When a primary process is launched with some whitelisted PCIe devices, the secondary process will not detect NICs if the exact same whitelisting parameters are not given.

Eg, if I pass :
sudo ./testpmd -w 01:00.0 -w 01:00.1 --proc-type primary --  

Then if I just run sudo ./testpmd --proc-type secondary --  

I will have :

EAL: PCI device 0000:01:00.0 on NUMA socket 0
EAL:   probe driver: 8086:10fb net_ixgbe
EAL: secondary process attach failed, ethdev doesn't existEAL: Requested device 0000:01:00.0 cannot be used
EAL: PCI device 0000:01:00.1 on NUMA socket 0
EAL:   probe driver: 8086:10fb net_ixgbe
EAL: secondary process attach failed, ethdev doesn't existEAL: Requested device 0000:01:00.1 cannot be used
EAL: PCI device 0000:03:00.0 on NUMA socket 0
EAL:   probe driver: 8086:10fb net_ixgbe
...

I would personally expect the secondaries to be able to open only the whitelisted in the secondary, or maybe all devices.

If I launch the secondary with the same -w, the secondary will be able to access the devices as expected :
sudo ./testpmd -w 01:00.0 -w 01:00.1 --proc-type secondary --  

EAL: PCI device 0000:01:00.0 on NUMA socket 0
EAL:   probe driver: 8086:10fb net_ixgbe
EAL: PCI device 0000:01:00.1 on NUMA socket 0
EAL:   probe driver: 8086:10fb net_ixgbe

Thanks,
Tom