From: Zhu, Lingshan <redacted>
Sent: Tuesday, July 12, 2022 11:46 PM

quoted

When the user space which invokes netlink commands, detects that _MQ

is not supported, hence it takes max_queue_pair = 1 by itself.
I think the kernel module have all necessary information and it is the only
one which have precise information of a device, so it should answer precisely
than let the user space guess. The kernel module should be reliable than stay
silent, leave the question to the user space tool.

Kernel is reliable. It doesn’t expose a config space field if the field doesn’t exist regardless of field should have default or no default.
User space should not guess either. User space gets to see if _MQ present/not present. If _MQ present than get reliable data from kernel.
If _MQ not present, it means this device has one VQ pair.