More information; 2.4 / FreeBSD 11.0 reliably crashes when more than 3 virtual network interfaces are added.
Configuration used:
name = 'firewall'
bios = "ovmf"
uuid="11d1366c-40e2-43b2-83be-52cfe0c6542d"
builder = 'hvm'
memory = '2024'
vcpus = 4
disk = ['file:/dev/hypervisor-local/firewall-system,xvda,w']
vif = [
'mac=00:16:3e:e5:68:fd, bridge=wan0, script=vif-openvswitch-no-offload, type=vif',
'mac=00:16:3e:e8:20:db, bridge=lan10, script=vif-openvswitch-no-offload, type=vif',
#'mac=00:16:3e:ee:02:44, bridge=lan20, script=vif-openvswitch-no-offload, type=vif',
#'mac=00:16:3e:e1:03:f1, bridge=lan30, script=vif-openvswitch-no-offload, type=vif',
'mac=00:16:3e:e2:30:44, bridge=lan40, script=vif-openvswitch-no-offload, type=vif'
]
boot = 'c'
serial='pty'
The VIF lines define network interfaces, when using the 3 as described in this configuration pfSense works, when adding one or more beyond that, it always crashes. With 4 it generates a panic and dump, with 5 it just panics and hangs in kdb with db>.