$VDSBK | Back to Index page

| Prolog Control Block Contents $VDSBK DSECT 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

     NAME       : LGRVDSBK
     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.
     CREATED BY : HCPRLFDF - VDSBK Formatter for LGR
     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 7.2.0 Last updated on 24 Jun 2020 at 09:32:16 EDT.
Copyright IBM Corporation, 1990, 2020