[dpdk-dev] Problems with SR-IOV and transparent vlan under DPDK

Tom Kiely tkiely at brocade.com
Thu Nov 26 23:27:14 CET 2015


Hi,
     I wonder if anyone might have advice in relation to a major problem 
we're encountering.

We have an SR-IOV setup on Debian 8 with 4 VFs. Each VF is configured 
with transparent vlan 1000.

We have 4 VMs via KVM. 2xCentos (C1, C2) and 2xDebian8 (VR1, VR2) with 
DPDK based dataplane.

C1 can ping correctly to C2.

However, when C1 pings VR2, it fails because the received packets on VR2 
are tagged with the "transparent" vlan 1000.
VR2 is not configured for vlans and discards the packets.

All VMs are configured identically from the KVM perspective. SR-IOV VFs 
are attached using:

"virsh attach-device <domain> <xmlfile>"

where xmlfile is of the form:

<interface type='hostdev' managed='yes'>
      <source>
        <address type='pci' domain='0' bus='5' slot='16' function='3'/>
      </source>
     <vlan>
         <tag id='1000'/>
      </vlan>
    </interface>

"ip link show" shows the various VFs with the associated vlans.

$ ip link | grep vlan
     vf 0 MAC 52:54:00:68:cf:67, vlan 1000, spoof checking off, 
link-state auto
     vf 1 MAC 52:54:00:33:22:1a, vlan 1000, spoof checking off, 
link-state auto
     vf 2 MAC ba:10:05:10:00:03, vlan 1000, spoof checking off, 
link-state auto
     vf 3 MAC ba:10:05:10:00:04, vlan 1000, spoof checking off, 
link-state auto
     vf 0 MAC 52:54:00:fe:e0:6e, vlan 1000, spoof checking off, 
link-state auto
     vf 1 MAC 52:54:00:9c:f8:96, vlan 1000, spoof checking off, 
link-state auto
     vf 2 MAC ba:10:05:10:01:03, vlan 1000, spoof checking off, 
link-state auto
     vf 3 MAC ba:10:05:10:01:04, vlan 1000, spoof checking off, 
link-state auto


Wireshark on the Centos VMs show the correct packets being received but 
show the packets with the incorrect vlan header on the DPDK based VR1/2.

So my question is: How should DPDK deal with the transparent vlan 
handling ? Where should it be notifying the hardware to apply and strip 
the transparent vlan tags on traffic from and to the VMs ?

Any insights gratefuly received.

Thanks,
Tom




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