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

BKIBK

Prolog  

Control Block Contents  
   BKIBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


BKIBK Prolog

 NAME       : HCPBKIBK
 DESCRIPTION: Block I/O Block for DIAGNOSE X'250'
 DSECT      : BKIBK
 FUNCTION   : Main control block for the DIAGNOSE X'250'
              function; all other information can be found
              from this block.
 LOCATED BY : VDEVBKIA
 CREATED BY : HCPBICIN, during the initialization of the
              DIAGNOSE X'250' block I/O environment
 DELETED BY : HCPBICRE, during the removal of the
              DIAGNOSE X'250' block I/O environment
 SERIALIZED : The block I/O block lock, BKILOCK.
 RELOCATION CONSIDERATIONS : This control block is relocated as part of a live
              guest relocation (LGR).  The bits and fields that
              need to be relocated are defined in the
              corresponding LGRBKIBK COPY file.  Whenever changes
              are made to this control block, consideration must
              be given to any effects these changes will have on
              a relocation.  If any new fields or bits are
              defined, they may need to be relocated.  If
              existing bits or fields are changed, corresponding
              modifications may be required in the LGR version of
              this control block.  Consider also the effects of
              these changes on a relocation involving a back-level
              release of CP.
 COMMENTS   : Refer to the description of the VDEVBKIA
              field for information on the serialization
              for pointing to this block from the
              appropriate VDEV. There is one BKIBK for
              each VDEV for which a DIAGNOSE X'250'
              environment is initialized.

 

BKIBK Control Block Content


BKIBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BKIBK          Block I/O Block for DIAGNOSE X'250'
0000    0 Bitstring    1 BKISTAT        Block I/O function status
          .1.. ....      BKIRESET       X'40' BKIRESET A reset operation
                                        is pending. Note: this flag is
                                        set for serviceability - it is
                                        not checked, since BKIRMPD is
                                        always set as well by the time
                                        reset/remove status needs to be
                                        recognized.
          ..1. ....      BKIRELOC       X'20' BKIRELOC A clear is being
                                        performed due to pending I/O on
                                        this device timing out during
                                        Live Guest relocation. Note: this
                                        flag is set for serviceability -
                                        it is not checked, since BKIRMPD
                                        is always set as well by the time
                                        reset/remove status needs to be
                                        recognized.
0001    1 Bitstring    1 BKIFLAGS       Device status flags
          .... .1..      BKIRMPD        X'04' BKIRMPD A REMOVE request is
                                        pending
          .... ...1      BKIDEVRD       X'01' BKIDEVRD Virtual device is
                                        read only
0002    2 Bitstring    2 *              Reserved for IBM use
             BKIDBCCT indicates processes in HCPDBC.  It is used
             to indicate that outstanding i/o is being done
             maybe by the minidisk cache i/o handler.
             Thus BKIDBIRQ and BKIDBCCT BOTH must be 0 to indicate
             there is no outstanding Diag 250 for this device.
0004    4 Signed       4 BKIDBCCT       Count of processes in HCPDBC
0008    8 Signed       4 BKIDBIRQ       Chain of outstanding DBIRQs
000C   12 Signed       4 BKIDBCWK       Chain of outstanding i/o requests
0010   16 Signed       4 BKIBLKSZ       Block size of user's disk
0014   20 Signed       2 BKIVDEVN       Virtual device number
0016   22 Bitstring    2 *              Reserved for future IBM use
0018   24 Dbl-Word     8 BKIOFFCP       CP offset for disk
0020   32 Dbl-Word     8 BKIOFFST       User's requested offset
0028   40 Dbl-Word     8 BKISTART       User's starting block
0030   48 Dbl-Word     8 BKIEND         User's ending block
0038   56 Signed       4 BKIVDEVA       Virtual device block address
003C   60 Signed       4 BKIDINFO       Address of device information
0040   64 Signed       4 BKISVGBK       Caller's save block
0044   68 Signed       4 BKIRMVMD       Address of the VMDBK on which the
                                        RESET or REMOVE was issued.
0048   72 Dbl-Word     8 BKILOCK (3)    BKIBK lock
0060   96 Signed       4 *              Reserved for IBM use
0064  100 Signed       4 *              Reserved for IBM use
0068  104 Signed       4 *              Reserved for IBM Use
006C  108 Signed       4 *              Reserved for IBM use
          0000000E       BKISIZE        (*-BKIBK+7)/8 Length of BKIBK in
                                        DWs

 

BKIBK Storage Layout

          
*** BKIBK - Block I/O Block for DIAGNOSE X'250'
*
*     +------+------+-------------+---------------------------+
*   0 |:STAT |:FLAGS|/////////////|         BKIDBCCT          |
*     +------+------+-------------+---------------------------+
*   8 |         BKIDBIRQ          |         BKIDBCWK          |
*     +---------------------------+-------------+-------------+
*  10 |         BKIBLKSZ          |  BKIVDEVN   |/////////////|
*     +---------------------------+-------------+-------------+
*  18 |                       BKIOFFCP                        |
*     +-------------------------------------------------------+
*  20 |                       BKIOFFST                        |
*     +-------------------------------------------------------+
*  28 |                       BKISTART                        |
*     +-------------------------------------------------------+
*  30 |                        BKIEND                         |
*     +---------------------------+---------------------------+
*  38 |         BKIVDEVA          |         BKIDINFO          |
*     +---------------------------+---------------------------+
*  40 |         BKISVGBK          |         BKIRMVMD          |
*     +---------------------------+---------------------------+
*  48 |                                                       |
*     =                       BKILOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  60 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  68 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  70
*
*** BKIBK - Block I/O Block for DIAGNOSE X'250'

 

BKIBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
BKIBLKSZ       0010
BKIDBCCT       0004
BKIDBCWK       000C
BKIDBIRQ       0008
BKIDEVRD       0001 01
BKIDINFO       003C
BKIEND         0030
BKIFLAGS       0001
BKILOCK        0048
BKIOFFCP       0018
BKIOFFST       0020
BKIRELOC       0000 20
BKIRESET       0000 40
BKIRMPD        0001 04
BKIRMVMD       0044
BKISIZE        006C 0000000E
BKISTART       0028
BKISTAT        0000
BKISVGBK       0040
BKIVDEVA       0038
BKIVDEVN       0014

This information is based on z/VM V6R2.0. Last updated on 21 Nov 2011 at 10:54:01 EDT.
Copyright IBM Corporation, 1990, 2011