I am unsure what the problem might be.
On my system I installed libvirt then created a VM and it works.
I think the daemon remains idle until the user launches (powers on) the VM that was created but I never had to do anything else but launch the VMM from the menu then start the VM and it is always active.
I did have to install virt-manager to be able to create and manage the VMs from the desktop, but nothing else since all the libvirt packages were installed by default on my F37 system. If you look at the status of the libvirtd.service on F37 this is the default status.
Until you have created a VM and it is running this is what you will see.
The man page says this:
SYSTEM SOCKET ACTIVATION
The libvirtd daemon is capable of starting in two modes.
In the traditional mode, it will create and listen on UNIX sockets itself. If the --listen parameter is given, it will also listen on TCP/IP socket(s), according to
the listen_tcp and listen_tls options in /etc/libvirt/libvirtd.conf
In socket activation mode, it will rely on systemd to create and listen on the UNIX, and optionally TCP/IP, sockets and pass them as pre-opened file descriptors. In
this mode, it is not permitted to pass the --listen parameter, and most of the socket related config options in /etc/libvirt/libvirtd.conf will no longer have any ef‐
fect. To enable TCP or TLS sockets use either
$ systemctl start libvirtd-tls.socket
$ systemctl start libvirtd-tcp.socket
Socket activation mode is generally the default when running on a host OS that uses systemd. To revert to the traditional mode, all the socket unit files must be
Since Fedora uses systemd the last sentence there is important. It is started by the socket mode, and does not run constantly.