if_ixv: disable RSS configuration on 82599 and X540 VFs

[avg]

Summary

It is reported that those VFs share their RSS configuration with PF and,
thus, they cannot be configured independently.

Also:

• add missing opt_rss.h to if_ixv.c, otherwise RSS kernel option could not be seen
• do not enable IXGBE_FEATURE_RSS on the older VFs
• set flowid / hash type to M_HASHTYPE_NONE or M_HASHTYPE_OPAQUE_HASH (based on what the hardware reports) if IXGBE_FEATURE_RSS is not set

Sponsored by: Panzura

[avg]

sys/dev/ixgbe/ix_txrx.c

549 ↗

(On Diff #62267)

By the way, should this be M_HASHTYPE_OPAQUE or M_HASHTYPE_OPAQUE_HASH ?

[avg]

sys/dev/ixgbe/ix_txrx.c

549 ↗

(On Diff #62267)

I think that sephe once did M_HASHTYPE_OPAQUE ==> M_HASHTYPE_OPAQUE_HASH (rS301538), but that got reverted during the convertion to iflib in rS327031.

[avg]

Any feedback at all?

[avg]

So, no hard feelings if I commit this?
I will try to handle any fallout if it happens.

[jeb]

sys/dev/ixgbe/if_ixv.c

1462 ↗

(On Diff #62267)

Why wouldn't the guard be feat_en & ICE_FEATURE_RSS?

[jacob.e.keller_intel.com]

sys/dev/ixgbe/if_ixv.c

1462 ↗

(On Diff #62267)

Doex ixgbe have feature flags for this? (seeing as this isn't the ice driver).

[jeb]

sys/dev/ixgbe/if_ixv.c

1462 ↗

(On Diff #62267)

Sorry, not ICE, but rather IXGBE_FEATURE_RSS.

[avg]

sys/dev/ixgbe/if_ixv.c

1462 ↗

(On Diff #62267)

IXGBE_FEATURE_RSS is defined to zero if RSS is not enabled in the kernel configuration, see ixgbe_features.h.
So, in that case ixv_initialize_rss_mapping() would not be called at all if I used feat_cap & IXGBE_FEATURE_RSS check.
But I think that we still want to call ixv_initialize_rss_mapping() to setup the "hardware RSS" -- the interrupt / packet distribution -- even if the "software RSS" is not enabled in the network stack.