It's not used anywhere, but should be pointing to
$sysconfdir/libvirt/libvirtd.conf, not $sysconfdir/libvirtd.conf
# define LIBVIRTD_PRIV_UNIX_SOCKET LOCALSTATEDIR "/run/libvirt/libvirt-sock"
# define LIBVIRTD_PRIV_UNIX_SOCKET_RO LOCALSTATEDIR "/run/libvirt/libvirt-sock-ro"
# define LIBVIRTD_USER_UNIX_SOCKET "libvirt-sock"
-# define LIBVIRTD_CONFIGURATION_FILE SYSCONFDIR "/libvirtd.conf"
+# define LIBVIRTD_CONFIGURATION_FILE SYSCONFDIR "/libvirt/libvirtd.conf"
/* Defaults for PKI directory. */
# define LIBVIRT_PKI_DIR SYSCONFDIR "/pki"