3 files changed, 55 insertions, 7 deletions
diff --git a/doc/guides/nics/ena.rst b/doc/guides/nics/ena.rst
index 073b35ae..9062d7bf 100644
--- a/doc/guides/nics/ena.rst
+++ b/doc/guides/nics/ena.rst
@@ -187,11 +187,20 @@ Prerequisites
 -------------
 
 #. Prepare the system as recommended by DPDK suite.  This includes environment
-   variables, hugepages configuration, tool-chains and configuration
+   variables, hugepages configuration, tool-chains and configuration.
 
-#. Insert igb_uio kernel module using the command 'modprobe igb_uio'
+#. ENA PMD can operate with ``vfio-pci`` or ``igb_uio`` driver.
 
-#. Bind the intended ENA device to igb_uio module
+#. Insert ``vfio-pci`` or ``igb_uio`` kernel module using the command
+   ``modprobe vfio-pci`` or ``modprobe igb_uio`` respectively.
+
+#. For ``vfio-pci`` users only:
+   Please make sure that ``IOMMU`` is enabled in your system,
+   or use ``vfio`` driver in ``noiommu`` mode::
+
+     echo 1 > /sys/module/vfio/parameters/enable_unsafe_noiommu_mode
+
+#. Bind the intended ENA device to ``vfio-pci`` or ``igb_uio`` module.
 
 
 At this point the system should be ready to run DPDK applications. Once the
diff --git a/doc/guides/nics/enic.rst b/doc/guides/nics/enic.rst
index c535b589..7738829e 100644
--- a/doc/guides/nics/enic.rst
+++ b/doc/guides/nics/enic.rst
@@ -39,7 +39,7 @@ How to obtain ENIC PMD integrated DPDK
 --------------------------------------
 
 ENIC PMD support is integrated into the DPDK suite. dpdk-<version>.tar.gz
-should be downloaded from http://dpdk.org
+should be downloaded from http://core.dpdk.org/download/
 
 
 Configuration information
@@ -140,6 +140,35 @@ Masking of these feilds for partial match is also supported.
 Without advanced filter support, the flow director is limited to IPv4
 perfect filtering of the 5-tuple with no masking of fields supported.
 
+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.
+
 Limitations
 -----------
 
@@ -153,9 +182,10 @@ 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
-  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
 
@@ -163,6 +193,14 @@ Limitations
      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`.
 
diff --git a/doc/guides/nics/features/ena.ini b/doc/guides/nics/features/ena.ini
index 74969fd0..d607fcc3 100644
--- a/doc/guides/nics/features/ena.ini
+++ b/doc/guides/nics/features/ena.ini
@@ -22,5 +22,6 @@ Inner L4 checksum    = Y
 Basic stats          = Y
 Extended stats       = Y
 Linux UIO            = Y
+Linux VFIO           = Y
 x86-32               = Y
 x86-64               = Y