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

#### AMSG

Prolog

Control Block Contents
AMSG DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### AMSG Prolog

     NAME       : HCPAMSG
     DESCRIPTION: Asynchronous Event Message
     DSECT      : AMSG
     FUNCTION   : Preserve a Delayed Response Message until retrieved by
                  requestor.
     LOCATED BY : Pointer (VDEVAEVT) in the Virtual Device Block
                  Pointer (VDEVREVT) in the Virtual Device Block
                  Pointer (SCTMFPT/SCTMLPT) in CFLF Subsystem
                  Connect Table (See NOTES below).
     CREATED BY : HCPSVIAP - Delayed Response Message Routing.
                  HCPLFPSF - CFLF Perform Subsystem Function CCW
                  Simulation (See NOTES below).
     DELETED BY : HCPAEPPD - Purge all outstanding AEBK, AMSG and IOCM blocks
                  for the Virtual Device.
                  HCPAEPRD - Retrieve Delayed Response Message (CCW SIMULATION)
                  HCPLFSIM - CFLF Read Subsystem Data CCW simulation
                  (See NOTES below).
     NOTES      : This block is also used by the CFLF simulation
                  support. In thi case the Asynchronous Message block
                  is allocated and returned either Synchronously or
                  Asynchronously to a CFLF user during Read Subsystem
                  Data CCW simulation.

#### AMSG Control Block Content

#### AMSG DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      AMSG           Asynchronous Event Message
    0000    0 Bitstring   24 AMSGHDR (0)    Header record
    0000    0 Address      4 AMSGNEXT       Pointer to next AMSG block NOTE:
                                            must be at the same offset as
                                            IOCMNEXT in the HCPIOCM block.
    0004    4 Character    4 AMSGBKID       Identifies storage area as an
                                            AMSG block. NOTE: must be at the
                                            same offset as IOCMBKID in the
                                            HCPIOCM block.
    0008    8 Signed       4 AMSGTLG        Length of the entire message
                                            Block in BYTES = Header
                                            Length(AMSGHDRL) + Content
                                            Length.
    000C   12 Signed       4 AMSGMGID       Message ID
    0010   16 Signed       2 AMSGLGH        Length of the message
    0012   18 Bitstring    1 AMSGEVST       Asynchronous Event status NOTES :
                                            There is not a strict
                                            relationship between this status
                                            and DRM status.
              00000001       AMSGNOEV       X'01' AMSGNOEV Event does not
                                            exist at device.
              00000002       AMSGPNEV       X'02' AMSGPNEV Event pending
                                            completion in the device.
              00000004       AMSGCPEV       X'04' AMSGCPEV Event completed at
                                            the device.
    0013   19 Bitstring    1 AMSGSESS       Session ID
    0014   20 Character    4 *              Reserved for future IBM use
              00000018       AMSGHDRL       *-AMSGNEXT Length of Header in
                                            bytes
    0018   24 Bitstring    1 AMSGBUF (0)    Message buffer contents -
                                            Variable length data. See HCPDMSG
                                            for an overlay of the AMSGBUF
                                            field.
              0000021C       AMSGMAXB       540 Maximum number of bytes of
                                            storage needed for the
                                            Asynchronous Message Buffer. Code
                                            defined for Setting/Testing
                                            AMSGBKID
              00D4E2C7       AMSGID         C'AMSG' Used to set block
                                            identifier

#### AMSG Storage Layout

    *** AMSG - Asynchronous Event Message
    *
    *     +---------------------------+---------------------------+
    *   0 |         AMSGNEXT          |         AMSGBKID          |
    *     +---------------------------+---------------------------+
    *   8 |         AMSGTLG           |         AMSGMGID          |
    *     +-------------+------+------+---------------------------+
    *  10 |  AMSGLGH    |:GEVST|:GSESS|///////////////////////////|
    *     +-------------+------+------+---------------------------+
    *
    *** AMSG - Asynchronous Event Message

#### AMSG Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    AMSGBKID       0004
    AMSGBUF        0018
    AMSGCPEV       0012 00000004
    AMSGEVST       0012
    AMSGHDR        0000
    AMSGHDRL       0014 00000018
    AMSGID         0018 00D4E2C7
    AMSGLGH        0010
    AMSGMAXB       0018 0000021C
    AMSGMGID       000C
    AMSGNEXT       0000
    AMSGNOEV       0012 00000001
    AMSGPNEV       0012 00000002
    AMSGSESS       0013
    AMSGTLG        0008

This information is based on z/VM V6R1.0. Last updated on 18 Feb 2010 at 08:23:16 EDT.
Copyright IBM Corporation, 1990, 2008