$MDGBK | Back to Index page

| Prolog Control Block Contents $MDGBK 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.

$MDGBK Prolog | Top of page

     NAME       : LGRMDGBK
     DESCRIPTION: Relocation mapping for HCPMDGBK
     DSECT      : $MDGBK
     FUNCTION   : LGRMDGBK describes those fields of the MDGBK 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 HCPMDGBK 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.

$MDGBK Control Block Content | Top of page

     $MDGBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      $MDGBK         Relocation mapping for HCPMDGBK
              00000001       $MDG_VER       1 Mapping version number
    0000    0 Signed       2 $MDG_HDRL      Header length (in bytes)
    0002    2 Signed       2 $MDG_BITL      Length of mapped bits (in bytes)
    0004    4 Signed       4 *              Reserved for future use
              00000008       $MDG_HDLN      *-$MDGBK Length of header (bytes)
          Bit map: Contains the MDGBK flags that are subject to
                   relocation. These bits are defined sequentially,
                   regardless of how they are defined in HCPMDGBK.
                   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 $MDG_BITS (0)  Bit map area
    0008    8 Bitstring    1 $MDG0
              1... ....      $MDG_CONFIG    X'80' $MDG_CONFIG MDG_STATUS
              00000001       $MDG_BLEN      *-$MDG_BITS Length of bit map
                                            area
          Data:    Contains all HCPMDGBK 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.
    0009    9 Bitstring    1 $MDG_DATA (0)  Start of data map
    0009    9 Bitstring    4 $MDG_NEXT      -> RDO offset to next $MDGBK
    000D   13 Bitstring    8 $MDG_APBUF_GAA1_G
                                            Guest abs addr 1st appl buffer
    0015   21 Bitstring    8 $MDG_APBUF_GAA2_G
                                            Guest abs addr 2nd appl buffer
    001D   29 Bitstring   16 $MDG_PROD_ID   Application product/release id
    002D   45 Bitstring    2 $MDG_BUFF_LEN  Total len (bytes) of appl buffer
    002F   47 Bitstring    2 $MDG_BUFF_LEN1 Length (bytes) of 1st buffer page
    0031   49 Bitstring    2 $MDG_BUFF_LEN2 Length (bytes) of 2nd buffer page
              00000033       $MDG_LEN       *-$MDGBK Total length, in bytes
              00000007       $MDG_SZ        ($MDG_LEN+7)/8 Size in
                                            doublewords

$MDGBK Storage Layout | Top of page

    *** $MDGBK - Relocation mapping for HCPMDGBK
    *
    *     +-------------+-------------+---------------------------+
    *   0 | $MDG_HDRL   | $MDG_BITL   |///////////////////////////|
    *     +------+------+-------------+------+--------------------+
    *   8 |$MDG0 |        $MDG_NEXT          |      (00D)-        |
    *     +------+---------------------------+--------------------+
    *  10 |       -$MDG_APBUF_GAA1_G         |      (015)-        |
    *     +----------------------------------+--------------------+
    *  18 |       -$MDG_APBUF_GAA2_G         |                    |
    *     +----------------------------------+                    |
    *     |                     $MDG_PROD_ID                      |
    *     |                                  +-------------+------+
    *  28 |                                  |$MDG_BUFF_LEN|(02F)-|
    *     +------+-------------+-------------+-------------+------+
    *  30 |-(02F)|:G_BUFF_LEN2 | 33
    *     +------+-------------+
    *
    *** $MDGBK - Relocation mapping for HCPMDGBK

$MDGBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    $MDG_APBUF_GAA1_G
                   000D
    $MDG_APBUF_GAA2_G
                   0015
    $MDG_BITL      0002
    $MDG_BITS      0008
    $MDG_BLEN      0008 00000001
    $MDG_BUFF_LEN  002D
    $MDG_BUFF_LEN1
                   002F
    $MDG_BUFF_LEN2
                   0031
    $MDG_CONFIG    0008 80
    $MDG_DATA      0009
    $MDG_HDLN      0004 00000008
    $MDG_HDRL      0000
    $MDG_LEN       0031 00000033
    $MDG_NEXT      0009
    $MDG_PROD_ID   001D
    $MDG_SZ        0031 00000007
    $MDG_VER       0000 00000001
    $MDG0          0008

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:32:04 EDT.
Copyright IBM Corporation, 1990, 2020