Are ./valte-ctl and ./bridge friends or competitors?

[Vincenzo Maffione]

2017-03-20 10:51 GMT+01:00 Harry Schmalzbauer <freebsd at omnilan.de>:

> Bezüglich Vincenzo Maffione's Nachricht vom 18.03.2017 09:29 (localtime):
> >…
> >>> Actually, there is pending work on bhyve and netmap, that is going to
> be
> >>> merged soon, available at https://github.com/vmaffione/freebsd/ in
> >>> branch ptnet-head.
> >>>
> >>> If you are interested, here there is some information
> >>> https://wiki.freebsd.org/DevSummit/201609?action=
> >> AttachFile&do=view&target=20160923-freebsd-summit-ptnet.pdf
> >>> <https://wiki.freebsd.org/DevSummit/201609?action=
> >> AttachFile&do=view&target=20160923-freebsd-summit-ptnet.pdf>
> >>> together with bhyve cmdlines.
>
> Congratulations, nice work and presentation :-)
>

Thanks!

>
> …
> >> So I'm a bit lost regarding furhter decisions. My prefered if_lagg(4)
> >> setup doesn't work with netmap at the moment, if_bridge(4) has
> >> in-house-overhead and forces me to either drop jumbo frames completely
> >> or use 9k MTU for any bridge member.
> >> Will look into openvSwitch. Or better get some card providing VFs?
> >> Or wait the ptnet merge and check if I can deploy my desired setup then?
> >> And, I want to keep TSO and HWVLAN_TAG on the host interfaces…
> >>
> >>
> > It depends on your requirements, in terms of connectivity between VMs and
> > NICs and required performance (for a given workload, e.g. average
> > packet-size, average packet rate, etc.).
> > If you really want TSO an other offloadings on the phyisical NIC, then
> you
> > cannot use that NIC in netmap mode (e.g. attaching it to VALE).
>
> So to summarize for newbies exploring netmap(4) world in combination
> with physical uplinks and virtual interfaces, it's important to do the
> following uplink NIC configuration (ifconfig(8)):
> -rxcsum -txcsum -rxcsum6 -txcsum6 -tso -lro promisc
>

Exactly. This is mentioned at the very end of netmap(4):

"netmap does not use features such as checksum offloading, TCP segmentation
offloading, encryption, VLAN encapsulation/decapsulation, etc.  When using
netmap to exchange packets with the host stack, make sure to disable these
features."

But it is probably a good idea to add these example ifconfig instructions
somewhere (man page or at least the README in the netmap repo).


>
> I guess vlanhwtag, vlanhwfilter and vlanhwtso don't interfere, do they?
>

Well, I think they interfere: if you receive a tagged packet and the NIC
strips the tag and puts it in the packet descriptor, then with netmap you
will see the untagged packet, and you wouldn't have a way to see the tag.

Cheers,

  Vincenzo


>
> Thanks,
>
> -harry
>



-- 
Vincenzo Maffione