$IOCM | Back to Index page

| Prolog Control Block Contents $IOCM 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.

$IOCM Prolog | Top of page

     NAME       : LGRIOCM
     DESCRIPTION: Relocation mapping for HCPIOCM
     DSECT      : $IOCM
     FUNCTION   : LGRIOCM describes those fields of the IOCM block
                  that will be relocated 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 : HCPRLFAF - AMSG/IOCM 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 HCPIOCM 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.

$IOCM Control Block Content | Top of page

     $IOCM DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      $IOCM          Relocation mapping for HCPIOCM
              00000001       $IOCM_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 $IOCM_HDRL     Header length (in bytes)
    0002    2 Signed       2 $IOCM_BITL     Length of mapped bits (in bytes)
    0004    4 Signed       4 *              Reserved for future use
              00000008       $IOCM_HDLN     *-$IOCM Length of header (bytes)
          Bit map: Contains the IOCM flags that are subject to
                   relocation. These bits are defined sequentially,
                   regardless of how they are defined in HCPIOCM.
                   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 $IOCM_BITS (0) Bit map area
    0008    8 Bitstring    1 $IOCM0
              1... ....      $IOCMNBST      X'80' $IOCMNBST IOCMFLAG
              00000001       $IOCM_BLEN     *-$IOCM_BITS Length of bit map
                                            area
          Data:    Contains all HCPIOCM 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 $IOCM_DATA (0) Start of data map
    0009    9 Bitstring    4 $IOCMNEXT      Pointer to next IOCM block
    000D   13 Bitstring    4 $IOCMBKID      IDs storage area as an IOCM block
    0011   17 Bitstring    2 $IOCMSCNT      Sense data count
    0013   19 Bitstring   32 $IOCMSNS       Sense Data
    0033   51 Bitstring   64 $IOCMIRB       IRB data
              00000073       $IOCM_LEN      *-$IOCM Total length, in bytes
              0000000F       $IOCM_SZ       ($IOCM_LEN+7)/8 Size in
                                            doublewords

$IOCM Storage Layout | Top of page

    *** $IOCM - Relocation mapping for HCPIOCM
    *
    *     +-------------+-------------+---------------------------+
    *   0 | $IOCM_HDRL  | $IOCM_BITL  |///////////////////////////|
    *     +------+------+-------------+------+--------------------+
    *   8 |$IOCM0|        $IOCMNEXT          |    $IOCMBKID-      |
    *     +------+-------------+-------------+--------------------+
    *  10 |-(00D)| $IOCMSCNT   |                                  |
    *     +------+-------------+                                  |
    *  18 |                                                       |
    *     =                       $IOCMSNS                        =
    *     |                    +----------------------------------+
    *     |                    |                                  |
    *     +--------------------+                                  |
    *  38 |                                                       |
    *     =                       $IOCMIRB                        =
    *     |                    +----------------------------------+
    *     |                    | 73
    *     +--------------------+
    *
    *** $IOCM - Relocation mapping for HCPIOCM

$IOCM Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    $IOCM_BITL     0002
    $IOCM_BITS     0008
    $IOCM_BLEN     0008 00000001
    $IOCM_DATA     0009
    $IOCM_HDLN     0004 00000008
    $IOCM_HDRL     0000
    $IOCM_LEN      0033 00000073
    $IOCM_SZ       0033 0000000F
    $IOCM_VER      0000 00000001
    $IOCMBKID      000D
    $IOCMIRB       0033
    $IOCMNBST      0008 80
    $IOCMNEXT      0009
    $IOCMSCNT      0011
    $IOCMSNS       0013
    $IOCM0         0008

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:32:06 EDT.
Copyright IBM Corporation, 1990, 2020