The Group Configuration Table is an array of registers in BAR0 that controls the mapping of work queues to engines. The offset of the Group Configuration Table is given by the Group Configuration Offset field in the Table Offsets register. The number of groups is given by the Number of Groups field in GRPCAP. Software may configure the number of groups that it needs. Group Configuration registers beyond the number of groups available are reserved and may not be implemented in hardware.
Each active group contains one or more work queues and one or more engines. Any unused group must have both the WQs field and the Engines field equal to 0. Descriptors submitted to any WQ in a group may be processed by any engine in the group. Each active work queue must be in a single group. (An active work queue is one for which the WQ Size field of the corresponding WQCFG register is non-zero.) Any engine that is not in a group is inactive. See #671116 section 3.4 for more information on engines and groups.
Each GRPCFG register is divided into three sub-registers.
These registers are read-write while the device is Disabled and read-only otherwise. They are read-only at all times if the Configuration Support field in GENCAP is 0.