1. help: show help message
2. list: list all available vdpa devices
3. create: create a new vdpa port with socket file and vdpa device address
- 4. quit: unregister vhost driver and exit the application
+ 4. stats: show statistics of virtio queues
+ 5. quit: unregister vhost driver and exit the application
Take IFCVF driver for example: