Re: [Qemu-devel] [Qemu-discuss] Throttle in virtio-net

[Pradeep Kiruvale]

Hi Alberto,

Thanks for your reply.

>
> > I am planning to implement throttling functionality for virtio-net
> > driver using the throttling APIs that exist inside qemu.
>
> Hi Pradeep,
>
> the problem with implementing throttling for the network is that
> it's useless if you use the vhost_net kernel accelerator, because it
> bypasses QEMU entirely:
>
>    https://access.redhat.com/documentation/en-US/Red_Hat_
> Enterprise_Linux/7/html/Virtualization_Tuning_and_Optimization_Guide/sect-
> Virtualization_Tuning_Optimization_Guide-Networking-
> Virtio_and_vhostnet.html


Thanks for this very valuable information. What if someone wants to just
use virtio-net without the vhost acceleration?
Any idea how it will be done in this case? It still uses cgroup or some
other mechanism to do throttling?

>
> libvirt implements this using tc:
>
>    https://libvirt.org/formatdomain.html#elementDomain
>    http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm#ceiling


Here it uses the cgroup inside the libvirt dirver to control the packet
rate right?

Thanks,
Pradeep