$MSGBK Back to Index page
Control Block Contents 
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

  $MSGBK Prolog Top of page
 DESCRIPTION: Relocation mapping for HCPMSGBK
 DSECT      : $MSGBK
 FUNCTION   : LGRMSGBK describes those fields of the MSGBK that
              will be migrated to the destination system during
              guest relocation.
 LOCATED BY : This is a mapping of the RDODATA area within the
              RDOBK during guest relocation.
 RELOCATION CONSIDERATIONS : This control block is used during live guest
              relocation.  It is used to relocate a control block
              defined in a corresponding HCP COPY file.  Any
              fields or bits defined in HCPMSGBK which are
              required on the destination system must be defined
              here, and code must be added to migrate the field
              or bit during a relocation.
  $MSGBK Control Block Content Top of page

 $MSGBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure $MSGBK Relocation mapping for HCPMSGBK 00000001 $MSG_VER 1 Mapping version number 0000 0 Signed 2 $MSG_HDRL Header length (in bytes) 0002 2 Signed 2 $MSG_BITL Length of mapped bits (in bytes) 0004 4 Signed 4 * Reserved for future use 00000008 $MSG_HDLN *-$MSGBK Length of header (bytes) Bit map: Contains the MSGBK flags that are subject to relocation. These bits are defined sequentially, regardless of how they are defined in HCPMSGBK. This yields a consistent mapping that ensures compatibility when a guest is relocated between systems at differing service levels. Names in the comments column indicate the control block byte which contains the flag. This name is subject to change if the flag definition changes. ====> NEVER change bits which already exist here. ====> NEVER change the order of bits in this section. ====> ALWAYS add new bits at the end of this section, together with new flag bytes as required. 0008 8 Signed 2 $MSG_BITS (0) Bit map area 00000000 $MSG_BLEN *-$MSG_BITS Length of bit map area Data: Contains all HCPMSGBK data that is subject to relocation, except for flag bits, which are handled separately. All fields are defined as XLnn to avoid alignment warnings and to pack the data efficiently. ====> NEVER change fields which already exist here. ====> NEVER change the order of fields in this section. ====> ALWAYS add new fields at the end of this section. together with new flag bytes as required. 0008 8 Bitstring 1 $MSG_DATA (0) Start of data map 0008 8 Bitstring 4 $MSGFPNT -> RDO offset to next $MSGBK 000C 12 Bitstring 4 $MSGTGCLS TARGET MESSAGE CLASS 0010 16 Bitstring 4 $MSGSNDAD -> RDO offset to message data 0014 20 Bitstring 4 $MSGSNDLN SEND BUFFER LENGTH 00000018 $MSG_LEN *-$MSGBK Total length, in bytes 00000003 $MSG_SZ ($MSG_LEN+7)/8 Size in doublewords
  $MSGBK Storage Layout Top of page
*** $MSGBK - Relocation mapping for HCPMSGBK
*     +-------------+-------------+---------------------------+
*   0 | $MSG_HDRL   | $MSG_BITL   |///////////////////////////|
*     +-------------+-------------+---------------------------+
*   8 |         $MSGFPNT          |        $MSGTGCLS          |
*     +---------------------------+---------------------------+
*  10 |        $MSGSNDAD          |        $MSGSNDLN          |
*     +---------------------------+---------------------------+
*  18
*** $MSGBK - Relocation mapping for HCPMSGBK
  $MSGBK Cross Reference Top of page
Symbol         Dspl Value
-------------- ---- -----
$MSG_BITL      0002
$MSG_BITS      0008
$MSG_BLEN      0008 00000000
$MSG_DATA      0008
$MSG_HDLN      0004 00000008
$MSG_HDRL      0000
$MSG_LEN       0014 00000018
$MSG_SZ        0014 00000003
$MSG_VER       0000 00000001
$MSGFPNT       0008
$MSGSNDAD      0010
$MSGSNDLN      0014
$MSGTGCLS      000C
This information is based on z/VM 6.3.0 Last updated on 22 May 2013 at 13:56:36 EDT.
Copyright IBM Corporation, 1990, 2013