Re: [bug] cxgb4: vrf stopped working with cxgb4 card

[AMG Zollner Robert <robert@cloudmedia.eu>]

On 19.06.2018 16:24, Ganesh Goudar wrote:
> On Monday, June 06/11/18, 2018 at 14:47:55 +0530, Ganesh Goudar wrote:
>> On Saturday, June 06/09/18, 2018 at 18:47:55 -0600, David Ahern wrote:
>>> Ganesh:
>>>
>>> On 6/4/18 9:03 AM, AMG Zollner Robert wrote:
>>>> I have noticed that vrf is not working with kernel v4.15.0 but was
>>>> working with v4.13.0 when using cxgb4 Chelsio driver (T520-cr)
>>>>
>>>> Setup:
>>>> Two metal servers with a T520-cr card each, directly connected without a
>>>> switch in between.
>>>>
>>>>         SVR1  only ipfwd                 SVR2     with vrf
>>>> .----------------------------. .----------------------------------.
>>>> |                            |         |             |
>>>> |    192.168.8.1 [  ens2f4]--|---------|--[ens1f4] 192.168.8.2   |
>>>> |    192.168.9.1 [ens2f4d1]--|---------|--<ens1f4d1> 192.168.9.2 VRF=10   |
>>>> `----------------------------' `----------------------------------'
>>>>
>>>> When vrf is not working there are no error messages (dmesg or iproute
>>>> commands), tcpdump on the interface (SVR2.ens1f4d1) enslaved in vrf 10
>>>> shows packets(arp req/reply) coming in and going out, but outgoing
>>>> packets(arp reply) do not reach the other server SVR1.ens2f4d1
>>>>
>>>>
>>>> Bisect:
>>>> Found this commit to be the problem after doing a git bisect between
>>>> v4.13..v4.15:
>>>>
>>>> commit ba581f77df23c8ee70b372966e69cf10bc5453d8
>>>> Author: Ganesh Goudar <ganeshgr@chelsio.com>
>>>> Date:   Sat Sep 23 16:07:28 2017 +0530
>>>>
>>>>      cxgb4: do DCB state reset in couple of places
>>>>
>>>>      reset the driver's DCB state in couple of places
>>>>      where it was missing.
>>>
>>> Are you working on a fix for this or should a revert of the above patch
>>> be sent?
>> Will look into it and fix/revert it soon, Thanks for responding to Robert.
>>>
>>>
>>>>
>>>>
>>>> A bisect step was considered good when:
>>>> - successful ping from SVR1 to SVR2.ens1f4d1 vrf interface
>>>> - successful ping from SVR2 global to SVR2 vrf interface trough SVR1(l3
>>>> forwarding) (this check was redundant,both tests fail or pass simultaneous)
>>>>
>>>> The problem is still present on recent kernels also, checked v4.16.0 and
>>>> v4.17.rc7
>>>>
>>>> Disabling DCB for the card support fixes the problem ( Compiling kernel
>>>> with "CONFIG_CHELSIO_T4_DCB=n")
>>>>
>>>>
>>>>
>>>> This is my first time reporting a bug to the linux kernel and hope I
>>>> have included the right amount of information. Please let me know if I
>>>> have missed something.
>>>>
>>>>
>>>>
>>>> Thank you,
>>>> Zollner Robert
>>>>
>>>>
>>>> --------
>>>> Logs:
>>>>
>>>> VRF configured using folowing commands:
>>>>
>>>> #!/bin/sh
>>>>
>>>> CHDEV=ens1f4
>>>> VRF=vrf-recv
>>>>
>>>> sysctl -w net.ipv4.tcp_l3mdev_accept=1
>>>> sysctl -w net.ipv4.udp_l3mdev_accept=1
>>>> sysctl -w net.ipv4.conf.all.accept_local=1
>>>>
>>>> ifconfig ${CHDEV}   192.168.8.2/24
>>>> ifconfig ${CHDEV}d1 192.168.9.2/24
>>>>
>>>> ip link add ${VRF} type vrf table 10
>>>> ip link set dev ${VRF} up
>>>>
>>>> ip rule add pref 32765 table local
>>>> ip rule del pref 0
>>>>
>>>> ip route add table 10 unreachable default metric 4278198272
>>>>
>>>> ip link set dev ${CHDEV}d1 master ${VRF}
>>>>
>>>> ip route add table 10 default via 192.168.9.1
>>>> ip route add 192.168.9.0/24 via 192.168.8.1
>>>>
>>>>
>>>>
>>>>
>>>
> -netdev, Please feel free to add if needed.
> 
> Hi Robert,
> 
> My knowledge of VRF is very limited, I am trying to bring
> up VRF setup, I just wanted to check if you are doing anything
> related DCB and also please let me know how did you setup SRV1.
> 
> Thanks
> 

Hello Ganesh,

SRV1 is just forwarding(l3) between the two physical ports of the 
T520-CR card.

ifconfig ens1f4   192.168.8.1/24
ifconfig ens1f4d1 192.168.9.1/24
sysctl -w net.ipv4.ip_forward=1

- No VRF is configured on this box
- DCB is also not used


SVR2 is using VRF and is configured with the script inlined in the first 
email.