[libvirt] [RFC] cgroups net_cls controller implementation

[Daniel P. Berrange]

On Thu, Dec 02, 2010 at 02:47:15PM +0100, D. Herrendoerfer wrote:
> This a basic implemantation to support the net_cls feature of
> cgroups. It adds the setting of a net_cls.classid value to the
> existing cgroups setup in the qemu driver.
> The classid is specified in the qemu.conf file.
> 
> This enables the use of the tc utility to manage traffic from/to
> vitual machines
> based on the setting combination of classid and network interface.

I don't think this patch is a good approach. The goal of libvirt is
that you can configure & control guests using terminology & APIs
that are platform & hypervisor independent. This precludes exposing
classid as a direct concept. Requiring the half the configuration
job to be performed via the tc command line utility is also not a
viable solution for apps that are communicating with libvirt over
a remote connection.

If we were to support this patch in libvirt, then it would make it
harder for us to incorporate a alternative solution for networking
traffic controls without causing behavioural regressions for anyone
who had started depending on this patch.


Regards,
Daniel