Hi matan:
I have enabled mlx5 hotplug based on the failsafe pmd:
"--vdev", "net_failsafe0,mac=04:e8:92:7d:dd:e4,dev(08:00.0)", "-b", "08:00.0"
08:00.0 is mlx5 NIC.
The app started successfully.

However, I had some problems verifying the hotplug function. Here are the steps:
echo 1 > /sys/bus/pci/devices/0000:08:00.0/remove
echo 1 > /sys/bus/pci/rescan

The app had the following error:
EAL: PCI device 0000:08:00.0 on NUMA socket 0
EAL:   probe driver: 15b3:1017 net_mlx5
net_mlx5: port 2 cannot get MAC address, is mlx5_en loaded? (errno: Function not implemented)
net_mlx5: probe of PCI device 0000:08:00.0 aborted after encountering an error: No such device
EAL: Driver cannot attach the device (08:00.0)
EAL: Failed to attach device on primary process
net_failsafe: sub_device 0 probe failed (No such device)


Look at the code it is through the ioctl function to obtain the MAC address.
I wonder if there are other configurations that have not been done, causing this problem

Thanks!