Currently beta versions of both SLES 15 SP3 and openSUSE 15.3 are available for broader testing. In doing so I stumbled over a nasty bug in Autoyast, SUSE’s solution for automatic OS installations, when using the rules.xml mechanism:
Coexistance of SuSEfirewall and libvirt – restoring libvirt’s firewall rules automatically
Running libvirtd on openSUSE, you might eventually run into the situation that your KVM guests sooner or later lose network connectivity to the outside world, if some interface on the KVM host goes up or down or SuSEfirewall is run for some other reason, eg. manual restart.