pflash is the name of the firmware update tool. See Update the Firmware (Oracle Linux) for more information.
pflash -d device-path num_vfs 4
where device-path is the path to flash device, in [domain:]<bus>:<slot>.<func> format. . The sample output above displays the value num_vfs 4 which enables four VFs. Valid num_vfs include 0,1,2,4,8,16, or 32 to show or configure supported number of VFs.
The value 0 reverts back to a nonvirtualized mode or PF. This setting is persistent with reboots.
pflash -d device-path num_vfs