April 1, 1981
166.2 IBM VM/370 System Programmer's Guide

The user doubleword can also be used as a security code or provide
additional information for subfunctions such as IDENTIFY and REJECT. Yeu can specify a zero data length for any V"CF transaction. The effect
of this is that only the external interrupt message header with user
doubleword is transmitted or DIAGNOSE X'68' RETURN CODES The virtual machine initiating a VMCF request receives a return code in
the general register specified as "Ry" in the DIAGNOSE The
return code indicates successful completion of the request or error
conditions associated with the request. Figure 20 is a description cf
all possible return codes returned to a virtual machine executing the DIAGNOSE X'68' subfunction. I I I I Return I I I Code I Meaning I , I I 0 IThe normal response. Indicates successful completion of al ! Irequest or successful initiation of a request. For example, I I Ifor an AUTHORIZE request, 0 indicates that the AUTHORIZEI I Ifunction is complete; for a SEND request, 0 indicates that thel I ISEND was successfully initiated. The SEND request, of course, I I Iwould not be complete until the final RESPONSE externall I iinterrupt was received by the source virtual machine. I • I I 1 IInvalid virtual buffer address or length. A virtual machinel I lattempted to execute a VKCF subfunction but specified ani I I invalid address or length: I I I I I I. External interrupt buffer not within virtual storage. I I I. External interrupt buffer address not doubleword aligned. I I I. Message data or buffer not within virtual storage. I I I. External interrupt buffer less than the standard messagel I I header length. I I I I 2 IInvalid subfunction code. A virtual machine attempted tol I lexecute a VKCF subfunction but specified an unsupportedi I Isubfunction code. I I t I 3 IProtocol violation. A virtual machine attempted to execute al I Isubfunction which would violate the defined protocol: I I I I I I· Cancel a message it did not originate. I I I. Reply to a message not sent via SEND/RECV. I , ,. REJECT a message that it originated. I I I. Executed more than one RECEIVE to a SEND or SEND/RECVI , I request. I I ,4 ,Source virtual machine not authorized. A virtual machinel , lattempted to execute a subfunction (other than AUTHORIZE) butl I Iwas not authorized to use VMCF (had not successfully executedl lithe AUTHORIZE subfunction). I J
Figure 20. DIAGNOSE Code X'68' Return Codes (Part 1 of 3)
Part 2. Control program (CP) 167