I cant find any official documentation on what this setting enables but some people seem to be saying it enables Q in Q configuration. Is that accurate? If so - can someone give me an example of when you might use that?
vlan aware option is not related to QinQ.
it's enable vlan filtering on linux bridge ports, like ovs.
Classic linux bridge don't support vlans, that why we need to tag on ethx.y interface
classic bridge
--------------------
eth0------->vmbr0
then when you use vlan tag is vm configuration, proxmox create new bridges and tagged interfaces
eth0.100---->vmbr0v100
eth0.101---->vmbr0v101
vlan aware bridge
---------------------------
eth0----->vmbr0
then proxmox will tag ports of the vmbr0, with correct vlan.
ports of vmbr0 are vm tap interfaces (tapXiY)
eth0----->vmbr0---(vlan100)--->tapXiY
---(vlan101)---->tapXiY
(This is exactly the same than openvswitch)
Now for QinQ, it seem that it don't works fine for now with vlan aware bridge,
user have reported working configuration with
eth0.10---->vmbr0
then using vlan tag in vm configuration (100 and 101 for example),
proxmox will create new bridges like this
eth0.10.100--->vmbr0v100
eth0.10.101--->vmbr0v100
I'll try to update the wiki soon