Currently it is possible to create a filter which breaks TX traffic, e.g.:

tc filter add dev $PF1 ingress protocol ip prio 1 flower ip_proto udp
dst_port $PORT action mirred egress redirect dev $VF1_PR

This adds a rule which might match both TX and RX traffic, and in TX path
the PF will actually receive the traffic, which breaks communication.

To fix this, add a match on direction metadata flag when adding a tc rule.

Because of the way metadata is currently handled, a duplicate lookup word
would appear if VLAN metadata is also added. The lookup would still work
correctly, but one word would be wasted. To prevent it, lookup 0 now always
contains all metadata. When any metadata needs to be added, it is added to
lookup 0 and lookup count is not incremented. This way, two flags residing
in the same word will take up one word, instead of two.

Note: the drop action is also affected, i.e. it will now only work in one
direction.
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>