Re: How to debug packet sends to virtual functions

[Mats Liljegren <liljegren.mats2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

I have a follow-up on this:

ixgbe version 3.13.10-k
ixgbevf version 2.7.12-k

(These are what was provided by Ubuntu 13.10)

I tried the following sequence on the host, before starting the guest:
1) sudo rmmod ixgbe
2) sudo modprobe ixgbe max_vfs=2
3) sudo ifconfig em1 up  # This is the physical function
4) sudo ifconfig em1_0 192.168.2.2  # This is the virtual function
5) ping 192.168.2.1

I can see that the ping request reaches its target, and a reply is
sent back. But this reply is not received by the ping shell command.

Why?

Regards,
Mats

On Wed, Jan 29, 2014 at 6:56 PM, Mats Liljegren
<liljegren.mats2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> I'm trying to get a modified version of the l2fwd example running, and
> have problems with packets being silently thrown away. I can receive
> packets, and my printf's indicates that the packets are being sent to
> the correct port, using correct MAC address as source address. And
> still, the packets are lost.
>
> Since the port is a virtual function, it seems like I cannot use
> tcpdump on it to see the network traffic. There is nothing coming out
> of the cable (activity light not flashing, the receiving end running
> tcpdump does not see any traffic).
>
> I'm using two X540 with two virtual functions each. The application
> runs in a KVM/Qemu environmen.
>
> Any suggestions how to debug this?
>
> Regards,
> Mats