z/VM: CP Commands and Utilities Reference - z/VM - IBM

DEFINE DIAGNOSE
Usage Notes
162 z/VM: CP Commands and Utilities Reference
and you do not specify PROT for this command, you are disabling protection
and allowing the ESM to dynamically enable that protection.
CHECKR15 YES
indicates that the diagnose router should check register 15 upon return from the
diagnose handler.
CHECKR15 NO
indicates that the diagnose router should not check register 15 upon return from
the diagnose handler.
1. If you do not specify the ENABLE operand, a new DIAGNOSE code is initially
in a disabled state after being defined. CP treats disabled DIAGNOSE codes
as if they were never defined. If you try to use a disabled DIAGNOSE code in
a program, CP will give you a program check specification exception.
2. To load the DIAGNOSE processing code into CP’s system execution space,
use the CPXLOAD command (page 101).
3. To activate a new DIAGNOSE code after defining it, use the ENABLE
DIAGNOSE command (page 429).
4. To change the definition of an existing DIAGNOSE code after initialization, use
the MODIFY DIAGNOSE command (page 615).
5. To display information about a DIAGNOSE code (status, entry point name, and
privilege class), use the QUERY DIAGNOSE command (page 779).
6. To display the real address of the CP DIAGNOSE code table block for a
DIAGNOSE code, use the LOCATE DGNBK command (page 533).
7. To deactivate a DIAGNOSE code after defining it, use the DISABLE
DIAGNOSE command (page 266).
8. Once defined, DIAGNOSE codes cannot be deleted. They may be altered in
various appropriate ways, but they remain in existence until a SHUTDOWN or
RESTART IPL is done.
9. To remove the DIAGNOSE processing code from CP’s system execution
space, use the CPXUNLOAD command (page 107).
10. Many external security managers (ESMs) do not support DIAGNOSE codes
above X'03FC'. For this reason, CP does not support DIAGNOSE codes above
X'03FC'. The DIAGNOSE codes between X'0000' and X'03FC' are divided as
follows:
X'0000' to X'00FC'
Reserved for IBM use
X'0100' to X'01FC'
Reserved for customer use
X'0200' to X'03FC'
Reserved for IBM use.
11. When CHECKR15 YES is specified, the diagnose router will check register 15
on return from the diagnose handler. If register 15 contains:
RC = 0
Processing was successful. Complete the guest instruction.
RC = 4
Processing failed due to a condition which would cause a guest
program check. Simulate guest program interruption passed in R0.
RC = 8
Nullify the instruction.