BELBK Back to Index page
 
Prolog 
Control Block Contents 
   BELBK 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.


  BELBK Prolog Top of page
 
 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 Top of page
 

 BELBK DSECT Top of page
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 Top of page
 
          
*** 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 Top of page
 
 
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 7.2.0 Last updated on 24 Jun 2020 at 09:27:04 EDT.
Copyright IBM Corporation, 1990, 2020