[dpdk-users] no driver found for pcap-based virtual NIC (eth_pcap0)

["Douglas, Frederick E" <fed2@illinois.edu>]

I'm new to DPDK. I've gotten the basics working, but I'm having trouble with the .pcap file-based virtual interface. The EAL is failing to set things up when I ask it to use a pcap virtual interface, with:

--vdev 'eth_pcap0,rx_pcap=/full/path/to/iperf_udp.pcap,tx_pcap=/full/path/to/NEW.pcap'

It says "EAL: no driver found for eth_pcap0; EAL: failed to initialize eth_pcap0 device; PANIC in rte_eal_init(): Cannot init pmd devices".

Everything works fine with the all-in-memory virtual interfaces (--vdev=eth_ring0 --vdev=eth_ring1). I even confirmed (with chunks of code from https://github.com/marty90/DPDK-Dump) that I can get testpmd to use a pcap_dumper_t to dump the traffic it processes to a .pcap file.

There doesn't seem to be anything in the setup.sh consolidated setup menu about pcap, and the part of the manual describing the pcap vdev (http://dpdk.org/doc/guides/nics/pcap_ring.html#libpcap-based-pmd) doesn't mention anything that needs to be done - in fact it's in the manual right together with the in-memory ring-based driver. I found a drivers/net/pcap directory with a Makefile that had never been made, but nothing changed after making it.

In case any of this might matter:
=I'm trying to run testpmd (with some slight modifications, which work as expected with the ring vdev)
=Ubuntu 14.04; DPDK configured for x86_64-native-linuxapp-gcc
=1024 2MiB hugepages

So, does anyone have any idea? I have a feeling I'm missing something really simple... but I'm out of ideas about what that might be!