Native XDP on Intel X710

[eugenevt]

Cannot get it working, Ubuntu 22.04, kernel 6.5.0-35. I use maint-24.06 branch. I see that IGMP join is done, data flowing to the card, but nothing received. In MtlManager output I see following

libbpf: elf: skipping unrecognized data section(7) .xdp_run_config 
libbpf: elf: skipping unrecognized data section(7) xdp_metadata
libbpf: elf: skipping unrecognized data section(7) xdp_metadata

and following

[2024-06-04 18:00:54] [INFO] [Interface 3] Successfully inserted flow rule 7679 with queue 1
[2024-06-04 18:00:54] [ERROR] [Interface 3] Failed to update udp4_dp_filter map, dst_port: 16388

What I am missing?

[frankdjx]

For XDP, E810 is the one we only tested...

@ricmli Any input here?

[eugenevt]

The same on E810. Looks like my setup is not correct but I do not know what is wrong...

[frankdjx]

Not know why the ebpf filer map update is fail.

Failed to update udp4_dp_filter map, dst_port: 16388

A quick hack is allow all udp packet to XDP socket.

Change this line: https://github.com/OpenVisualCloud/Media-Transport-Library/blob/main/manager/mtl.xdp.c#L60 to

if (lookup_udp4_dp(dst_port) == 0) return XDP_DROP;

[eugenevt]

Recompiled MTL with gcc (was clang 14), now I have no error, but still no data. MTL kernel on the same interface works fine.

[eugenevt]

After recompiling xdp-tools using GCC, I was able to get the data on the X710 board, do not know what is wrong with my E810-QDA2 card, but installed in the same PC same slot it does not allow me do SRIOV, so maybe it is somehow affects XDP as well. So using GCC is critical, needs to be pointed in the documentation.

[frankdjx]

We are using GCC most time, not understand there's any special reason to stop using Clang for XDP.

For E810, do you still see update udp4_dp_filter map fail? SRIOV is not required for XDP per my understanding, and can you share both MtlManager and IMTL running log?

[ricmli]

Looks like some xdp-tools/libbpf issue with clang.

[eugenevt]

I can confirm that MtlManager compiled with clang, gives map update error, compiled with gcc not, on both cards.

[frankdjx]

https://github.com/OpenVisualCloud/Media-Transport-Library/pull/896 should fix the update error, at least it update successfully in my local clang build.

[eugenevt]

I have tested the fix, can confirm that now clang compilation works, I have the data.