Hi Bodong, PCI folk generally, I've found an issue with sriov_drivers_autoprobe not working as I would expect it to and I'd like to check if my expectations are incorrect or if it's not working as intended. Please consider the sequence below /sys/bus/pci/devices/0000:12:34.1# echo 0 > sriov_numvfs /sys/bus/pci/devices/0000:12:34.1# echo 0 > sriov_drivers_autoprobe /sys/bus/pci/devices/0000:12:34.1# echo 1 > sriov_numvfs (Let's say 0000:13:ab.0 is a VF of 0000:12:34.1) /sys/bus/pci/devices/0000:12:34.1# echo 0000:13:ab.0 > /sys/bus/pci/drivers/vfio-pci/bind -bash: echo: write error: No such device /sys/bus/pci/devices/0000:12:34.1# echo 1 > sriov_drivers_autoprobe /sys/bus/pci/devices/0000:12:34.1# echo 0000:13:ab.0 > /sys/bus/pci/drivers/vfio-pci/bind /sys/bus/pci/devices/0000:12:34.1# echo 0000:13:ab.0 > /sys/bus/pci/drivers/vfio-pci/unbind /sys/bus/pci/devices/0000:12:34.1# >From the above, we can see that having sriov_drivers_autoprobe unset prevents even manually binding a driver, after VF initialization. This seems unintentional, but it can be worked around by unsetting sriov_drivers_autoprobe. If this is how it was intended to work please let me know. If it is, then the documentation should be updated. It says: "Note that changing this file does not affect already-enabled VFs." But that does not appear to be true. Thanks for your help, and I'm sorry I'm not offering a fix, but I'm mostly a KVM engineer and don't know the PCI subsystem well, so I don't know how best to fix the check on sriov.drivers_autoload. Ben
