Trivial low level QoS configuration proposition

===============================================

Basically there is a set of QoS related low-level configuration parameters.

All these parameter names are prefixed by "qos_" string. Here is a full

list of these parameters:

  qos_max_vls    - The maximum number of VLs that will be on the subnet

  qos_high_limit - The limit of High Priority component of VL Arbitration

                   table (IBA 7.6.9)

  qos_vlarb_low  - Low priority VL Arbitration table (IBA 7.6.9) template

  qos_vlarb_high - High priority VL Arbitration table (IBA 7.6.9) template

                   Both VL arbitration templates are pairs of VL and weight

  qos_sl2vl      - SL2VL Mapping table (IBA 7.6.6) template. It is a list

                   of VLs corresponding to SLs 0-15 (Note the VL15 used

                   here means drop this SL)

Typical default values (hard-coded in OpenSM initialization) are:

  qos_max_vls 15

  qos_high_limit 0

  qos_vlarb_low 0:0,1:4,2:4,3:4,4:4,5:4,6:4,7:4,8:4,9:4,10:4,11:4,12:4,13:4,14:4

  qos_vlarb_high 0:4,1:0,2:0,3:0,4:0,5:0,6:0,7:0,8:0,9:0,10:0,11:0,12:0,13:0,14:0

  qos_sl2vl 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,7

The syntax is compatible with rest of OpenSM configuration options and

values may be stored in OpenSM config file (cached options file).

In addition to the above, we may define separate QoS configuration

parameters sets for various target types. As targets, we currently support

CAs, routers, switch external ports, and switch's enhanced port 0. The

names of such specialized parameters are prefixed by "qos_<type>_"

string. Here is a full list of the currently supported sets:

  qos_ca_  - QoS configuration parameters set for CAs.

  qos_rtr_ - parameters set for routers.

  qos_sw0_ - parameters set for switches' port 0.

  qos_swe_ - parameters set for switches' external ports.

Examples:

  qos_sw0_max_vls 2

  qos_ca_sl2vl 0,1,2,3,5,5,5,12,12,0,

  qos_swe_high_limit 0