ASTE Back to Index page
 
Prolog 
Control Block Contents 
   ASTE DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  ASTE Prolog Top of page
 
 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.
 RELOCATION CONSIDERATIONS : None
 
 
  ASTE Control Block Content Top of page
 

 ASTE DSECT Top of page
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 Top of page
 
          
*** 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 Top of page
 
 
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 7.3.0 Last updated on 22 Jun 2022 at 15:47:31 EDT.
Copyright IBM Corporation, 1990, 2022