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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">While I was running OVS-DPDK with Geneve traffic I hit a problem where in the first flow OVS does not know which port to forward the packet to, so it sends it to all the ports on the bridge leading to the creation of this datapath rule:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif">skb_priority(0/0),tunnel(tun_id=0x5,src=101.11.7.1,dst=101.11.8.1,ttl=64/0,tp_src=43419/0,tp_dst=6081/0,flags(-df-csum+key)),skb_mark(0/0),ct_state(0/0),ct_zone(0/0),ct_mark(0/0),ct_label(0/0),recirc_id(0),dp_hash(0/0),in_port(genev_sys_6081),packet_type(ns=0,id=0),eth(src=e4:0b:07:08:00:03,dst=e4:0b:08:08:00:02),eth_type(0x0800),ipv4(src=11.11.7.2/0.0.0.0,dst=11.11.8.1,proto=6,tos=0/0,ttl=64/0,frag=no),tcp(src=19016/0,dst=19016/0),tcp_flags(0/0),
packets:208, bytes:23738, used:4.756s, flags:SFPR., dp:ovs, actions: enp8s0f0_0,ovs-sriov1,enp8s0f0_0, dp-extra-info:miniflow_bits(10,2)<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">after OVS learns the correct port to forward to it issues a flow modification that fails:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">2021-01-12T11:41:42.733Z|00001|dpif(revalidator13)<span style="color:black">|WARN|netdev@ovs-netdev: failed to put[modify] (No such file or
</span>directory) ufid:9844be55-8c6d-4ef0-9bb8-622b13aa0c7b skb_priority(0/0),tunnel(tun_id=0x5,src=101.11.8.1,dst=101.11.7.1,ttl=64/0,tp_src=50367/0,tp_dst=6081/0,flags(-df-csum+key)),skb_mark(0/0),ct_state(0/0),ct_zone(0/0),ct_mark(0/0),ct_label(0/0),recirc_id(0),dp_hash(0/0),in_port(3),packet_type(ns=0,id=0),eth(src=e4:0b:08:08:00:02,dst=e4:0b:07:08:00:03),eth_type(0x0800),ipv4(src=11.11.8.1/0.0.0.0,dst=11.11.7.2,proto=1,tos=0/0,ttl=64/0,frag=no),icmp(type=8/0,code=0/0),
actions:4<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This behavior was already discussed in [1] <o:p></o:p></p>
<p class="MsoNormal">There is a proposed fix the this discussion that was never applied, in the discussion they mention that the fix is not complete “(The following patch is not actually the real fix because the code should still look at the key if no ufid
was provided.)”<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So my questions are: <o:p></o:p></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">What are the risks of changing the procedure of searching for the flows moving to look for the flow using UFID and not netdev_key?<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">Why this fix was not applied or merged to the master branch?<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[1] <a href="https://lists.linuxfoundation.org/pipermail/ovs-dev/2018-September/352579.html">
https://lists.linuxfoundation.org/pipermail/ovs-dev/2018-September/352579.html</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Helvetica",sans-serif">Salem Sol<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Helvetica",sans-serif;color:gray">SW. Engineer – Mellanox Cloud Acceleration<br>
Mobile: +972 (74) 7238453</span><span style="font-size:10.0pt;font-family:"Helvetica",sans-serif"><br>
<span style="color:#70AD47"><a href="http://www.nvidia.com/" target="_blank"><span style="color:#70AD47">NVIDIA</span></a></span><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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