19/05/2020 20:20, PATRICK KEROULAS: > Hello, > > I'm trying to build an accurate capture device based on Mellanox > Connect-X5 with following requirements: > - capture every incoming packets with hardware timestamps > - output: pcap with timestamps in nanoseconds > My problem is that the packets forwarded to `dpdk-pdump` carry raw > timestamps from NIC clock.
Please could you describe how you use dpdk-pdump? Is it using the mlx5 PMD or pcap PMD? > mlx5 part of libibverbs includes a ts-to-ns converter which takes the > instantaneous clock info. It's unused in dpdk so far. I've tested it in the > device/port init routine and the result looks reliable. Since this approach > looks very simple, compared to the time sync mechanism, I'm trying to > integrate. > > The conversion should occur in the primary process (testpmd) I suppose. > 1) The needed clock info derives from ethernet device. Is it possible to > access that struct from a rx callback? > 2) how to attach the nanosecond to mbuf so that `pdump` catches it? > (workaround: copy `mbuf->udata64` in forwarded packets.) > 3) any other idea? The timestamp is carried in mbuf. Then the conversion must be done by the ethdev caller (application or any other upper layer).
