Re: Packets dropped by virtual NICs
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