$VDSBK 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.

  $VDSBK Prolog Top of page
 DESCRIPTION: Relocation mapping for HCPVDSBK
 DSECT      : $VDSBK
 FUNCTION   : LGRVDSBK describes those fields of the VDSBK 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.
 DELETED BY : HCPRLDRL - Release storage associated with an RDP
 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 HCPVDSBK 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.
  $VDSBK Control Block Content Top of page

 $VDSBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure $VDSBK Relocation mapping for HCPVDSBK 00000001 $VDS_VER 1 Mapping version number for this DSECT. Version is independent of the CP level and need only be changed when this DSECT is changed. The convention is to increment by 1. 0000 0 Signed 2 $VDS_HDRL Header length (in bytes) 0002 2 Signed 2 $VDS_BITL Length of mapped bits (in bytes) 0004 4 Signed 4 * Reserved for future use 00000008 $VDS_HDLN *-$VDSBK Length of header (bytes) Bit map: Contains the VDSBK flags that are subject to relocation. These bits are defined sequentially, regardless of how they are defined in HCPVDSBK. 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 $VDS_BITS (0) Bit map area 0008 8 Bitstring 1 $VDS0 1... .... $VDSAUCR X'80' $VDSAUCR VDSCFLG 00000001 $VDS_BLEN *-$VDS_BITS Length of bit map area Data: Contains all HCPVDSBK 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. 0009 9 Bitstring 1 $VDS_DATA (0) Start of data map 0009 9 Bitstring 4 $VDSVFC VFCBK pointer 000D 13 Bitstring 4 $VDSUCSB UCSB Data Block pointer 00000011 $VDS_LEN *-$VDSBK Total length, in bytes 00000003 $VDS_SZ ($VDS_LEN+7)/8 Size in doublewords
  $VDSBK Storage Layout Top of page
*** $VDSBK - Relocation mapping for HCPVDSBK
*     +-------------+-------------+---------------------------+
*   0 | $VDS_HDRL   | $VDS_BITL   |///////////////////////////|
*     +------+------+-------------+------+--------------------+
*   8 |$VDS0 |         $VDSVFC           |     $VDSUCSB-      |
*     +------+---------------------------+--------------------+
*  10 |-(00D)| 11
*     +------+
*** $VDSBK - Relocation mapping for HCPVDSBK
  $VDSBK Cross Reference Top of page
Symbol         Dspl Value
-------------- ---- -----
$VDS_BITL      0002
$VDS_BITS      0008
$VDS_BLEN      0008 00000001
$VDS_DATA      0009
$VDS_HDLN      0004 00000008
$VDS_HDRL      0000
$VDS_LEN       000D 00000011
$VDS_SZ        000D 00000003
$VDS_VER       0000 00000001
$VDSAUCR       0008 80
$VDSUCSB       000D
$VDSVFC        0009
$VDS0          0008
This information is based on z/VM 6.3.0 Last updated on 22 May 2013 at 13:56:39 EDT.
Copyright IBM Corporation, 1990, 2013