BPLBK Back to Index page
 
Prolog 
Control Block Contents 
   BPLBK 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.


  BPLBK Prolog Top of page
 
 NAME       : HCPBPLBK
 DESCRIPTION: *BLOCKIO parameter list dsect
 DSECT      : BPLBK
 FUNCTION   : This DSECT maps the input parameter list sent
              by the guest to CP when the guest requests a
              multiple block I/O operation from *BLOCKIO
 LOCATED BY : SNDPLADR in SNDBK
 CREATED BY : HCPBIMMS (who copies the guest's parameter
              list into host storage)
 DELETED BY : HCPBIMMS
 SERIALIZED : Unique task execution
              VMDBK dispatch lock.
              BLOCKIO lock
 RELOCATION CONSIDERATIONS : None
 NOTES      : When the guest sends the address in guest storage
              of this parameter list, it may not be word-aligned.
              This DSECT assumes that before any fields are
              referenced, the parameter list has been moved into
              host storage and been word-aligned.  References
              to address fields will cause an exception if this
              is not the case.
 
 
  BPLBK Control Block Content Top of page
 

 BPLBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure BPLBK *BLOCKIO parameter list dsect 0000 0 Signed 4 * (0) 0000 0 Bitstring 1 BPLRQCOD Request code 00000001 BPLWRITE X'01' BPLWRITE Write request 00000002 BPLREAD X'02' BPLREAD Read request 0001 1 Bitstring 1 BPLRETCD Return code for this operation 0002 2 Bitstring 2 * Reserved for IBM use 0004 4 Address 4 BPLBUFAD Guest real address of data buffer 0008 8 Signed 4 BPLBKNUM Block number. Signed value; may be negative. 000C 12 Signed 4 * Reserved for IBM use 0010 16 Signed 4 BPLNXENT (0) Next entry in p-list starts here 00000002 BPLSIZE (*-BPLBK+7)/8 Size, in doublewords, of BPLBK
 
 
  BPLBK Storage Layout Top of page
 
          
*** BPLBK - *BLOCKIO parameter list dsect
*
*     +------+------+-------------+---------------------------+
*   0 |:RQCOD|:RETCD|/////////////|         BPLBUFAD          |
*     +------+------+-------------+---------------------------+
*   8 |         BPLBKNUM          |///////////////////////////|
*     +---------------------------+---------------------------+
*
*** BPLBK - *BLOCKIO parameter list dsect
 
 
  BPLBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
BPLBKNUM       0008
BPLBUFAD       0004
BPLNXENT       0010
BPLREAD        0000 00000002
BPLRETCD       0001
BPLRQCOD       0000
BPLSIZE        0010 00000002
BPLWRITE       0000 00000001
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:47:47 EDT.
Copyright IBM Corporation, 1990, 2022