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



Control Block Contents  

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

ALEBK Prolog

 Name       : HCPALEBK
 Description: Access List Entry
 Function   : ALEBK maps the storage associated with one entry
              of an Access List.  The entries are used in
              access register translation.
 Located by : Access register translation.
              An Access List Entry is part of an Access List Entry
              Table. The beginning of the table is pointed to by
              an entry in the Dispatchable Unit Control Table
              (DUCT) or by the primary ASN Second Table Entry
              (ASTE).  The access list entry table is indexed into
              by an access list entry number (ALETEN).
 Created by : ALEs designating entries in access lists created and
              managed by CP are formed by HCPALMAD.
 Deleted by : ALEs designating entries in access lists created and
              managed by CP are deleted by HCPALMDL.
 Serialized : This DSECT is to map guest storage, the user of
              the DSECT is responsible for serialization.
              It also maps ALEs in access lists created and managed
              by CP.  The ALCBK lock (ALCLOCK) is the serialization
              for changes to those entries.


ALEBK Control Block Content


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      ALEBK          Access List Entry
0000    0 Bitstring   16 ALE (0)
0000    0 Signed       4 ALEW0 (0)      The first word of the ALEBK
          .... ....      ALEW0INV       X'80000000' Invalid bit in ALE
                                        word 0
          000ALEW0       ALEW0SNM       X'00FF0000' ALE sequence number
                                        in word 0
          000ALEW0       ALEW0SIG       X'83FFFFFF' Defined bits in ALE
                                        word 0
0000    0 Bitstring    1 ALE0           First byte of entry
          1... ....      ALEINV         X'80' Access List Entry INValid
                                        bit - '1'B = the access-list
                                        entry is invalid. During AR
                                        translation involving this ALE,
                                        an ALEN-translation exception is
          .... ..1.      ALEFONLY       X'02' Fetch only bit - indicates
                                        fetch only access to address
          .... ...1      ALEPRIV        X'01' PRIVate Bit - '0'B = any
                                        program can use this entry. '1'B
                                        = programs must have an EAX (in
                                        CR8) which is identical to ALEAX,
                                        or the EAX (in CR8) must select
                                        an authority table secondary bit
                                        with a value of 1.
0001    1 Bitstring    1 ALESN          ALE Sequence Number - is compared
                                        against the ALETSN in the ALET
                                        during access-register
                                        translation. Inequality causes an
                                        ALE-sequence exception to be
0002    2 Signed       2 ALEAX          ALE Authorization IndeX - may be
                                        used to determine whether the
                                        program for which AR translation
                                        is being performed is authorized
                                        to use the access-list entry. See
                                        ALEPRIV for more info.
0004    4 Bitstring    4 *              Reserved Bits 0 and 28-30 of the
                                        following field must be zeros.
0008    8 Address      4 ALEASTE (0)    ASN Second Table Entry origin -
                                        the address of the ASTE for the
                                        specified address space.
          00FFFFC0       ALEASTOM       X'7FFFFFC0' Significant bits of
                                        ASTE origin. ANDed with ALEASTE
                                        to isolate address.
0008    8 Bitstring    1 * (3)          Skip first three bytes of ASTEO
000B   11 Bitstring    1 ALEFLAGS       Flag byte origin.
          ..1. ....      ALERPRG1       X'20' Reserved for programming
                                        (in use)
     ALERPGR1 has two programming use definitions, one for use in the CP-use
     access list (ALENTDSP) and one for use in guest access lists
     (ALEPFAUL). Since an individual Access List Entry cannot be in both
     types of list at once, these two redefinitions of ALERPRG1 do not
          ..1. ....      ALENTDSP       X'20' When set in the CP-use
                                        access list, indicates the ALE
                                        designates an address space not
                                        owned by the dispatched user.
          ..1. ....      ALEPFAUL       X'20' When set in a guest access
                                        list, indicates page faults are
                                        eligible for asynchronous
                                        processing. (Pseudo page-fault
          ...1 ....      ALERPRG2       X'10' Reserved for programming
                                        (in use)
          ...1 ....      ALERACC        X'10' When set in a host access
                                        list, indicates the ALE
                                        designates that the address space
                                        be accessed with r-access.
                                        Otherwise, i-access should be
000C   12 Bitstring    4 ALEASTSN       ASTE Sequence Number - compared
                                        against an ASTE sequence number
                                        (ASTSN) in the designated ASTE
                                        during access-register
          00000010       ALELEN         *-ALEBK Entry size in bytes
          00000002       ALESIZE        (ALELEN+7)/8 Size in doublewords
                                        of the ALE
     *cmnt** ORG ALEBK+ALELEN Redefinition for second ALE in an access list:
0010   16 Bitstring    8 *              Reserved Area reserved for
0018   24 Address      4 ALEALCBK       In access lists built by CP, the
                                        second access-list entry in each
                                        access list (the one with ALEN=1)
                                        contains a pointer to the ALCBK,
                                        CP's access-list control block.
001C   28 Signed       4 *              Reserved for programming
          00000004       ALENSHFT       4 Shift needed to transform ALEN
                                        into byte offset into access


ALEBK Storage Layout

*** ALEBK - Access List Entry
*     +------+------+-------------+---------------------------+
*   0 |ALE0  |ALESN |   ALEAX     |///////////////////////////|
*     +------+------+------+------+---------------------------+
*   8 |////////////////////|:FLAGS|         ALEASTSN          |
*     +--------------------+------+---------------------------+
*  10 |///////////////////////////////////////////////////////|
*     +---------------------------+---------------------------+
*  18 |         ALEALCBK          |///////////////////////////|
*     +---------------------------+---------------------------+
*  20
*** ALEBK - Access List Entry


ALEBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
ALE            0000
ALEALCBK       0018
ALEASTE        0008
ALEASTOM       0008 00FFFFC0
ALEASTSN       000C
ALEAX          0002
ALEFLAGS       000B
ALEFONLY       0000 02
ALEINV         0000 80
ALELEN         000C 00000010
ALENSHFT       001C 00000004
ALENTDSP       000B 20
ALEPFAUL       000B 20
ALEPRIV        0000 01
ALERACC        000B 10
ALERPRG1       000B 20
ALERPRG2       000B 10
ALESIZE        000C 00000002
ALESN          0001
ALEW0          0000
ALEW0INV       0000 00
ALEW0SIG       0000 000ALEW0
ALEW0SNM       0000 000ALEW0
ALE0           0000

This information is based on z/VM V4R3.0. Last updated on 30 Apr 2002 at 15:34:38 EDT.
Copyright IBM Corporation, 1990, 2002