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
              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 z/Arch, all ASTEs are 64 bytes in length,
              CR0.15 does not apply. However, the z/Arch ASTE
              is slightly different from the ESA/390 ASTE.
              We need both the
              z/Arch ASTE mapping (for host ASTEs and z/Arch
              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, ASTASCE is
              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' ASTATOM 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' ASTATLM Authority
                                        table length in word 1
0004    4 Signed       2 ASTAX          Authorization Index
0006    6 Signed       2 ASTATL (0)     Authority Table Length
0006    6 Bitstring    1 ASTATL_0       Byte 0
0007    7 Bitstring    1 ASTATL_1       Byte 1
          .... ..1.      ASTCA          X'02' ASTCA Controlled ASN
                                        (ESAME)
          .... ...1      ASTRA          X'01' ASTRA Reusable ASN (ESAME)
      Bits 64 through 127 of the ASTE are defined differently
      for ESA/390 ASTEs than for z/Arch ASTEs.
      We need *BOTH* the
      390 and z/Arch definitions, with different names, to be
      able to handle both 390 and z/Arch 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' ASTSTDSS Space-Switch-Event
                                        Control
0009    9 Bitstring    3 *              Bytes 1-3
000C   12 Bitstring    1 ASTLTDB0       Byte 0
          1... ....      ASTLTDSL       X'80' ASTLTDSL Subsystem-Linkage
                                        Control
000D   13 Bitstring    3 *              Bytes 1-3
     * z/Arch ASTE bits 64 through 127
      z/Arch ASTE bits 64 through 127 contain the 64-bit ASCE
      (Address-Space-Control Element), which has either an RTD
      (Region-Table Designation) or a z/Arch STD.  The z/Arch
      ASTE LTD is moved to bits 192-223.
0008    8 Dbl-Word     8 ASTASCE        z/Arch ASTE Address-Space-
                                        Control Element
0008    8 Signed       4 ASTASCE0       Word 0 of z/Arch ASTE ASCE
000C   12 Signed       4 ASTASCE1       Word 1 of z/Arch ASTE ASCE
0010   16 Signed       4 ASTALD         Access-List Designation
0014   20 Signed       4 ASTSN          ASTE Sequence Number
          .... ....      ASTSNJM        X'80000000' ASTSNJM 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 ASTSNMAX 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 z/Arch ASTEs:
      ESAME ASTE bits 192 through 223 contain the LTD or LFTD.
0018   24 Signed       4 ASTGLTD        z/Arch ASTE Linkage-Table
                                        Designation if ASN-and-LX-Reuse
                                        is not enabled
0018   24 Signed       4 ASTGLFTD       ESAME ASTE Linkage-First-Table
                                        Designation if ASN-and-LX-Reuse
                                        is enabled
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' ASTINACT This ASTE is
                                        inactive
001D   29 Bitstring    1 * (3)          Place holder
      The following field definitions map the CP usage area
      in the next 8 bytes of the architected ASTE definition.
      These bytes are architected as "Available for programming".
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.
      When ASN-and-LX-Reuse is enabled,
      ESAME bytes 44-47 contain the ASTE Instance Number.
0028   40 Bitstring    4 *              Reserved for IBM use
002C   44 Signed       4 ASTIN          ASTE Instance Number Used during
                                        ASN translation when
                                        ASN-and-LX-Reuse facility is
                                        enabled (z/Arch guest). Reserved
                                        for IBM use (390 guest).
0030   48 Bitstring   16 *              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' ASTINV 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' ASTAT370 Bits must be zero
0006    6 Bitstring    1 *              Bits 0 through 7
0007    7 Bitstring    1 ASTATLB1       Byte 1
          .... 1111      ASTATLZ        X'0F' ASTATLZ 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     |:ATL_0|:ATL_1|
*     +---------------------------+-------------+------+------+
*   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
*
*** Overlay for ASTLTD in ASTE
          
*** Overlay for ASTSTD in ASTE
*
*     +-------------------------------------------------------+
*   8 |                       ASTASCE                         |
*     +-------------------------------------------------------+
*  10
*
*** Overlay for ASTSTD in ASTE
          
*** Overlay for ASTASCE in ASTE
*
*     +---------------------------+---------------------------+
*   8 |         ASTASCE0          |         ASTASCE1          |
*     +---------------------------+---------------------------+
*  10 |          ASTALD           |          ASTSN            |
*     +---------------------------+---------------------------+
*  18 |         ASTGLTD           | 1C
*     +---------------------------+
*
*** Overlay for ASTASCE in ASTE
          
*** Overlay for ASTGLTD in ASTE
*
*     +---------------------------+------+--------------------+
*  18 |         ASTGLFTD          |:STAT |////////////////////|
*     +---------------------------+------+--------------------+
*  20 |         ASTASTEO          |         ASTSCRSN          |
*     +---------------------------+---------------------------+
*  28 |///////////////////////////|          ASTIN            |
*     +---------------------------+---------------------------+
*  30 |///////////////////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
*  40
*
*** Overlay for ASTGLTD 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
ASTASCE        0008
ASTASCE0       0008
ASTASCE1       000C
ASTASTEO       0020
ASTATL         0006
ASTATL_0       0006
ASTATL_1       0007
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       0030 00000002
ASTCA          0007 02
ASTEASIT       0020
ASTEID         0020
ASTEID1        0020
ASTEID2        0024
ASTEXALG       0000 00000040
ASTGLFTD       0018
ASTGLTD        0018
ASTIN          002C
ASTINACT       001C 80
ASTINV         0000 80
ASTLEN         0030 00000040
ASTLTD         000C
ASTLTDB0       000C
ASTLTDSL       000C 80
ASTPRGM        001C
ASTRA          0007 01
ASTSCRSN       0024
ASTSIZE        0030 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 V5R3.0. Last updated on 25 Jun 2007 at 15:59:30 EDT.
Copyright IBM Corporation, 1990, 2007