IBM: VDSBK

Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

VDSBK

Prolog

Control Block Contents

VDSBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

VDSBK Prolog

 NAME       : HCPVDSBK
 DESCRIPTION: VIRTUAL DEVICE SIMULATION BLOCK
 DSECT      : VDSBK
 FUNCTION   : THIS CONTROL BLOCK CONTAINS INFORMATION NECESSARY FOR
              SIMULATION OF A VIRTUAL DEVICE.
 LOCATED BY : VDEVVDS   FIELD OF HCPVDEV
 CREATED BY : HCPVDSDF - WHILE DEFINING A VIRTUAL DEVICE.
 DELETED BY : HCPVDBDL - WHEN DELETING A VIRTUAL DEVICE.

VDSBK Control Block Content


VDSBK DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      VDSBK          VIRTUAL DEVICE SIMULATION BLOCK
0000    0 Signed       4 VDSVFC         POINTER TO VFCBLOK
0004    4 Bitstring    4 VDSFLAGS (0)   DEVICE SIMULATION FLAGS
0004    4 Bitstring    1 VDSRFLG        DEVICE SIMULATION REQUEST FLAG
          1... ....      VDSATTN        X'80' CONS - 2 OR MORE ATTENTIONS
                                        SEEN
          .1.. ....      VDSDIAG        X'40' DIAGNOSE I/O ACTIVE ON THIS
                                        DEVICE
0005    5 Bitstring    1 VDSSFLG        DEVICE SIMULATION STATUS FLAG
          1... ....      VDSCCW1        X'80' PROCESSING FIRST CCW IN
                                        CHAIN
          .1.. ....      VDSCPOST       X'40' VIRTUAL COND. CODE
                                        PRESENTED
          ..1. ....      VDSLTIC        X'20' LAST CCW PROCESSED WAS A
                                        TIC
          ...1 ....      VDSDTRAN       X'10' DATA XFER IN THIS CCW
                                        STRING
          .... 1...      VDSFEED        X'08' RDR - LAST CCW DID A 'FEED'
          .... .1..      VDSCRCW        X'04' TIC SCAN PASSED CURR
                                        RCWTASK
          .... ..1.      VDSREJLT       X'02' PRESENT COMMAND REJECT
                                        LATER
          .... ...1      VDSUE          X'01' UNIT EXCEPTION HAS BEEN
                                        PRESENTED
0006    6 Bitstring    1 VDSCFLG        DEVICE SIMULATION CONTROL FLAG
          .... 1...      VDSAUCR        X'08' CONS - AUTO CR ON FIRST
                                        READ
0007    7 Bitstring    1 *              RESERVED FOR FUTURE IBM USE
0008    8 Signed       4 VDSRCW         POINTER TO CURRENT RCWTASK
000C   12 Signed       4 VDSGSDVC       POINTER TO WORK GSDBLOK
0010   16 Signed       4 VDSACCW        ADDRESS OF CURRENT CCW IN RCWTASK
0014   20 Signed       4 VDSUCSB        POINTER TO UCSB DATA BLOCK
0018   24 Signed       4 VDSGSDW        POINTER TO VSP WORK GSDBLOK
001C   28 Signed       4 VDSGSDI        POINTER TO INPUT GSDBLOK
0020   32 Signed       4 VDSGSDO        POINTER TO OUTPUT GSDBLOK
0024   36 Address      4 VDSSDL         POINTER TO AN SDLBK
          00000005       VDSSIZE        (*-VDSBK+7)/8 VDSBK SIZE IN
                                        DOUBLE-WORDS

VDSBK Storage Layout

*** VDSBK - VIRTUAL DEVICE SIMULATION BLOCK
*
*     +---------------------------+------+------+------+------+
*   0 |          VDSVFC           |:RFLG |:SFLG |:CFLG |//////|
*     +---------------------------+------+------+------+------+
*   8 |          VDSRCW           |         VDSGSDVC          |
*     +---------------------------+---------------------------+
*  10 |         VDSACCW           |         VDSUCSB           |
*     +---------------------------+---------------------------+
*  18 |         VDSGSDW           |         VDSGSDI           |
*     +---------------------------+---------------------------+
*  20 |         VDSGSDO           |          VDSSDL           |
*     +---------------------------+---------------------------+
*  28
*
*** VDSBK - VIRTUAL DEVICE SIMULATION BLOCK