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

f i , I Return I Meaning , I Code , , I I .. ,5 IUser not available. A virtual machine attempted to execute al I ,function and specified a virtual machine currently notl I ,available for VMCF communication: I , , I I I. Not logged on. , I I· Not authorized for VMCF communication. I I I. Virtual machine authorized SPECIFIC for some otherl I I virtual machine. , I -r I 6 Protection violation. A virtual machine attempted to execute al I VMCF function that would result in a StORE or FETCH protectionl I violation. The virtual machine specified a data or bufferl I address that contained a storage key other than its current PSi, I key (assume key was nonzero). This return code is also set if I I a virtual machine attempts to receive data in a CP-owned sharedl I segment. , I .. I 7 SENDX data too large. A virtual machine attempted to execute al I SEND X request but specified a SENDX data length larger than the, I sink virtual machine external interrupt buffer. I I I I , 8 IDuplicate message. A virtual machine attempted to execute al I ISEND-type function and specified a message ID and virtuall I Imachine userid for which there was already an active message. , I I I 9 ITarget virtual machine in QUIESCE status. A virtual machine, I lattempted to execute a SEND-type function and specified a sinkl I ,virtual machine userid of a virtual machine in QUIESCE status. I I I -t 110 IMessage limit exceeded. A virtual machine attempted to executel I la SEND sub function but already had 50 messages active. The, I Ivirtual machine should clear any pending RESPONSE externall I ,interrupts or CANCEL previously sent messages in order tol I ,continue processing. , I I .. 111 IREPLY canceled. The source virtual machine executed a CANCEL, I Ito a previous SEND/RECV request. The sink virtual machine had, I lalready RECEIVED the message but had not yet executed a REPLy.t 1 IThe sink virtual machine REPLY in this case is canceled. The' I Isink virtual machine will get return code 12 (message notl , 'found) when it executes the REPLY subfuncticn. , I I .. 112 ,Message not found. A virtual machine attempted to execute al I Isubfunction and specified a message ID and virtual machine, I luserid for a message that does not exist. The message may have, I lexisted at one time but could have been cancelled by tbet I loriginator. , I -.I Figure 20. DIAGNOSE Code X'68' Return Codes (Part 2 of 3)
168 IB" VM/370 System programmer's Guide