirt/libvirt-domain-snapshot.h
/usr/include/libvirt/libvirt-domain.h
/usr/include/libvirt/libvirt-event.h
/usr/include/libvirt/libvirt-host.h
/usr/include/libvirt/libvirt-interface.h
/usr/include/libvirt/libvirt-lxc.h
/usr/include/libvirt/libvirt-network.h
/usr/include/libvirt/libvirt-nodedev.h
/usr/include/libvirt/libvirt-nwfilter.h
/usr/include/libvirt/libvirt-qemu.h
/usr/include/libvirt/libvirt-secret.h
/usr/include/libvirt/libvirt-storage.h
/usr/include/libvirt/libvirt-stream.h
/usr/include/libvirt/libvirt.h
/usr/include/libvirt/virterror.h