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

BELBK

Prolog  

Control Block Contents  
   BELBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


BELBK Prolog

 NAME       : HCPBELBK
 DESCRIPTION: Block I/O entry list
 DSECT      : BELBK
 FUNCTION   : This DSECT maps the input parameter list sent
              by the guest to CP when the guest requests
              an I/O operation via DIAGNOSE X'250'.
 LOCATED BY : BRQBELBK in the BRQBK
 CREATED BY : HCPBIDRW (who copies the guest's parameter
              list into host storage)
 DELETED BY : HCPBIDRW, for synchronous requests
              HCPBIDRW. for asynchronous requests
              satisfied synchronously
              HCPBIRIN, for asynchronous requests
              satisfied asynchronously
 SERIALIZED : Instruction stream serialization
 RELOCATION CONSIDERATIONS : None
 COMMENTS   :
              This parameter list may not be word-aligned in
              guest storage. However, this DSECT assumes that
              before any fields are referenced, the parameter
              list has been moved into host storage and
              word-aligned. References to fields in this block
              will cause an exception if this is not the case.
              There is one entry within the block I/O entry list
              for each read/write request.
              This control block is a GPI, and should
              not be changed incompatibly.

 

BELBK Control Block Content


BELBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BELBK          Block I/O entry list
0000    0 Signed       4 * (0)
0000    0 Bitstring    1 BELRQTYP       Type of operation being
                                        requested.
          00000001       BELWRITE       X'01' BELWRITE Write operation
                                        requested
          00000002       BELREAD        X'02' BELREAD Read operation
                                        requested
0001    1 Bitstring    1 BELSTAT        Status code for this operation
          00000000       BELOK          X'00' BELOK The read or write
                                        operation was successful
          00000001       BELINVBK       X'01' BELINVBK Invalid block
                                        number specified
          00000002       BELADDRE       X'02' BELADDRE Addressing
                                        exception condition
          00000003       BELRODEV       X'03' BELRODEV A write operation
                                        was requested to a read-only
                                        device
          00000004       BELINVSZ       X'04' BELINVSZ Block size does
                                        not match that of the virtual
                                        device
          00000005       BELIOERR       X'05' BELIOERR Unrecoverable I/O
                                        error
          00000006       BELBADRQ       X'06' BELBADRQ Request type is
                                        not read or write
          00000007       BELPROTE       X'07' BELPROTE Protection
                                        exception condition
          00000008       BELADCPE       X'08' BELADCPE
                                        Addressing-capability exception
                                        condition
          00000009       BELALTRE       X'09' BELALTRE ALEN-translation
                                        exception condition
          0000000A       BELALSPE       X'0A' BELALSPE ALET-specification
                                        exception condition
          0000000B       BELSPECE       X'0B' BELSPECE Specification
                                        exception condition
          0000000C       BELNOTPR       X'0C' BELNOTPR This block I/O
                                        entry was not processed
0002    2 Bitstring    2 BELRSD01       Reserved for IBM use
      Format of remainder of block when BIO64BIT = 0 in the BIOPL.
0004    4 Signed       4 BELBKNUM       32 bit block number
0008    8 Address      4 BELBALET       ALET of guest data buffer
000C   12 Address      4 BELBUFAD       31 bit guest absolute address of
                                        the data buffer.
0010   16 Signed       4 BELNEXT (0)    Start of next entry in p-list
          00000002       BELSIZE        (*-BELBK+7)/8 Size of one entry
                                        of the BELBK in doublewords
      Format of remainder of block when BIO64BIT = 1 in the BIOPL.
0004    4 Address      4 BELBALETF1     ALET of guest data buffer
0008    8 Dbl-Word     8 BELBKNUM64     64 bit block number
0010   16 Address      8 BELBUFAD64     64 bit guest absolute address of
                                        the data buffer.
0018   24 Signed       4 BELNEXTF1 (0)  Start of next entry in p-list
          00000003       BELSIZEF1      (*-BELBK+7)/8 Size of one entry
                                        of the BELBK in doublewords

 

BELBK Storage Layout

          
*** BELBK - Block I/O entry list
*
*     +------+------+-------------+---------------------------+
*   0 |:RQTYP|:STAT |  BELRSD01   |         BELBKNUM          |
*     +------+------+-------------+---------------------------+
*   8 |         BELBALET          |         BELBUFAD          |
*     +---------------------------+---------------------------+
*
*** BELBK - Block I/O entry list
          
*** Overlay for BELBKNUM in BELBK
*
*                                 +---------------------------+
*   0 ...                       4 |        BELBALETF1         |
*     +---------------------------+---------------------------+
*   8 |                      BELBKNUM64                       |
*     +-------------------------------------------------------+
*  10 |                      BELBUFAD64                       |
*     +-------------------------------------------------------+
*
*** Overlay for BELBKNUM in BELBK

 

BELBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
BELADCPE       0001 00000008
BELADDRE       0001 00000002
BELALSPE       0001 0000000A
BELALTRE       0001 00000009
BELBADRQ       0001 00000006
BELBALET       0008
BELBALETF1     0004
BELBKNUM       0004
BELBKNUM64     0008
BELBUFAD       000C
BELBUFAD64     0010
BELINVBK       0001 00000001
BELINVSZ       0001 00000004
BELIOERR       0001 00000005
BELNEXT        0010
BELNEXTF1      0018
BELNOTPR       0001 0000000C
BELOK          0001 00000000
BELPROTE       0001 00000007
BELREAD        0000 00000002
BELRODEV       0001 00000003
BELRQTYP       0000
BELRSD01       0002
BELSIZE        0010 00000002
BELSIZEF1      0018 00000003
BELSPECE       0001 0000000B
BELSTAT        0001
BELWRITE       0000 00000001

This information is based on z/VM V6R2.0. Last updated on 21 Nov 2011 at 10:53:56 EDT.
Copyright IBM Corporation, 1990, 2011