Re: [Qemu-devel] jumbo frames: needing some help

[Anthony Liguori]

address@hidden wrote:
> Hello, everyone!
>
> Sorry for the inconvenience, but as a part of my diploma thesis, I am 
> creating a virtual NIC for QEMU, in order to support a new cluster OS 
> of the university. (Saving the overhead caused by emulating real 
> hardware, it is not emulating an existing NIC.) Anyway, now it seems 
> to be working correctly, except for handling jumbo frames, which I 
> have to make available.

You would have to post your patch.  We seem to be able to handle jumbo 
frames nicely with virtio-net.

BTW, are you aware of virtio-net?  It has all of the properties that you 
are describing and it already exists for Linux and Windows.

Regards,

Anthony Liguori

> I connected two QEMU instances by -net socket,listen and -net 
> socket,connect options and I can send and receive packets in the 
> guests. If I'm sending a 9000 byte packet, or bigger than 4 kByte, it 
> is received completely by the other instance, but then QEMU crashes.
>
> I didn't find an according bug in the code of my NIC.
> MTU of 127.0.0.1 is 16436...
>
> Is there something special that I have to take care of, dealing with 
> jumbo frames? Unfortunately I'm no expert in networking...
>
> Thank you in advance!
>
> Regards,
>
> Martin Rauh.