I tried to set cn=myMachine instead of cn=192.168.1.x
and...everything frezees! 
virsh -c qemu://.../system

tries to connect forever.

You really need static ip addresses in the cn field??
I think this is an HUGE bug: you are saying to me that each time I change network or ip (because, dear sirs, dhcp exists) I have to generate a whole new couple of certificates??
I hope it is not the case....

regards
Pasquale