On Mon, 10 Aug 2009 16:32:01 +0000 "Fischer, Anna" <anna.fisc...@hp.com> wrote:
> > Subject: Re: [evb] RE: [PATCH][RFC] net/bridge: add basic VEPA support > > > > On Monday 10 August 2009, Stephen Hemminger wrote: > > > On Sun, 09 Aug 2009 14:19:08 +0300, Or Gerlitz > > <ogerl...@voltaire.com> wrote: > > > > Looking in macvlan_set_multicast_list() it acts in a similar manner > > to > > > > macvlan_set_mac_address() in the sense that it calls dev_mc_sync(). > > I > > > > assume what's left is to add macvlan_hash_xxx multicast logic to > > > > map/unmap multicast groups to what macvlan devices want to receive > > them > > > > and this way the flooding can be removed, correct? > > > > > > The device can just flood all multicast packets, since the filtering > > > is done on the receive path anyway. > > Is this handled by one of the additional patches? In the current kernel tree > macvlan code it looks as if multicast filtering is only handled by the > physical device driver, but not on particular macvlan devices. > > > > But we'd still have to copy the frames to user space (for both > > macvtap and raw packet sockets) and exit from the guest to inject > > it into its stack, right? > > I think it would be nice if you can implement what Or describes for > macvlan and avoid flooding, and it doesn't sound too hard to do. > > I guess one advantage for macvlan (over the bridge) is that you can > program in all information you have for the ports attached to it, e.g. > MAC addresses and multicast addresses. So you could take advantage of > that whereas the bridge always floods multicast frames to all ports. > > How would this work though, if the OS inside the guest wants to register > to a particular multicast address? Is this propagated through the backend > drivers to the macvlan/macvtap interface? Sure filtering is better, but multicast performance with large number of guests is really a corner case, not the real performance issue. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/virtualization
