IBM: QDIO

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.

QDIO

Prolog

Control Block Contents

QDIO DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

QDIO Prolog

 NAME       : HCPQDIO
 STATUS     : VM/ESA Version 2, Release 4.0
 DESCRIPTION: Queued Direct I/O Control Block
 DSECT      : QDIO
 FUNCTION   :
              HCPQDIO maps all the guest's and associated CP shadow
              QDIO Queues for a specific subchannel.
 LOCATED BY : VDEVQDIO
 SERIALIZED : VDEV Lock
 CREATED BY : Dynamically created by HCPGETST when a QDIO
              Queue is created with an Establish-QDIO-
              Queues Channel Command.
 DELETED BY : Deleted by HCPRELST when a QDIO Activate-
              QDIO-Queues Channel Command terminates.

QDIO Control Block Content


QDIO DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      QDIO           Queued Direct I/O Control Block
0000    0 Dbl-Word     8 QDIOLOCK (3)   QDIO Lock Word
0018   24 Address      4 QDIORDEV       RDEV associated with this queue
001C   28 Signed       4 QDIOREAS       Failing reason code during QDIO
                                        Queue creation.
0020   32 Address      4 QDICPQDR       Address of CP's Queue-Description
                                        Record (QDR).
     Following Fields Serialized on Compare and Swap
0024   36 Address      4 QDIOQERR       Specifies a QIOBK that has an
                                        error to report.
     -----End of Compare and Swap Serialization***************----
     QDIO Queue Information Block
0028   40 Address      4 QDIGQIB        Guest absolute address of QIB
002C   44 Address      4 QDIHQIB        Host absolute address of QIB
0030   48 Bitstring    1 QDIOFG1        Storage Access Flag
          1111 ....      QDIQKEY        X'F0' Storage Key Mask for QIB
          .... 1...      QDIOACT        X'08' QDIO Q's have been
                                        activated
          .... .1..      QDIODOFS       X'04' Delete QDIO Queues when
                                        final status is received.
0031   49 Bitstring    1 * (3)          Reserved for future IBM use
     Input / Output QDIO Queues
0034   52 Bitstring    1 QDIOFMT        QDIO Format Type
0035   53 Bitstring    1 QDINPCT        Number of Input Queues
0036   54 Bitstring    1 QDIOUTCT       Number of Output Queues
0037   55 Bitstring    1 QDIOHWS        Hardware Support Flags
          1... ....      QDISIGAW       X'80' SIGA-w Initiate Write
                                        Supported
          .1.. ....      QDISIGAR       X'40' SIGA-r Initiate Read
                                        Supported
          ..1. ....      QDISIGAS       X'20' SIGA-s Synchronize
                                        Supported
0038   56 Address      4 QDINPUT        Pointer to a link list of QIOBKs
                                        for all Input Queues
003C   60 Address      4 QDIOUTQ        Pointer to a link list of QIOBKs
                                        for all Output Queues
0040   64 Signed       4 *              Reserved for future IBM use
0044   68 Signed       4 *              Reserved for future IBM use
0048   72 Character    1 QDI$END (0)    End of Queued Direct I/O CB
     Notes : The following assembler equates are defined and can be used but
     do not appear in the control block expansion because they the PLX
     section and PRINT OFF,NOGEN is in effect.
     QDISZB EQU (QDI$END-QDIO) Size in bytes QDISZ EQU (QDI$END-QDIO+7)/8
     Size in d-words

QDIO Storage Layout

*** QDIO - Queued Direct I/O Control Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       QDIOLOCK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  18 |         QDIORDEV          |         QDIOREAS          |
*     +---------------------------+---------------------------+
*  20 |         QDICPQDR          |         QDIOQERR          |
*     +---------------------------+---------------------------+
*  28 |         QDIGQIB           |         QDIHQIB           |
*     +------+--------------------+------+------+------+------+
*  30 |:OFG1 |////////////////////|:OFMT |:NPCT |:OUTCT|:OHWS |
*     +------+--------------------+------+------+------+------+
*  38 |         QDINPUT           |         QDIOUTQ           |
*     +---------------------------+---------------------------+
*  40 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  48 |                                                       |
*     =                       QDI$END                         =
*     |                                                       |
*     +-------------------------------------------------------+
*
*** QDIO - Queued Direct I/O Control Block