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<p>Hi,</p>
<p>I'm trying to use the memif PMD with Jumbo Frames, without any
success yet.<br>
Please note that I'm currently using DPDK 21.11, but could
consider updating.<br>
</p>
<p><br>
</p>
<p>On standard packet size, I'm able to transmit packets using memif
with the following commands:</p>
<p>Terminal 1 (receiver, launch first):<br>
# ./dpdk-testpmd -l 2-3 --vdev=net_memif0,id=0,role=server
--file-prefix=pmd1 -- --forward-mode=rxonly --max-pkt-len=1518</p>
<p>Terminal 2 (sender, launch second):<br>
# ./dpdk-testpmd -l 0-1 --vdev=net_memif0,id=0,role=client
--file-prefix=pmd2 -- --forward-mode=txonly --max-pkt-len=1518</p>
<p><br>
</p>
<p>When trying to send Jumbo Frames, I get an error on the server
launch: <br>
</p>
<p>
# ./dpdk-testpmd -l 2-3 --vdev=net_memif0,id=0,role=server
--file-prefix=pmd1 -- --forward-mode=rxonly --max-pkt-len=9000<br>
...<br>
Frame size (9000) > device max frame size (1518) for port_id 0<br>
...<br>
</p>
<p><br>
</p>
<p>Do you know if it is possible to increase this device max frame
size for the memif PMD ?</p>
<p><br>
</p>
<p>About what I tried:</p>
<p>- Changing the bsize (Size of single packet buffer) option of the
PMD to a value higher than 9000 (I tried 9000 and 2^14=16384).<br>
I did not understand what this parameter changes, but it did not
seem to help, the error stayed the same.</p>
<p>- Reading the doc (both <a moz-do-not-send="true"
href="https://doc.dpdk.org/guides/nics/memif.html">DPDK</a>'s
and <a moz-do-not-send="true"
href="https://docs.fd.io/vpp/17.10/libmemif_doc.html">VPP</a>'s),
searching for MTU limitations, but saw no such thing.</p>
<p>- Start from the error message to find where the device max frame
size is set. It is initialized at
drivers/net/memif/rte_eth_memif.c:198,<br>
to the value RTE_ETHER_MAX_LEN (1518), and left untouched after
that. Is there any reason to limit the PMD to this value, or we
could<br>
add a setter for this value ?<br>
</p>
<p><br>
</p>
<p>Thanks for any help on this issue,<br>
Julien<br>
</p>
<p><br>
</p>
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