Comment 1 for bug 1960937

Digging into this a bit more, it looks like the libvirtd.service file needs to be changed to enable the tcp listener instead of using the /etc/default/libvirtd config file. Would be nice if the service had the tcp option (commented out by default)

My changes were to
Remove $libvirtd_opts because any setting here causes the service to fail at startup.
Add
Wants=libvirtd-tcp.socket
and
Also=libvirtd-tcp.socket

[Unit]
Description=Virtualization daemon
Requires=virtlogd.socket
Requires=virtlockd.socket
# Use Wants instead of Requires so that users
# can disable these three .socket units to revert
# to a traditional non-activation deployment setup
Wants=libvirtd.socket
Wants=libvirtd-ro.socket
Wants=libvirtd-tcp.socket
Wants=libvirtd-admin.socket
Wants=systemd-machined.service
Before=libvirt-guests.service
After=network.target
After=dbus.service
After=iscsid.service
After=apparmor.service
After=local-fs.target
After=remote-fs.target
After=systemd-logind.service
After=systemd-machined.service
After=xencommons.service
Conflicts=xendomains.service
Documentation=man:libvirtd(8)
Documentation=https://libvirt.org

[Service]
Type=notify
EnvironmentFile=-/etc/default/libvirtd
ExecStart=/usr/sbin/libvirtd $libvirtd_opts
#ExecStart=/usr/sbin/libvirtd -l -d
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
# At least 1 FD per guest, often 2 (eg qemu monitor + qemu agent).
# eg if we want to support 4096 guests, we'll typically need 8192 FDs
# If changing this, also consider virtlogd.service & virtlockd.service
# limits which are also related to number of guests
LimitNOFILE=8192
# The cgroups pids controller can limit the number of tasks started by
# the daemon, which can limit the number of domains for some hypervisors.
# A conservative default of 8 tasks per guest results in a TasksMax of
# 32k to support 4096 guests.
TasksMax=32768
# With cgroups v2 there is no devices controller anymore, we have to use
# eBPF to control access to devices. In order to do that we create a eBPF
# hash MAP which locks memory. The default map size for 64 devices together
# with program takes 12k per guest. After rounding up we will get 64M to
# support 4096 guests.
LimitMEMLOCK=64M

[Install]
WantedBy=multi-user.target
Also=virtlockd.socket
Also=virtlogd.socket
Also=libvirtd.socket
Also=libvirtd-ro.socket
Also=libvirtd-tcp.socket