WARNING - DO NOT test: IPv6 offload support in HEAD + patch for stable/9

Bjoern A. Zeeb bz at FreeBSD.org
Sat May 26 14:01:52 UTC 2012

On 25. May 2012, at 16:55 , Bjoern A. Zeeb wrote:

> Hey,
> last night I pushed in the essential offloading support changes for IPv6
> along with quite a bit of other "noise" into HEAD.  There is more locking
> improvements etc. to come once I have looped things back to my working tree
> and Michael Tuexen will improve SCTP/v6 on loopback as well soonish.
> This is a call for testing.  The in-tree cxgb(4) and ixgbe(4) drivers

WARNING - please refrain from testing IPv6 or updating your HEAD if you do
not have any of the above two NICs and rely on IPv6, or if you have updated and
are experiencing problems.  Disabling -txcsum -tso for the moment should be an
often unhelpful workaround.  It seems I was just lucky with my choice of other
NICs I tested but I cannot say which once are affected in the tree and which
once aren't.

Andrew Gallatin has pointed out that I missed an essential IPv4 header parsing
thing beyond TSO in some (most?) NIC drivers and it went unnoticed in review.
I'll post an update in a few hours once I know how many drivers are affected,
or have the proper fix as it might also be a question in which (old/cheap) silicon
might not do what is expected.

> have been updated to make use of the new features (TSO6/LRO6), and more
> drivers will follow (I already have cxgbe done, talking about mxge, ..)
> but others  should also see improvements for at least upper layer protocol
> checksum calculations and I'd love people to test with as many drivers as
> possible, as I plan to merge it for the upcoming 9.1-RELEASE cycle and
> wouldn't want to ship broken IPv6 in a few months;-)
> Here's the patch that should just apply to stable/9 matching what I put into
> HEAD (+ an earlier cxgb change) (untested):
> http://people.freebsd.org/~bz/20120525-01-ipv6-offload-mfc9.diff
> If you need a patch for a specific release please drop me a private email
> and I'll try to publish one (8.2 and up only though most likely).
> Please test and report to me or net at .
> Thanks
> /bz
> PS: we now also disallow LRO automatically if forwarding is turned on, just
> in case you wonder; a change that should have been done years ago;-)

Bjoern A. Zeeb                                 You have to have visions!
   It does not matter how good you are. It matters what good you do!

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