Re: [Qemu-devel] [PATCH v2 1/2] net: introduce MAC_TABLE_CHANGED event

[Michael S. Tsirkin]

On Thu, May 16, 2013 at 08:58:38AM -0600, Eric Blake wrote:
> On 05/16/2013 06:17 AM, Michael S. Tsirkin wrote:
> > On Thu, May 16, 2013 at 07:07:24PM +0800, Amos Kong wrote:
> >> Introduce this new QMP event to notify management after guest changes
> >> mac-table configuration.
> >>
> > 
> > This makes it easy for guest to flood management with
> > spurious events.
> > How about we set a flag after this, and avoid sending any more
> > events until management queries the filter status?
> >  
> 
> Or use rate-limiting, similar to what we have done for other
> guest-triggered events (such as BALLOON_CHANGE), where management can
> then tweak the maximum frequency at which it is willing to receive events.
> 
> -- 
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
> 

I'm not sure how would management set the rate though,
and any throttling here might hurt the guest,
unlike the balloon.

OTOH what I proposed kind of moderates itself automatically.

-- 
MST