xref: /dpdk/doc/guides/nics/null.rst (revision b583b9a1bb49e86aa0937d55415713282000c536)
162a667f3SFerruh Yigit..  SPDX-License-Identifier: BSD-3-Clause
262a667f3SFerruh Yigit    Copyright(c) 2020 Intel Corporation.
362a667f3SFerruh Yigit
462a667f3SFerruh YigitNULL Poll Mode Driver
562a667f3SFerruh Yigit=====================
662a667f3SFerruh Yigit
762a667f3SFerruh YigitNULL PMD is a simple virtual driver mainly for testing. It always returns success for all packets for Rx/Tx.
862a667f3SFerruh Yigit
962a667f3SFerruh YigitOn Rx it returns requested number of empty packets (all zero). On Tx it just frees all sent packets.
1062a667f3SFerruh Yigit
1162a667f3SFerruh Yigit
1262a667f3SFerruh YigitUsage
1362a667f3SFerruh Yigit-----
1462a667f3SFerruh Yigit
1562a667f3SFerruh Yigit.. code-block:: console
1662a667f3SFerruh Yigit
1768d99d00SCiara Power   ./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 --vdev net_null0 --vdev net_null1 -- -i
1862a667f3SFerruh Yigit
1962a667f3SFerruh Yigit
20*b583b9a1SFerruh YigitRuntime Configuration
21*b583b9a1SFerruh Yigit---------------------
2262a667f3SFerruh Yigit
2362a667f3SFerruh Yigit- ``copy`` [optional, default disabled]
2462a667f3SFerruh Yigit
2562a667f3SFerruh Yigit It copies data of the packet before Rx/Tx. For Rx it uses another empty dummy mbuf for this.
2662a667f3SFerruh Yigit
2762a667f3SFerruh Yigit.. code-block:: console
2862a667f3SFerruh Yigit
2968d99d00SCiara Power   ./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 --vdev "net_null0,copy=1" -- -i
3062a667f3SFerruh Yigit
3162a667f3SFerruh Yigit- ``size`` [optional, default=64 bytes]
3262a667f3SFerruh Yigit
3362a667f3SFerruh Yigit Custom packet length value to use.r
3462a667f3SFerruh Yigit If ``copy`` is enabled, this is the length of copy operation.
3562a667f3SFerruh Yigit
3662a667f3SFerruh Yigit.. code-block:: console
3762a667f3SFerruh Yigit
3868d99d00SCiara Power   ./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 --vdev "net_null0,size=256" -- -i
3962a667f3SFerruh Yigit
40f51ecf2fSFerruh Yigit- ``no-rx`` [optional, default disabled]
41f51ecf2fSFerruh Yigit
42f51ecf2fSFerruh Yigit Makes PMD more like ``/dev/null``. On Rx no packets received, on Tx all packets are freed.
43f51ecf2fSFerruh Yigit This option can't co-exist with ``copy`` option.
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