Hi Jyotsna, Just to confirm --- are you running VPP + DPDK IAVF, or VPP + the AVF plugin with the quick workaround? I’m asking because the patch is only applicable to VPP + DPDK IAVF. If you are using that setup, could you please share your startup.conf and the VPP CLI commands you used to configure VPP? That will help me look into the issue in more detail.
Cheers, Jay Wang From: [email protected] <[email protected]> On Behalf Of Jyotsna Dhumale via lists.fd.io Sent: Tuesday, November 25, 2025 10:21 AM To: [email protected] Cc: [email protected]; Paul Szczepanek <[email protected]>; Vinod Krishna <[email protected]>; Dhruv Tripathi <[email protected]>; Wathsala Vithanage <[email protected]> Subject: Re: [vpp-dev] [VPP 25.02 | ARM64 | E810-C | IAVF] Packets showing length 65535 in DPDK input node (works fine on VPP 22.02) Hi Jay Wang, Thanks a lot for the patch. Even I am facing the same problem[pkt_len 65535] with VPP25.02 and ARM64 Board : Ampere(R) Altra(R) Processor Q64-30 CPU @ 3.0GHz NIC : E810-C 4 ports I tested with the patch you provided, but I am still running into same problem of pkt_len coming as 65535. Attached the build log for your reference, which shows patch is applied correctly and build is successful. Later VPP is built using the new vpp-ext-dep package generated with the patch. Anything that I am missing or missing in the patch? Let me know if you need any other information from my side. Thanks and regards, Jyotsna On Thu, Nov 20, 2025 at 3:15 AM Jay Wang via lists.fd.io<http://lists.fd.io> <[email protected]<mailto:[email protected]>> wrote: Hi Nousi, I can confirm that I was able to reproduce your issue in my local test environment(Ampere Altra Max 96 Cores with the Intel E810-C 2x ports NIC). The issue also persists in the latest VPP codebase, so I spent some time investigating it. From what I observed, commit[1] appears to be the root cause. This commit introduces NEON intrinsics to add support for the IAVF Rx vector path on Arm platforms in DPDK. I don’t want to bother you with the implementation details of the Rx vector function[2]. But in short, the issue occurs because the function writes the pkt_len field to the wrong location in the rte_mbuf when copying from the hardware descriptor. I’ve created a quick workaround for VPP 25.02(see attached patch) and tested it with 64B/1024B packets. It seems to work fine. Please give it a try and let me know if it resolves the issue on your side. VPP 25.02 works fine on X86 systems because it uses a different Rx vector code path. Interestingly, I observed a similar packet length issue when testing the X86 counterpart of Rx vector code path[3]. Thanks, Jay Wang [1] https://gerrit.fd.io/r/c/vpp/+/37017 [2] https://github.com/DPDK/dpdk/blob/main/drivers/net/intel/iavf/iavf_rxtx_vec_neon.c#L144 [3] https://github.com/DPDK/dpdk/blob/main/drivers/net/intel/iavf/iavf_rxtx_vec_sse.c#L391 From: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> On Behalf Of nousi via lists.fd.io<http://lists.fd.io> Sent: Tuesday, November 11, 2025 2:22 PM To: [email protected]<mailto:[email protected]> Subject: [vpp-dev] [VPP 25.02 | ARM64 | E810-C | IAVF] Packets showing length 65535 in DPDK input node (works fine on VPP 22.02) Hi everyone, I’m seeing a packet length issue after upgrading to VPP 25.02 on ARM64 (Ampere® Altra® Q64-30 @ 3.0GHz) with an Intel E810-C (4x ports) NIC using the IAVF driver. All packets received in the dpdk-input node show a length of 65535 bytes, which is clearly incorrect. This is visible in both trace and pcap captures. Here’s what I’ve observed so far: * The issue only appears with VPP 25.02 on ARM64. * The same platform (hardware + NIC) works perfectly with VPP 22.02 — packet lengths are reported correctly. * On X86 systems, VPP 25.02 also works fine (no packet length issue). * So it seems specific to VPP 25.02 + ARM64 + IAVF driver combination. Setup details: * CPU: Ampere® Altra® Q64-30 (ARM64) * NIC: Intel E810-C (4 ports) * Driver: IAVF (DPDK) * VPP version: 25.02 * Symptom: All packets show length = 65535 in dpdk-input node Has anyone else seen this behavior or is aware of any related changes in VPP 25.02 or the IAVF/DPDK layer for ARM64? Would appreciate any pointers, patches, or debug hints — especially if someone has tested E810/IAVF on ARM with newer VPP versions. Thanks a lot in advance! Nousi. IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
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