New upstream version 17.11.4

[deb_dpdk.git] / doc / guides / nics / enic.rst

diff --git a/doc/guides/nics/enic.rst b/doc/guides/nics/enic.rst
index cb5ae12..a11627a 100644 (file)
--- a/doc/guides/nics/enic.rst
+++ b/doc/guides/nics/enic.rst
@@ -252,6 +252,35 @@ Generic Flow API is supported. The baseline support is:
 More features may be added in future firmware and new versions of the VIC.
 Please refer to the release notes.
 
 More features may be added in future firmware and new versions of the VIC.
 Please refer to the release notes.
 

+Ingress VLAN Rewrite
+--------------------
+
+VIC adapters can tag, untag, or modify the VLAN headers of ingress
+packets. The ingress VLAN rewrite mode controls this behavior. By
+default, it is set to pass-through, where the NIC does not modify the
+VLAN header in any way so that the application can see the original
+header. This mode is sufficient for many applications, but may not be
+suitable for others. Such applications may change the mode by setting
+``devargs`` parameter ``ig-vlan-rewrite`` to one of the following.
+
+- ``pass``: Pass-through mode. The NIC does not modify the VLAN
+  header. This is the default mode.
+
+- ``priority``: Priority-tag default VLAN mode. If the ingress packet
+  is tagged with the default VLAN, the NIC replaces its VLAN header
+  with the priority tag (VLAN ID 0).
+
+- ``trunk``: Default trunk mode. The NIC tags untagged ingress packets
+  with the default VLAN. Tagged ingress packets are not modified. To
+  the application, every packet appears as tagged.
+
+- ``untag``: Untag default VLAN mode. If the ingress packet is tagged
+  with the default VLAN, the NIC removes or untags its VLAN header so
+  that the application sees an untagged packet. As a result, the
+  default VLAN becomes `untagged`. This mode can be useful for
+  applications such as OVS-DPDK performance benchmarks that utilize
+  only the default VLAN and want to see only untagged packets.
+

 .. _enic_limitations:
 
 Limitations
 .. _enic_limitations:
 
 Limitations


@@ -267,9 +296,10 @@ Limitations
   In test setups where an Ethernet port of a Cisco adapter in TRUNK mode is
   connected point-to-point to another adapter port or connected though a router
   instead of a switch, all ingress packets will be VLAN tagged. Programs such
   In test setups where an Ethernet port of a Cisco adapter in TRUNK mode is
   connected point-to-point to another adapter port or connected though a router
   instead of a switch, all ingress packets will be VLAN tagged. Programs such

-  as l3fwd which do not account for VLAN tags in packets will misbehave. The
-  solution is to enable VLAN stripping on ingress. The follow code fragment is
-  example of how to accomplish this:
+  as l3fwd may not account for VLAN tags in packets and may misbehave. One
+  solution is to enable VLAN stripping on ingress so the VLAN tag is removed
+  from the packet and put into the mbuf->vlan_tci field. Here is an example
+  of how to accomplish this:

 
 .. code-block:: console
 
 
 .. code-block:: console
 


@@ -277,6 +307,14 @@ Limitations
      vlan_offload |= ETH_VLAN_STRIP_OFFLOAD;
      rte_eth_dev_set_vlan_offload(port, vlan_offload);
 
      vlan_offload |= ETH_VLAN_STRIP_OFFLOAD;
      rte_eth_dev_set_vlan_offload(port, vlan_offload);
 

+Another alternative is modify the adapter's ingress VLAN rewrite mode so that
+packets with the default VLAN tag are stripped by the adapter and presented to
+DPDK as untagged packets. In this case mbuf->vlan_tci and the PKT_RX_VLAN and
+PKT_RX_VLAN_STRIPPED mbuf flags would not be set. This mode is enabled with the
+``devargs`` parameter ``ig-vlan-rewrite=untag``. For example::
+
+    -w 12:00.0,ig-vlan-rewrite=untag
+

 - Limited flow director support on 1200 series and 1300 series Cisco VIC
   adapters with old firmware. Please see :ref:`enic-flow-director`.
 
 - Limited flow director support on 1200 series and 1300 series Cisco VIC
   adapters with old firmware. Please see :ref:`enic-flow-director`.