remove blank lines at end of file

[dpdk.git] / doc / guides / nics / tap.rst

diff --git a/doc/guides/nics/tap.rst b/doc/guides/nics/tap.rst
index ea61be3..85c7b89 100644 (file)
--- a/doc/guides/nics/tap.rst
+++ b/doc/guides/nics/tap.rst
@@ -1,8 +1,8 @@
 ..  SPDX-License-Identifier: BSD-3-Clause
     Copyright(c) 2016 Intel Corporation.
 
-Tap Poll Mode Driver
-====================
+Tun|Tap Poll Mode Driver
+========================
 
 The ``rte_eth_tap.c`` PMD creates a device using TAP interfaces on the
 local host. The PMD allows for DPDK and the host to communicate using a raw
@@ -37,6 +37,12 @@ for each interface string containing ``mac=fixed``. The MAC address is formatted
 as 00:'d':'t':'a':'p':[00-FF]. Convert the characters to hex and you get the
 actual MAC address: ``00:64:74:61:70:[00-FF]``.
 
+   --vdev=net_tap0,mac="00:64:74:61:70:11"
+
+The MAC address will have a user value passed as string. The MAC address is in
+format with delimiter ``:``. The string is byte converted to hex and you get
+the actual MAC address: ``00:64:74:61:70:11``.
+
 It is possible to specify a remote netdevice to capture packets from by adding
 ``remote=foo1``, for example::
 
@@ -77,6 +83,17 @@ can utilize that stack to handle the network protocols. Plus you would be able
 to address the interface using an IP address assigned to the internal
 interface.
 
+The TUN PMD allows user to create a TUN device on host. The PMD allows user
+to transmit and receive packets via DPDK API calls with L3 header and payload.
+The devices in host can be accessed via ``ifconfig`` or ``ip`` command. TUN
+interfaces are passed to DPDK ``rte_eal_init`` arguments as ``--vdev=net_tunX``,
+where X stands for unique id, example::
+
+   --vdev=net_tun0 --vdev=net_tun1,iface=foo1, ...
+
+Unlike TAP PMD, TUN PMD does not support user arguments as ``MAC`` or ``remote`` user
+options. Default interface name is ``dtunX``, where X stands for unique id.
+
 Flow API support
 ----------------
 
@@ -91,7 +108,7 @@ The kernel support can be checked with this command::
 Supported items:
 
 - eth: src and dst (with variable masks), and eth_type (0xffff mask).
-- vlan: vid, pcp, tpid, but not eid. (requires kernel 4.9)
+- vlan: vid, pcp, but not eid. (requires kernel 4.9)
 - ipv4/6: src and dst (with variable masks), and ip_proto (0xffff mask).
 - udp/tcp: src and dst port (0xffff) mask.
 
@@ -135,6 +152,22 @@ Distribute IPv4 TCP packets using RSS to a given MAC address over queues 0-3::
    testpmd> flow create 0 priority 4 ingress pattern eth dst is 0a:0b:0c:0d:0e:0f \
             / ipv4 / tcp / end actions rss queues 0 1 2 3 end / end
 
+Multi-process sharing
+---------------------
+
+It is possible to attach an existing TAP device in a secondary process,
+by declaring it as a vdev with the same name as in the primary process,
+and without any parameter.
+
+The port attached in a secondary process will give access to the
+statistics and the queues.
+Therefore it can be used for monitoring or Rx/Tx processing.
+
+The IPC synchronization of Rx/Tx queues is currently limited:
+
+  - Maximum 8 queues shared
+  - Synchronized on probing, but not on later port update
+
 Example
 -------
 
@@ -148,8 +181,8 @@ used to build the dpdk you pulled down.
 Run pktgen from the pktgen directory in a terminal with a commandline like the
 following::
 
-    sudo ./app/app/x86_64-native-linuxapp-gcc/app/pktgen -l 1-5 -n 4        \
-     --proc-type auto --log-level 8 --socket-mem 512,512 --file-prefix pg   \
+    sudo ./app/app/x86_64-native-linux-gcc/app/pktgen -l 1-5 -n 4        \
+     --proc-type auto --log-level debug --socket-mem 512,512 --file-prefix pg   \
      --vdev=net_tap0 --vdev=net_tap1 -b 05:00.0 -b 05:00.1                  \
      -b 04:00.0 -b 04:00.1 -b 04:00.2 -b 04:00.3                            \
      -b 81:00.0 -b 81:00.1 -b 81:00.2 -b 81:00.3                            \
@@ -241,6 +274,11 @@ Please refer to ``iproute2`` package file ``lib/bpf.c`` function
 An example utility for eBPF instruction generation in the format of C arrays will
 be added in next releases
 
+TAP reports on supported RSS functions as part of dev_infos_get callback:
+``ETH_RSS_IP``, ``ETH_RSS_UDP`` and ``ETH_RSS_TCP``.
+**Known limitation:** TAP supports all of the above hash functions together
+and not in partial combinations.
+
 Systems supporting flow API
 ---------------------------
 
@@ -260,4 +298,3 @@ Systems supporting flow API
 | Azure Ubuntu 16.04,| No limitation         |
 | kernel 4.13        |                       |
 +--------------------+-----------------------+
-