3PAR Driver modifications to support QOS

Currently, the OpenStack HP 3PAR Fibre Channel (FC) and iSCSI Drivers
do not support Quality of Service (QoS) extra specs. The QoS settings
added in this patch include;
•   maximum MB/second (maxBWS)
•   maximum IO/second (maxIOPS)
These new extra specs will be scoped keys, the scoping will be
qos:maxBWS and qos:maxIOPS. A new key hp3par:vvs was also
added to allow the admin to predefine QOS settings on a 3PAR
virtual volume set and any volume created would be added
to that predefined volume set.

The 3PAR storage arrays set these values on virtual volume sets,
not the actual volume. So the change includes creating a virtual
volume set with these settings and then adding the volume to the
volume set.
1.  Max IO/S & Max MB/S are not QoS guarantees
2.  These are per volume maximums which the 3PAR is guaranteed
not to exceed.
3.  Settings these values does not guarantee these performance
rates will be achievable

DocImpact

Implements blueprint 3par-qos-support

Change-Id: I69031c6d3febe11dd5f9ff17095b86f3fe72a2a4
Merge "3PAR Driver modifications to support QOS"