On Thu, May 16, 2013 at 06:03:26PM +0300, Michael S. Tsirkin wrote: > 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.
To clarify the issue: - guest might be changing macs a lot not because it is malicious, but because it has a reason to do it. delaying the filter update for such a guest would drop lots of packets. To clarify what I am proposing: - on info mac-table -> clear flag - on mac-table change -> test and set flag if was not set -> send event to management if was set -> do not send event This way management does not get events faster than it can handle them. > -- > MST