you where right, the networks adapters were connected to a PCI bus, only spice seems to be on the PCIE bus:
/usr/bin/kvm -id 901 -name 'Pfsense-test,debug-threads=on' -no-shutdown -chardev 'socket,id=qmp,path=/var/run/qemu-server/901.qmp,server=on,wait=off' -mon 'chardev=qmp,mode=control'...