Re: [Qemu-devel] Connecting netdev to emulated nics.

[Peter Crosthwaite]

On Fri, Oct 16, 2015 at 5:24 AM, sai pavan <address@hidden> wrote:
> Hi Jason,
>
> On Fri, Oct 16, 2015 at 1:07 PM, Jason Wang <address@hidden> wrote:
>>
>>
>> On 10/16/2015 01:15 PM, sai pavan wrote:
>>> +Peter
>>>
>>> Hi Jason,
>>>
>>> On Thu, Oct 15, 2015 at 2:44 PM, Jason Wang <address@hidden> wrote:
>>>>
>>>> On 10/15/2015 02:36 PM, sai pavan wrote:
>>>>> Hi,
>>>>>
>>>>> I am debugging an issue, where through one of the nics I am not able
>>>>> to connect to dtcp.
>>>>> So to dig in deep, i was going thought net.c files, and ended-up
>>>>> understanding little.
>>>>>
>>>>> So can i know how does a netdev connects to nic.
>>>>>
>>>>> nd_table[] has some pointers for netdev devices. Where are this
>>>>> actually instantiated ? I am missing that part of the code.
>>>>>
>>>>> How do the netdevs and nic's have 1-1 connections.
>>>> You may want to have a look at set_netdev().
>>> Thanks this helped to see more regarding netdev.
>>>
>>> one more question, there are 4 Ethernet Controllers in the soc im working on
>>> https://github.com/qemu/qemu/blob/master/hw/arm/xlnx-zynqmp.c#L223
>>>
>>> Each having configure nic and netdev internally. But only one can
>>> automatically connect to dhcp. Each one is assigned default mac
>>> address, Do each of the mac needs to be pre-registered with internal
>>> dhcp.?
>>
>> I think this is because if you don't specify any net clients on cli,
>> qemu will use default network configuration that has a hub with two
>> ports, first ports is connected to a nic and second port were connected
>> to userspace network
>> (http://wiki.qemu.org/Documentation/Networking#User_Networking_.28SLIRP.29)
>> which implements dhcp. You can see the network topology through "info
>> networks" commands.
>>
>> E.g if you want to let all nics to be connected to the user networking,
>> you may want to use:
>>
>> -net nic -net nic -net nic -net nic -net user
>>

Is there a long form of this CLI that does not rely on positional arguments?

Regards,
Peter

>> in your cli.
> Cool, This worked. Thanks !!
>
> Another question, is a way we can connect a particular device to hub,
> not connecting all ?
>
> Thanks,
> Sai Pavan
>>
>>>
>>> Regards,
>>> Sai Pavan
>>>
>>>>> And if my SOC has more than 1 sysbus type ethernet chips. How can i
>>>>> connect each one of them from command line ?
>>>> You can do this by using hubport as nic's peer e.g:
>>>>
>>>> -netdev hubport,id=port0,hubid=hubid -device e1000,netdev=port0
>>>>
>>>>> Regards,
>>>>> Sai Pavan
>>