Scheduling an SRB in an Independent Enclave

Suppose an address space representing a subsystem uses the specialized processing services of a supporting address space to satisfy a work request. The subsystem creates an independent enclave that is used by an SRB executing in the supporting address space on behalf of the work request. Part of the work request executes under an SRB in the subsystem address space, so that SRB uses the same enclave.

Figure 7 shows the two address spaces.

Figure 7. Creating an Independent Enclave and Scheduling an SRB

• Connect as a work manager

  Subsystem address space A issues IWM4CON to connect to workload management with WORK_MANAGER=YES specified or defaulted. This makes work management services, including enclave services, available to the connecting address space.

• Create enclave Z

  Subsystem address space A wants to manage multiple SRBs (SRBs 1 and 2) as a unit, so address space A creates an independent enclave Z by issuing IWM4ECRE. Subsystem address space A is the home address space, and is the owner of enclave Z. Any work that the subsystem and its supporting address space B process can be managed as an enclave. Classification information is passed in with IWM4ECRE so workload management can assign the enclave to a service class or performance group and manage to those goals.

  For more information, refer to Performance Management of Address Spaces with Enclaves.

• Schedule SRB 1 into enclave Z

  The subsystem address space then schedules an SRB, SRB 1, to execute in its own address space and to be managed as part of enclave Z, using the IEAMSCHD macro:

  IEAMSCHD ENV=PRIMARY,
           EPADDR=entry_point_address,
           PRIORITY=ENCLAVE,
           ENCLAVETOKEN=tokenZ

  Where the subsystem address space has defined:

  tokenZ          FL4         The enclave token for enclave Z

• Schedule SRB 2 into enclave Z

  The subsystem address space then schedules an SRB (SRB 2) to execute in supporting address space B and to be managed as part of enclave Z, using the IEAMSCHD macro:

  IEAMSCHD ENV=STOKEN,
           TARGETSTOKEN=tokenB,
           EPADDR=entry_point_address,
           PRIORITY=ENCLAVE,
           ENCLAVETOKEN=tokenZ

• Wait for the SRBs to complete and delete enclave Z

  The subsystem waits for the SRBs to complete the request, then deletes the enclave using the IWM4EDEL macro and returns to the caller.