Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### IOPBK

Prolog

Control Block Contents
IOPBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### IOPBK Prolog

     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=R area.
     DELETED BY : HCPUSO    When the V=R user logs off.

#### IOPBK Control Block Content

#### IOPBK DSECT

    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 IOPIFSNT       Address of the 16K block assigned
                                            to this user for use as the
                                            subchannel number table
    00A4  164 Bitstring    1 IOPACTZN       Active zone number
    00A5  165 Bitstring    1 * (3)          Reserved
    00A8  168 Signed       4 IOPCLRCC       CLEAR CHANNEL CONDITION CODE
    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

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

#### IOPBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    IOPACTZN       00A4
    IOPCLRCC       00A8
    IOPIFSNT       00A0
    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 V4R3.0. Last updated on 30 Apr 2002 at 16:37:56 EDT.
Copyright IBM Corporation, 1990, 2002