- Update hn(4)'s stats properly for non-transparent mode VF.
- Allow BPF tapping to hn(4) for non-transparent mode VF.
- Don't setup mbuf hash, if 'options RSS' is set.
In Azure, when VF is activated, TCP SYN and SYN|ACK go through hn(4)
while the rest of segments and ACKs belonging to the same TCP 4-tuple
go through the VF. So don't setup mbuf hash, if a VF is activated
and 'options RSS' is not enabled. hn(4) and the VF may use neither
the same RSS hash key nor the same RSS hash function, so the hash
value for packets belonging to the same flow could be different!
- Disable LRO.
hn(4) will only receive broadcast packets, multicast packets, TCP
SYN and SYN|ACK (in Azure), LRO is useless for these packet types.
For non-transparent, we definitely _cannot_ enable LRO at all, since
the LRO flush will use hn(4) as the receiving interface; i.e.
hn_ifp->if_input(hn_ifp, m).
While I'm here, remove unapplied comment and minor style change.
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11978
a97fff1913