kvm vlan virtio problem

[Bryan Venteicher]

Hi,

----- Original Message -----
> Hi!
> 
> The same warning shows up in our setup:
> 
> Jan 21 23:40:46 host kernel: WARNING: at net/core/dev.c:1712
> skb_gso_segment+0x1df/0x2b0() (Tainted: G        W  ---------------   )
> Jan 21 23:40:46 host kernel: Hardware name: System Product Name
> Jan 21 23:40:46 host kernel: tun: caps=(0x1b0049, 0x0) len=4452
> data_len=4380 ip_summed=0
> [...]
> 
> KVM host: CentOS 6.3, Linux kernel 2.6.32-279.19.1.el6.x86_64
> VM guest: FreeBSD 9.1, virtio-kmod-9.1-0.242658
> 
> Disabling TSO on vtnet0 stops the warnings on the KVM host.
> 
> Is there any progress on this issue?
> 

Alright, I tried to recreate this on Ubuntu 12.10 without any luck. Please
describe your network configuration. 

On my Linux host, my VLAN interface looks like:

eth0.100  Link encap:Ethernet  HWaddr 6c:f0:49:05:2b:6d  
          inet6 addr: fe80::6ef0:49ff:fe05:2b6d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3119867 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3790183 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:166813040 (166.8 MB)  TX bytes:5435432448 (5.4 GB)

That is plugged into this bridge:

br100     Link encap:Ethernet  HWaddr 6c:f0:49:05:2b:6d  
          inet addr:192.168.99.101  Bcast:192.168.99.255  Mask:255.255.255.0
          inet6 addr: fe80::6ef0:49ff:fe05:2b6d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:14 errors:0 dropped:0 overruns:0 frame:0
          TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:876 (876.0 B)  TX bytes:1420 (1.4 KB)

With the tap device created by QEMU for my FreeBSD guest:

vnet1     Link encap:Ethernet  HWaddr fe:54:00:ec:4f:4e  
          inet6 addr: fe80::fc54:ff:feec:4f4e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:800284 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3119877 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:5238099122 (5.2 GB)  TX bytes:210492002 (210.4 MB)

All this tied together:

# brctl show br100
bridge name	bridge id		STP enabled	interfaces
br100		8000.6cf049052b6d	no		eth0.100
							vnet1

Does this approximate your configuration? What's the output of `ethtool -k`
for your VLAN, bridge, and vnet interfaces?

Bryan

> 	Best regards
> 		Franz
>