IOPBK | Back to Index page

| Prolog Control Block Contents IOPBK 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.

IOPBK Prolog | Top of page

     NAME       : HCPIOPBK
     DESCRIPTION: I/O Passthrough Block
     DSECT      : IOPBK
     FUNCTION   : A IOPBK contains information related to the
                  execution of a virtual machine eligible to use
                  the SIE Assist for its dedicated I/O.
     LOCATED BY : VMDIOPBK  Field of the preferred guest's Origin
                  VMDBK
                  The first part of the IOPBK is a TRQBK, so it may
                  also appear on the timer supervisor queue, or be
                  stacked on the VMDBK.
     CREATED BY : HCPBVM    When a user logs on in the V=F area.
     DELETED BY : HCPUSO    When the V=F user logs off.
     RELOCATION CONSIDERATIONS : None

IOPBK Control Block Content | Top of page

     IOPBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      IOPBK          I/O Passthrough Block
         OPTRQBK DS    (TRQSIZE)D         Timer Request Block
    0000    0 Dbl-Word     8 IOPTRQBK (7)   Timer Request Block
         <CMT>*  DS    (LKWRDSIZ)D        Lockword for synchronizing
    0038   56 Dbl-Word     8 IOPLKWRD (3)   Lockword for synchronizing the
                                            timer exit and the cancellation
                                            routine
    0050   80 Signed       4 IOPTMCNT       count of entries to CFM while I/O
                                            Passthrough was active
    0054   84 Signed       4 IOPXTCNT       count of timer expirations before
                                            cancellations
    0058   88 Signed       4 IOPQQCNT       count of cancellations in less
                                            than 1024 microseconds
    005C   92 Signed       4 IOPLLCNT       count of cancellation after more
                                            than 64 sec
    0060   96 Signed       4 IOPXCNTS (16)  array of counts of cancellations
                                            in interval with lower bound
                                            1024*(2**i) microseconds (i = 0
                                            15)
    00A0  160 Signed       4 *              Reserved for Future IBM Use
    00A4  164 Bitstring    1 IOPACTZN       Active zone number
    00A5  165 Bitstring    1 * (3)          Reserved
    00A8  168 Signed       4 *              Reserved for Future IBM Use
    00AC  172 Signed       4 *              Reserved for Future IBM Use
    00B0  176 Dbl-Word     8 *              Reserved for Future IBM Use
              000000B8       IOPLEN         *-IOPBK Size of the IOPBK in
                                            bytes
              00000017       IOPSIZE        (IOPLEN+7)/8 Size of the IOPBK in
                                            doublewords

IOPBK Storage Layout | Top of page

    *** IOPBK - I/O Passthrough Block
    *
    *     +-------------------------------------------------------+
    *   0 |                                                       |
    *     =                       IOPTRQBK                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  38 |                                                       |
    *     =                       IOPLKWRD                        =
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  50 |         IOPTMCNT          |         IOPXTCNT          |
    *     +---------------------------+---------------------------+
    *  58 |         IOPQQCNT          |         IOPLLCNT          |
    *     +---------------------------+---------------------------+
    *  60 |                                                       |
    *     =                       IOPXCNTS                        =
    *     |                                                       |
    *     +---------------------------+------+--------------------+
    *  A0 |///////////////////////////|:ACTZN|////////////////////|
    *     +---------------------------+------+--------------------+
    *  A8 |///////////////////////////|///////////////////////////|
    *     +---------------------------+---------------------------+
    *  B0 |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *  B8
    *
    *** IOPBK - I/O Passthrough Block

IOPBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    IOPACTZN       00A4
    IOPLEN         00B0 000000B8
    IOPLKWRD       0038
    IOPLLCNT       005C
    IOPQQCNT       0058
    IOPSIZE        00B0 00000017
    IOPTMCNT       0050
    IOPTRQBK       0000
    IOPXCNTS       0060
    IOPXTCNT       0054

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:28:37 EDT.
Copyright IBM Corporation, 1990, 2020