#9 Provide basic QoS support

[Eitan Zahavi]

Enhance OpenSM to enable a system administrator to
define a QoS policy for the entire fabric:

At first only basic functionality for setting VLArb and
SL2VL Map will be implemented.

The functionality will be exposed as part of
osmsh and first implemented in TCL as an
example flow.

When requirements will stabilize this will be promoted
to be a standard OpenSM procedure controlled by
command line arguments.

We can easily implement the following policy over IB:
1. Policy:
* Number of lowest latency service levels
* Relative BW for each low latency service level
* Number of higher latency service levels
* Relative BW for each higher latency service level
* Relative arbitration ratio between low and high
latency groups.
2. Verification:
* Scan the fabric for SL/VL capabilities required
by the requested policy. All devices should
meet them or abort
* Note that OPVL is a separate option and thus
it is the user responsibility
3. Assignment:
* Assign each SL2VL and VLArb tables on the fabric
accordingly.

EZ