On 3/27/21 2:53 PM, Silvia Fichera wrote:> Hi all,
> I want to use tc qdisc settings in a network coposed of several qemu
> VMs, connected through bridges and tap interfaces.
> I generate traffic with a spirent. Everything is fine when the
> scheduling discipline is not installed but when I run the command to set
> taprio queues traffic on the VM's NIC the traffic is dropped, i can
send
> max 1mbps.
> I think that there is something missing in the virtual NIC configuration
> or setup. With ethtool i can see that queues are configured. I've also
> noticed the BQL equals to 0, that is different than the physical machine
> (BQL=18600) where everything works correctly.
> I've read that it could be because NIC drivers do not support that
setting.
>
> Do you have any suggestions?
Hey,
I'm not familiar with taprio, but what's implemented in libvirt is htb
and sfq and that works well. Are you setting qdisc-s yourself or
modifying libvirt created structure?
Are you setting these qdiscs from the host, right?
I know that when changing QoS settings (when libvirt changes qdics/class
layout) for a brief moment packets are not transmitted from/to guest. I
suspect that kernel is freeing up queues or something. But this does not
look like your case, does it?
Michal