Re: [Qemu-discuss] Help in understanding the "info network"

[Thomas Huth]

On 06.01.2017 06:53, boddu pavan wrote:
> <mailto:address@hidden>
> Hi,
> 
> I am woking with xilinx zynqmp soc. On the qemu console "info networks"
> gives below log.
> 
> (qemu) info network
> hub 0
>  \ hub0port2: address@hidden: index=0,type=nic,
>  \ hub0port1: address@hidden: index=0,type=nic,
>  \ hub0port0: address@hidden: index=0,type=nic,
> address@hidden: index=0,type=nic,
>  \ user0: index=0,type=user,net=10.0.2.0,restrict=off
> 
> and my command line is like  -net nic -net nic -net nic -net
> nic,netdev=user0 -netdev user,id=user0.
> 
> I have two questions:
>     1) according to above log, is user0 network connected to hub0 ?. Can
> the other interfaces access user network ?

No, you did not configure a netdev for the hub0 (aka vlan0) network in
this case. Actually, you should see some warning messages in the
terminal where you started in this case, like this:

 Warning: vlan 0 is not connected to host network

If you see such warning messages, you can be sure that something is not
configured properly. (note: "vlan0" is not a VLAN in the traditional
sense, in QEMU-net-talk this means a hub device, i.e. in this case the hub0)

>     2) As the ethernet controller is sysbus devices, Im not able to
> create it with -device DEVNAME...
>         using -net nic i can either specify vlan number or netdev id.
> How can i connected it to one of the port on hub0 ?

If you want to hook up all the NICs to one user network, I think you
could do something like this:

 qemu-system-arm ... -net nic,vlan=0 -net nic,vlan=0 -net user,vlan=0

But using "vlan=..." is rather deprecated nowadays, I think it's better
if you'd specify separate user netdevs instead:

 qemu-system-arm ... -net nic,netdev=u0 -netdev user,id=u0 \
                     -net nic,netdev=u1 -netdev user,id=u1

Hope that helps,
 Thomas