libvirt users - Jun 2021 - interface qos conflicts with ovs

Hello community,

We found a strange situation where interface qos is being cleared up. After
some search, looks like ovs will clear tc setting at least on ingress.

related code is
https://github.com/openvswitch/ovs/blob/91cb55bc8aad7fe17060778482dc7ad18dc0d9a8/lib/netdev-linux.c#L2727

so I would like to know if it is more ideal to set ovs port qos and replace
current tc when ovs port is used? thank you

-- 

Best Regards,

Jiatong Shen
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On 6/11/21 2:02 AM, Jiatong Shen wrote:
> Hello community,
> 
> We found a strange situation where interface qos is being cleared up. After
> some search, looks like ovs will clear tc setting at least on ingress.
> 
> related code is
>
https://github.com/openvswitch/ovs/blob/91cb55bc8aad7fe17060778482dc7ad18dc0d9a8/lib/netdev-linux.c#L2727
> 
> so I would like to know if it is more ideal to set ovs port qos and replace
> current tc when ovs port is used? thank you
> 
Yes, this is known bug:

https://bugzilla.redhat.com/show_bug.cgi?id=1510237

Unfortunately, it hasn't gotten much attention. Libvirt should use ovs
to set up QoS instead of TC because ovs keeps the desired state of TAP
and will clear out anything that goes against it.

Michal