Purpose of function:
- Virtual Device Role Tagging: a mechanism by which the user will tag a device they have assigned to their guest with a specific role. The tag will be matched to the hardware address of the device and this mapping will be exposed to the guest OS through the use of metadata service/cloud-init.
-Trusted Virtual Functions: A new kernel feature allows Virtual Functions to become "trusted" by the Physical Function and perform some privileged operations, such as enabling VF promiscuous mode and changing VF MAC address within the guest. The inability to modify mac addresses in the guest prevents the users from being able to easily setup up two VFs in a fail-over bond in a guest. This spec aims to suggest a way for users to boot instances with trusted VFs.