Re: [Qemu-discuss] [question] why only one vport in /dev/char/ when Iuse qemu option "-device virtio-serial, max_ports=2"

[Zhang Haoyu]

>Hi, Amit,
>I start a VM with the option "-device virtio-serial,max_ports=2", but only one 
>vport I can see in /dev/char/,
>I read the source, 
>
>guest virtio console driver                                                    
>  qemu virtio-serial
>
>virtcons_probe
>     |
>init_vqs
>     |
>__send_control_msg(
> VIRTIO_CONSOLE_DEVICE_READY)       =====>                         control_out
>                                                                               
>                  |
>                                                                               
>           handle_control_message
>                                                                               
>                  |
>                                                                               
>           QTAILQ_FOREACH(port, &vser->ports, next) {
>control_intr                                      <=====                       
>            send_control_event(VIRTIO_CONSOLE_PORT_ADD) } 
>     |
>control_work_handler
>     |
>add_port
>    |
>device_create("vport%up%u")
>
>And, I add debug log in virtser_port_device_realize(), find that 
>virtser_port_device_realize() was called only once,
>i.e., only one port in vser->ports,  why?
>
I got the reason, only one -device virtserialport configured, so only one port 
in vser->ports.
>How does max_ports option take effection ?
>
>Thanks,
>Zhang Haoyu