[dpdk-users] TestPMD testing with VMX3NET Devices...

Rami Rosen roszenrami at gmail.com
Fri Sep 7 17:44:26 CEST 2018

Hi Jamie,
>Ok, can you clear something else up. Should I use the vfio-pci or the igb_uio driver/kernel module?

First there is a third option, which is binding with uio_pci_generic,
which is a generic kernel module.
When you bind with igb_uio, an entry called max_vfs will be generated
under the linux pci device sysfs entry.
Echoing an integer into max_vfs will generate DPDK VFs (if the DPDK
PMD support VFs; Intel and Mellnox
and other vendor nics do support it) as opposed to echoing into
sriov_numvs, which
generates a kernel module PF/PFs.
OTOH, You don't have max_vfs with vfio_pci and uio_pci_generic.

It says in the DPDK doc:
"If UEFI secure boot is enabled, the Linux kernel may disallow the use
of UIO on the system. Therefore, devices for use by DPDK should be
bound to the vfio-pci kernel module rather than igb_uio or

see also:
"5.4. Binding and Unbinding Network Ports to/from the Kernel Modules":

Hope this helps to clarify things,

Rami Rosen

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