The host machine to create a Linux bridge called br - arg,
The host machine to create eth0.10
Create a vm and vm is created on eth0.10 and eth0.20, IP address, respectively 192.168.10.11/24 192.168.20.11/24
Binding vnet0, vm hosting eth0.10 to br - arg,
Hosting eth0 linked to the switch, switch configuration vlan10 and vlan20 gateway, 192.168.10.1 192.168.20.1

Whether can on the vm, please ping two gateways