BLKIO | Back to Index page

| Prolog Control Block Contents BLKIO 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.

BLKIO Prolog | Top of page

     NAME       : HCPBLKIO
     DESCRIPTION: *BLOCKIO Device Connection Data
     DSECT      : BLKIO
     FUNCTION   : This DSECT maps data representing a successful
                  connection to a device by a virtual machine
                  using the *BLOCKIO system service
     LOCATED BY : VMDBLKIO field in VMDBK
                  VDEVBIOA field in VDEV
     CREATED BY : HCPBIO
     DELETED BY : HCPBIO
     SERIALIZED : Unique task execution
                  VMDBK dispatch lock.
     RELOCATION CONSIDERATIONS : None

BLKIO Control Block Content | Top of page

     BLKIO DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      BLKIO          *BLOCKIO Device Connection Data
    0000    0 Signed       4 BLKNEXT        Address of next BLKIO Block
    0004    4 Bitstring    1 BLKRC          SEVER return code
    0005    5 Bitstring    1 BLKSTAT        BLKIO status
              1... ....      BLKSVRD        X'80' BLKSVRD SEVER is Pending
              .1.. ....      BLKRESET       X'40' BLKRESET RESET is Pending
    0006    6 Bitstring    2 BLKPATH        IUCV path for this device
    0008    8 Signed       4 BLKOFFCP       CP offset for minidisk. Must be
                                            treated as a signed value. (May
                                            be negative.)
            BLKDBCCT is used to indicate the number of outstanding
            processes in HCPDBC.  It is used to indicate that i/o
            may be in progress for a particular request.
            Thus BLKDBCCT and BLKDBIAD both must be 0 for there to be
            no outstanding *BLOCKIO for this device.
    000C   12 Signed       4 BLKDBCCT       Count of processes in HCPDBC
    0010   16 Signed       4 BLKDBIAD       Chain of outstanding DBIRQs
    0014   20 Signed       4 BLKDBCWK       Chain of outstanding sends to
                                            *BLOCKIO
    0018   24 Bitstring   16 BLKCPARM (0)   User connect parameter list
    0018   24 Signed       4 BLKSIZE        Block size of user's disk
    001C   28 Signed       4 BLKOFFST       User's requested offset
    0020   32 Signed       2 BLKVDEV        Virtual device address
    0022   34 Bitstring    6 *              Reserved for future IBM use
    0028   40 Bitstring   16 BLKPARMA (0)   ACCEPT parameter list
    0028   40 Signed       4 BLKSTART       User's starting block
    002C   44 Signed       4 BLKEND         User's ending block
    0030   48 Bitstring    1 *              Reserved for Future IBM Use
    0031   49 Bitstring    1 BLKFLAGS       Device status flags
              .... ...1      BLKDEVRD       X'01' BLKDEVRD Virtual device is
                                            read only
    0032   50 Bitstring    2 *              Reserved for Future IBM Use
    0034   52 Signed       4 BLKSPIRA       Special IRA for SEVER processing
    0038   56 Signed       4 BLKVDEVA       Virtual device block address
    003C   60 Signed       4 BLKDINFO       Address of device information
    0040   64 Signed       4 BLKSAVBK       Caller's save block
    0048   72 Dbl-Word     8 * (0)          Ensure Double Word Boundary
    0048   72 Dbl-Word     8 BLKLOWN (3)    BLKIO lock
    0060   96 Dbl-Word     8 * (0)          Ensure Double Word Boundary
    0060   96 Bitstring   40 BLKPARML       IUCV parameter list
              00000011       BLKDSIZE       (*-BLKIO+7)/8 Size, in
                                            doublewords, of BLKIO

BLKIO Storage Layout | Top of page

    *** BLKIO - *BLOCKIO Device Connection Data
    *
    *     +---------------------------+------+------+-------------+
    *   0 |         BLKNEXT           |BLKRC |:STAT |  BLKPATH    |
    *     +---------------------------+------+------+-------------+
    *   8 |         BLKOFFCP          |         BLKDBCCT          |
    *     +---------------------------+---------------------------+
    *  10 |         BLKDBIAD          |         BLKDBCWK          |
    *     +---------------------------+---------------------------+
    *  18 |         BLKSIZE           |         BLKOFFST          |
    *     +-------------+-------------+---------------------------+
    *  20 |  BLKVDEV    |/////////////////////////////////////////|
    *     +-------------+-------------+---------------------------+
    *  28 |         BLKSTART          |          BLKEND           |
    *     +------+------+-------------+---------------------------+
    *  30 |//////|:FLAGS|/////////////|         BLKSPIRA          |
    *     +------+------+-------------+---------------------------+
    *  38 |         BLKVDEVA          |         BLKDINFO          |
    *     +---------------------------+---------------------------+
    *  40 |         BLKSAVBK          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *  48 |                                                       |
    *     =                       BLKLOWN                         =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  60 |                                                       |
    *     =                       BLKPARML                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  88
    *
    *** BLKIO - *BLOCKIO Device Connection Data

BLKIO Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    BLKCPARM       0018
    BLKDBCCT       000C
    BLKDBCWK       0014
    BLKDBIAD       0010
    BLKDEVRD       0031 01
    BLKDINFO       003C
    BLKDSIZE       0060 00000011
    BLKEND         002C
    BLKFLAGS       0031
    BLKLOWN        0048
    BLKNEXT        0000
    BLKOFFCP       0008
    BLKOFFST       001C
    BLKPARMA       0028
    BLKPARML       0060
    BLKPATH        0006
    BLKRC          0004
    BLKRESET       0005 40
    BLKSAVBK       0040
    BLKSIZE        0018
    BLKSPIRA       0034
    BLKSTART       0028
    BLKSTAT        0005
    BLKSVRD        0005 80
    BLKVDEV        0020
    BLKVDEVA       0038

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:27:06 EDT.
Copyright IBM Corporation, 1990, 2020