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

#### PAGTE

Prolog

Control Block Contents
PAGTE DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### PAGTE Prolog

     Name       : HCPPAGTE
     Description: Page Table Entry
     DSECT      : PAGTE
     Function   : A Page Table Entry is a hardware architected
                  area that describes one 4K page of virtual
                  storage.  In ESA/390 mode, Page Table Entries
                  are one word (4 bytes) in length.  In ESAME
                  mode, page table entries are one doubleword
                  (8 bytes) in length.
     Located by : ESA/390 mode:
                  PGMPAGTB in a PGMBK + (page offset * 4)
                  FRMPTE   field of HCPFRMTE (31 bit address)
                  ESAME mode:
                  PGMPAGTB in a PGMBK + (page offset * 8)
                  FRMPTE   field of HCPFRMTE (31 bit address)
                  A page table resides in a Page Management Block
                  (PGMBK) associated with a megabyte of virtual
                  storage, and is located by PGMPAGTB and pointed
                  to by the Page Table Origin (PTO) portion of a
                  valid Segment Table Entry (STE).  There are (up
                  to) 256 contiguous page table entries in a page
                  table.  (ESA/390 page tables may have less than
                  than 256 entries, depending on the Page Table
                  Length field SEGPTL in the STE associated with
                  the page table.  ESAME page tables must always be
                  a full 256 entries in length.)
                  A page table entry may be pointed to by the FRMPTE
                  field of a frame table entry if a frame is
                  associated with the page.
                  Any specific page table entry can be obtained by
                  extracting the page number (bits 12-19 for ESA390
                  and bits 44-51 for ESAME) from the vitrual address
                  and, by multiplying the page number by the correct
                  PTE length, calculating the offset into the
                  page table.
     CREATED BY : HCPBPBCU
                  HCPBPBIE
                  HCPBPBIM
                  HCPBPBSL
                  A page table is imbedded in a page management
                  block and consequently space for the PTE is
                  created when the PGMBK is created.
                  At initialization time, information for CP pagable
                  initialization modules is put in PTEs by HCPISTOR.
                  After initialization, the infromation within each
                  PTE is filled in my HCPTRANS.
     DELETED BY : HCPRCIRL
                  HCPRPBPA
                  HCPRPBPS
                  HCPRPBRM
                  HCPRPBSL
                  A page table is deleted when a page management
                  block is released.

#### PAGTE Control Block Content

#### PAGTE DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      PAGTE          Page Table Entry
         ESA/390 mode Page-Table Entry format
    0000    0 Signed       4 PAGENTRY       HARDWARE PAGE TABLE ENTRY
              PAGENTRY       PAGPFRAM       X'7FFFF000' Isolate
                                            page-frame-real address
              PAGENTRY       PAGPTOM        X'7FFFFC00' Isolate Page Table
                                            Origin (PTO) given the address of
                                            a PTE
              PAGENTRY       PAGINVM        X'00000400' Isolate page-invalid
                                            bit
              PAGENTRY       PAGPROTM       X'00000200' Isolate
                                            page-protection bit
              PAGENTRY       PAGRSVM        X'80000900' Reserved bits, must
                                            be 0 in any valid PTE
              00000004       PAGLENTH       *-PAGENTRY LENGTH OF ONE PAGE
                                            TABLE ENTRY
    0004    4 Signed       4 PAGNEXT (0)    NEXT PAGE TABLE ENTRY
    0000    0 Bitstring    1 *              BITS 1-19 ARE ARCHITECTED AS THE
    0001    1 Bitstring    1 *              4K ALIGNED PAGE FRAME ADDRESS.
    0002    2 Bitstring    1 PAGSTAT        BITS 0, 20, AND 23 MUST BE ZERO,
                                            BITS 21 AND 22 ARE DEFINED BELOW.
              .... .1..      PAGINVAL       X'04' PAGE TABLE ENTRY IS INVALID
              .... ..1.      PAGPROT        X'02' PAGE PROTECTED (READ ONLY)
         The following definitions are for Minidisk cache virtual address space
         data pages. MDC uses these bits rather than the ones in the PGSTE
         because MDC uses compact page tables (4 page tables per frame).
              .... ...1      PAGXSVAL       X'01' Indicates that an invalid
                                            MDC PTE is valid in XSTORE.
    0003    3 Bitstring    1 PAGSTAT2       Second status byte
              .... .1..      PAGXSREF       X'04' Indicates that the XSTORE
                                            block has been referenced.
         The following maps the page-table entry in the System/370 architecture.
         Note that System/370 page-table entries are only two bytes long; these
         mask definitions assume that the two byte System/370 PTE value is
         loaded into the rightmost two bytes of a GPR.
              0000FFF0       PAG3PF4M       X'0000FFF0' Isolate
                                            page-frame-real address for S/370
                                            PTE, 4K pages
              .... 1...      PAG3IN4M       X'00000008' Isolate page-invalid
                                            bit for S/370 PTE, 4K pages
              .... .11.      PAG3EA4M       X'00000006' Isolate
                                            extended-storage-address bits for
                                            S/370 PTE, 4K pages
              00FF0008       PAG3RS4M       X'FFFF0008' Reserved bits, must
                                            be 0 in any valid S/370 PTE, 2K
                                            pages
              0000FFF8       PAG3PF2M       X'0000FFF8' Isolate
                                            page-frame-real address for S/370
                                            PTE, 2K pages
              .... .1..      PAG3IN2M       X'00000004' Isolate page-invalid
                                            bit for S/370 PTE, 2K pages
              00FF0006       PAG3RS2M       X'FFFF0006' Reserved bits, must
                                            be 0 in any valid S/370 PTE, 2K
                                            pages
              00FF0001       PAG3B15M       X'FFFF0001' S/370 PTE bit 15 is
                                            unassigned and not checked for
         *

#### PAGTE Storage Layout

    *** PAGTE - Page Table Entry
    *
    *     +---------------------------+
    *   0 |         PAGENTRY          |
    *     +---------------------------+
    *
    *** PAGTE - Page Table Entry

    *** Overlay for PAGENTRY in PAGTE
    *
    *     +------+------+------+------+
    *   0 |//////|//////|:STAT |:STAT2| 4
    *     +------+------+------+------+
    *
    *** Overlay for PAGENTRY in PAGTE

#### PAGTE Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    PAGENTRY       0000
    PAGINVAL       0002 04
    PAGINVM        0000 PAGENTRY
    PAGLENTH       0000 00000004
    PAGNEXT        0004
    PAGPFRAM       0000 PAGENTRY
    PAGPROT        0002 02
    PAGPROTM       0000 PAGENTRY
    PAGPTOM        0000 PAGENTRY
    PAGRSVM        0000 PAGENTRY
    PAGSTAT        0002
    PAGSTAT2       0003
    PAGXSREF       0003 04
    PAGXSVAL       0002 01
    PAG3B15M       0003 00FF0001
    PAG3EA4M       0003 06
    PAG3IN2M       0003 04
    PAG3IN4M       0003 08
    PAG3PF2M       0003 0000FFF8
    PAG3PF4M       0003 0000FFF0
    PAG3RS2M       0003 00FF0006
    PAG3RS4M       0003 00FF0008

This information is based on z/VM V4R3.0. Last updated on 30 Apr 2002 at 18:26:43 EDT.
Copyright IBM Corporation, 1990, 2002