Question about encryption and tls

(Posted few days ago on qemu group but no reactions) Do I understand correctly that ssl shoudl be configured independently for libvirt and each hypervisor? I asked because I configured libvirt connection as qemu+tls://bambus.kjonca/system?pkipath=... (and on bambus in /etc/libvirt/libvirtd.conf) I set key_file = ... cert_file = ... ca_file = ... But after connect and lauching (on bambus) vm I tried to snif traffic to bambus:5900 on client) and wireshark was able to detect "VNC" protocol (BTW not spice?), so I am confused. should I configure in /etc/libvirt/qemu.conf spice_tls option and certificates ? KJ