VFs by default are able to see all tagged traffic regardless of trust
and VLAN filters configured.

Add new private flag vf-vlan-pruning that allows changing of default
VF behavior for tagged traffic. When the flag is turned on
untrusted VF will only be able to receive untagged traffic
or traffic with VLAN tags it has created interfaces for

The flag is off by default and can only be changed if
there are no VFs spawned on the PF. This flag will only be effective
when no PVID is set on VF and VF is not trusted.
Add new function that computes the correct VLAN ID for VF VLAN filters
based on trust, PVID, vf-vlan-prune-disable flag and current VLAN ID.

Testing Hints:

Test 1: vf-vlan-pruning == off
==============================
1. Set the private flag
> ethtool --set-priv-flag eth0 vf-vlan-pruning off (default setting)
2. Use scapy to send any VLAN tagged traffic and make sure the VF
receives all VLAN tagged traffic that matches its destination MAC
filters (unicast, multicast, and broadcast).

Test 2: vf-vlan-pruning == on
==============================
1. Set the private flag
> ethtool --set-priv-flag eth0 vf-vlan-pruning on
2. Use scapy to send any VLAN tagged traffic and make sure the VF does
not receive any VLAN tagged traffic that matches its destination MAC
filters (unicast, multicast, and broadcast).
3. Add a VLAN filter on the VF netdev
> ip link add link eth0v0 name vlan10 type vlan id 10
4. Bring the VLAN netdev up
> ip link set vlan10 up
4. Use scapy to send traffic with VLAN 10, VLAN 11 (anything not VLAN
10), and untagged traffic. Make sure the VF only receives VLAN 10
and untagged traffic when the link partner is sending.

Test 3: vf-vlan-pruning == off && VF is in a port VLAN
==============================
1. Set the private flag
> ethtool --set-priv-flag eth0 vf-vlan-pruning off (default setting)
2. Create a VF
> echo 1 > sriov_numvfs
3. Put the VF in a port VLAN
> ip link set eth0 vf 0 vlan 10
4. Use scapy to send traffic with VLAN 10 and VLAN 11 (anything not VLAN
10) and make sure the VF only receives untagged traffic when the link
partner is sending VLAN 10 tagged traffic as the VLAN tag is expected
to be stripped by HW for port VLANs and not visible to the VF.

Test 4: Change vf-vlan-pruning while VFs are created
==============================
echo 0 > sriov_numvfs
ethtool --set-priv-flag eth0 vf-vlan-pruning off
echo 1 > sriov_numvfs
ethtool --set-priv-flag eth0 vf-vlan-pruning on (expect failure)
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>