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

ASTE

Prolog  

Control Block Contents  
   ASTE DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


ASTE Prolog

 Name       : HCPASTE
 Description: ASN-Second-Table Entry
 DSECT      : ASTE
 Function   : The ASTE maps the storage associated with one entry
              of an ASN-Second Table. The entry is used in ASN
              and AR translation, and is also used to access
              access other information associated with an address
              space.
              Notes      : In ESA/390, CR0.15 is the address space control
              bit.  If set the ASTE length is 64 bytes.
              Otherwise, the length is 16 bytes.  The
              first 16 bytes are mapped identically
              regardless of the length.
              Notes      : In ESAME, all ASTEs are 64 bytes in length,
              CR0.15 does not apply.  However, the ESAME ASTE
              is slightly different than the ESA/390 ASTE.
              In the ESAME build of CP, we need both the
              ESAME ASTE mapping (for host ASTEs and ESAME
              guest ASTEs) and the ESA/390 ASTE mapping (for
              ESA/390 guest ASTEs).  Since most of the ASTE
              definition is identical for both ASTE formats,
              the entire definition is not duplicated.
              Instead, only the 3 words ( words 2, 3 and 6 )
              which differ between the two formats are
              defined separately.
 Located by : ASN and AR translation
              ASTEs for address spaces built by CP are located by
              the ASCASTE pointer of the associated ASCBK.
              An ASTE is part of an ASN second table (AST). The
              beginning of the table is pointed to by:
              - An ASN first table entry (AFTE)
              The AST is indexed into by an ASN second index (ASX).
              An ASTE may be directly pointed to by:
              - An access list entry (ALE)
              - CR5 (when the ASTE is the primary ASTE)
              - An entry table entry (ETE)
              There is also an ASTE within MWBK.
 Created by : ASTEs for address spaces built by CP are
              initialized by HCPASMCR, though the storage
              is managed by HCPVCB.
              Within MWBK: HCPMWPBL - MAS work area build
              The ASTE is also used to map guest ASN Second Table
              Entries in guest storage.
 Deleted by : Once storage has been allocated as an ASTE for an
              address space built by CP, it can never be used for
              anything else.  Though it may no longer represent an
              ASTE for an active address space (HCPASMDS "destroys"
              a space), the ASTE itself will be held in reserve
              until it can be given out again as an ASTE (with a
              different ASTE sequence number).  The popular phrase
              is "ASTEs are forever".
              Within MWBK: HCPMWPDL - MAS work area delete
 Serialized : ASTEs for address spaces built by CP are generally
              serialized by the ASCBK lock in the associated ASCBK.
              Addtionally, for V=V guests, the fields ASTSTD (390
              build only) and ASTASCE (ESAME build only) are
              serialized by the owning virtual configuration's
              VMDPTIL (in the base VMDBK) held exclusive (to
              change).
              The ASTALD field is serialized by the ALCBK lock in
              ALCBK associated with the access list, if there is a
              primary-space access list.
              Within MWBK: See MWBK prologue.
              When used to map guest storage, the user of the
              DSECT is responsible for serialization.

 

ASTE Control Block Content


ASTE DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      ASTE           ASN-Second-Table Entry
          00000010       ASTBSALG       16 Basic ASTE must be aligned on
                                        16-byte boundary.
          00000040       ASTEXALG       64 Extended ASTE must be aligned
                                        on 64-byte boundary.
0000    0 Bitstring   64 * (0)
0000    0 Bitstring   16 ASTBASI (0)
0000    0 Signed       4 ASTW0 (0)      Word 0 of the ASTE
          000ASTW0       ASTATOM        X'7FFFFFFC' Authority table
                                        origin in word 0
0000    0 Signed       4 ASTATO         Authority-Table Origin
0004    4 Signed       4 ASTW1 (0)      Word 1 of the ASTE
          000ASTW1       ASTATLM        X'0000FFF0' Authority table
                                        length in word 1
0004    4 Signed       2 ASTAX          Authorization Index
0006    6 Signed       2 ASTATL         Authority Table Length
     Bits 64 through 127 of the ASTE are defined differently for ESA/390
     ASTEs than for ESAME ASTEs. For the 390 build of CP, we only need the
     390 definition (obviously). However, for the ESAME build of CP, we need
     *BOTH* the 390 and ESAME definitions, with different names, to be able
     to handle both 390 and ESAME guests.
     ESA/390 ASTE bits 64 through 127: - Bits 64 through 95 contain the
     ESA/390 STD - Bits 96 through 127 contain the LTD
0008    8 Signed       4 ASTSTD         ESA/390 ASTE Segment-Table
                                        Designation
000C   12 Signed       4 ASTLTD         ESA/390 ASTE Linkage-Table
                                        Designation
0008    8 Bitstring    1 ASTSTDB0       Byte 0
          1... ....      ASTSTDSS       X'80' Space-Switch-Event Control
0009    9 Bitstring    3 *              Bytes 1-3
000C   12 Bitstring    1 ASTLTDB0       Byte 0
          1... ....      ASTLTDSL       X'80' Subsystem-Linkage Control
000D   13 Bitstring    3 *              Bytes 1-3 .*
                                        .********************************
                                        ***************************** .*
                                        ESAME ASTE bits 64 through 127
                                        .********************************
                                        ***************************** .*
                                        .*
0010   16 Signed       4 ASTALD         Access-List Designation
0014   20 Signed       4 ASTSN          ASTE Sequence Number
          .... ....      ASTSNJM        X'80000000' J-bit. When this bit
                                        is set in ASTEs built by CP, the
                                        ASTE is in a state of flux. This
                                        bit is set to force sequence
                                        number mismatches by ART and
                                        i-ASIT certification.
          000ASTSN       ASTSNMAX       X'7FFFFFFF'-1000 Maximum sequence
                                        ASTSN value. Free storage will no
                                        longer give out an ASTE when
                                        ASTSN exceeds this value.
     Bits 192 through 223 of the ASTE are defined differently for ESA/390
     ASTEs than for ESAME ASTEs:
     * ************************************************************* *
     ESA/390 ASTE bits 192 through 223 *
     ************************************************************* * *
     ESA/390 ASTE bits 192 through 223 are reserved.
0018   24 Signed       4 *              Reserved for IBM use .* .*
001C   28 Signed       4 ASTPRGM (0)    Reserved for use by programming
                                        Note: The storage for some ASTEs
                                        is obtained/released by the
                                        verifiable control block manager.
                                        It uses this field to chain
                                        inactive ASTEs together. Bit zero
                                        indicates whether the block is
                                        active (0) or inactive (1).
001C   28 Bitstring    1 ASTSTAT        Status of this ASTE (bit 0 only)
          1... ....      ASTINACT       X'80' This ASTE is inactive
001D   29 Bitstring    1 * (3)          Place holder
     End of the architected ASTE field definitions.
     The following field definitions map the CP usage area in the second 32
     bytes of the architected ASTE definition. These bytes are architected
     as "reserved for possible future extensions and should contain all
     zeros", but are not checked for zeros in current implementations. They
     are not technically available for programming (that is, CP) use, but we
     use them anyway, since it's not enforced.
0020   32 Dbl-Word     8 ASTEID (0)     ASTE identifier In CP usage, this
                                        is an e-ASIT.
0020   32 Dbl-Word     8 ASTEASIT (0)   CP usage: ASTE e-ASIT.
0020   32 Signed       4 ASTEID1 (0)    ASTE identifier, word 1. In CP
                                        usage, this is the ASTE origin.
0020   32 Signed       4 ASTASTEO       CP usage: ASTE origin.
0024   36 Signed       4 ASTEID2 (0)    ASTE identifier, word 2. In CP
                                        usage, this is the space creation
                                        sequence number.
0024   36 Signed       4 ASTSCRSN       CP usage: ASTE space creation
                                        sequence number.
0028   40 Bitstring   24 *              Reserved for IBM use
          00000040       ASTLEN         *-ASTE Entry size in bytes
          00000002       ASTBSIZE       (ASTBLEN+7)/8 Size in doublewords
                                        of the ASTBASI
          00000008       ASTSIZE        (ASTLEN+7)/8 Size in doublewords
                                        of the ASTE
     ASTE Redefinition areas
0000    0 Bitstring    1 ASTATOB0       Byte 0
          1... ....      ASTINV         X'80' ASX-invalid bit, Address
                                        space is not available
0001    1 Bitstring    2 *              Bits 8 through 23
0003    3 Bitstring    1 ASTATOB3       Byte 3
          .... ..11      ASTAT370       X'03' Bits must be zero
0006    6 Bitstring    1 *              Bits 0 through 7
0007    7 Bitstring    1 ASTATLB1       Byte 1
          .... 1111      ASTATLZ        X'0F' Bits must be zero
     Note : An active ASTE should always have bit zero = 0. Do NOT change
     bit zero of ASTASCBK. See ASTPRGM for more details.
001C   28 Address      4 ASTASCBK       Address of ASCBK in ASTEs built
                                        by CP.

 

ASTE Storage Layout

          
*** ASTE - ASN-Second-Table Entry
*
*     +---------------------------+-------------+-------------+
*   0 |          ASTATO           |   ASTAX     |   ASTATL    |
*     +---------------------------+-------------+-------------+
*   8 |          ASTSTD           |          ASTLTD           |
*     +---------------------------+---------------------------+
*  10
*
*** ASTE - ASN-Second-Table Entry
          
*** Overlay for ASTSTD in ASTE
*
*     +------+--------------------+
*   8 |:STDB0|////////////////////| C
*     +------+--------------------+
*
*** Overlay for ASTSTD in ASTE
          
*** Overlay for ASTLTD in ASTE
*
*                                 +------+--------------------+
*   8 ...                       C |:LTDB0|////////////////////|
*     +---------------------------+------+--------------------+
*  10 |          ASTALD           |          ASTSN            |
*     +---------------------------+------+--------------------+
*  18 |///////////////////////////|:STAT |////////////////////|
*     +---------------------------+------+--------------------+
*  20 |         ASTASTEO          |         ASTSCRSN          |
*     +---------------------------+---------------------------+
*  28 |///////////////////////////////////////////////////////|
*     =///////////////////////////////////////////////////////=
*     |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
*  40
*
*** Overlay for ASTLTD in ASTE
          
*** Overlay for ASTATO in ASTE
*
*     +------+-------------+------+
*   0 |:ATOB0|/////////////|:ATOB3| 4
*     +------+-------------+------+
*
*** Overlay for ASTATO in ASTE
          
*** Overlay for ASTATL in ASTE
*
*                                               +------+------+
*   0 ...                                     6 |//////|:ATLB1|
*                                               +------+------+
*   8
*
*** Overlay for ASTATL in ASTE
          
*** Overlay for ASTPRGM in ASTE
*
*                                 +---------------------------+
*  18 ...                      1C |         ASTASCBK          |
*                                 +---------------------------+
*  20
*
*** Overlay for ASTPRGM in ASTE

 

ASTE Cross Reference

Symbol         Dspl Value
-------------- ---- -----
ASTALD         0010
ASTASCBK       001C
ASTASTEO       0020
ASTATL         0006
ASTATLB1       0007
ASTATLM        0004 000ASTW1
ASTATLZ        0007 0F
ASTATO         0000
ASTATOB0       0000
ASTATOB3       0003
ASTATOM        0000 000ASTW0
ASTAT370       0003 03
ASTAX          0004
ASTBASI        0000
ASTBSALG       0000 00000010
ASTBSIZE       0028 00000002
ASTEASIT       0020
ASTEID         0020
ASTEID1        0020
ASTEID2        0024
ASTEXALG       0000 00000040
ASTINACT       001C 80
ASTINV         0000 80
ASTLEN         0028 00000040
ASTLTD         000C
ASTLTDB0       000C
ASTLTDSL       000C 80
ASTPRGM        001C
ASTSCRSN       0024
ASTSIZE        0028 00000008
ASTSN          0014
ASTSNJM        0014 00
ASTSNMAX       0014 000ASTSN
ASTSTAT        001C
ASTSTD         0008
ASTSTDB0       0008
ASTSTDSS       0008 80
ASTW0          0000
ASTW1          0004

This information is based on z/VM V4R1.0.
Last updated on 5 Jun 2001 at 12:57:57 EDT.
Copyright IBM Corporation, 1990, 2001