Re: [Qemu-devel] [PATCH v6] net: add support of mac-programming over macvtap in QEMU side

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 17 Jun 2013 18:10:23 +0300
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Mon, Jun 17, 2013 at 10:54:39AM -0400, Luiz Capitulino wrote:
> > On Mon, 17 Jun 2013 17:42:50 +0300
> > "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > 
> > > > The 1000ms I talked about is *not* what the guest will see. If there are
> > > > events pending, the throttle API just queues the event and returns right
> > > > away. I'd even _guess_ that this is faster then emitting the event.
> > > 
> > > If the filter is not updated for 1000ms then that is guest visible:
> > > it is not getting packets with the new MAC.
> > 
> > Let me understand this better: the filter is going to be updated by
> > libvirt, is that correctly?
> 
> Exactly.
> 
> > If this is right, then I can understand where you came from, but how
> > can we possibly control how long it will take for libvirt to take
> > action?
> 
> We can't, it's a best effort, but that's also true for some NICs.
> At least let's not introduce an artificial delay there.

Got it. Okay, I think the flag is fine and won't ask for more evidence then.

Although I still wonder if we would do alright w/o the flag and w/o using
the throttle API...