Virtfs will log all actions carried out if you have configured it so within the virt.conf file. Set Log = on and then specify the file for you to log all your actions in under Log File.
Virtuald will, by default, log actions by services requested through syslogd. I say by default, as you can shut off the logging by editing the source of virtuald.c and shutting off VERBOSELOG. By default it is on.
You will notice in your syslog when Virtuald kicks in. Something like this should be logged:
virtuald[4207]: Virtuald Starting v.xxxx
....
You will be able to tell where the service is being called to. Also, you may check on these logs for debugging purposes.
The logging for this modified version of virtuald is the same as the logging for virtuald (described above), except you will know which version of virtuald will be running (ie. tcpd enabled ot not):
virtuald[4220]: Virtuald Starting (tcpd enabled) v.xxx