Adding Flow Director sysctls to ixgbe(4)

[Ben Hutchings]

On Thu, 2011-09-08 at 18:28 +0200, K. Macy wrote:
> > Whatever the mechanism is, the interface should allow for:
> >
> > - Flexible matching on layer 2, 3 and 4 header fields
> > - Masking out some bits before matching (e.g. ignoring priority bits of
> >  VLAN tag or least significant bits of IPv4 address)
> > - Priority of rules in case several match a single flow.  This may
> >  need to be combined with location, since in a TCAM location may
> >  determine priority.
> > - Requesting packets to be dropped, steered to a single RX queue, or
> >  steered to a range of RX queues (using a flow hash and indirection
> >  table)
> > - Use of multiple hash indirection tables
> 
> Do you feel that the Linux API for this is the right place to start
> looking?

You can certainly learn from the mistakes made in Linux. :-)

> Earlier you said: "The exact capabilities of the hardware
> are all quite
> different and we're still recovering from the early mistake of
> defining two subtly different interfaces." Have the two APIs been
> unified, if not which one do you believe is the "right" one?

RX NFC is the right one.  The other one (RX n-tuple) will be removed
once I've converted the sfc driver to use RX NFC.

It isn't flexible enough to cover the full matching capabilities and it
doesn't allow for requesting steering + hashing, although I'm hoping to
extend it to cover that later.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.