Comment 10 for bug 1892361

no we do not take account of /sys/class/net/eno2/device/sriov_numvfs when determining the type
its based solely on the pci config space capablities

chaning /sys/class/net/eno2/device/sriov_numvfs form 0 to another value should not affect the pcie capabilities.

that is a common misconception however.
this is the logic that determins the device type
https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L7125-L7163

if you have a device that exposes /sys/class/net/eno2/device/sriov_numvfs
without the "virt_functions" capablity or a device wehre that change based the number
of VFs allcoated you should file a driver bug with your nic vendor as both behaviors would be incorrect.

this predates queens but i dont think we will backport it further then queens so i have added the different releases between master and queens.