PGS64 DSECT
Top of page

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      PGS64          PAGE STATUS TABLE ENTRY
0000    0 Dbl-Word     8 PGSGENTR       Virtual Page Status Entry
0000    0 Signed       4 PGS64W0        PGSTE
0004    4 Signed       4 PGS64W1        Reserved for IBM use
          00000008       PGSGLENT       *-PGSGENTR Length of one Status
                                        Table Entry
0008    8 Signed       4 PGSGNEXT (0)   Next Page Status Table Entry
      PGS64W0 start - Word 0 of PGSTE
      PGSGVKEY - Byte 0 (Architected)
0000    0 Bitstring    1 PGSGVKEY       Guest Storage key bits 0-4
          1111 ....      PGSVKACC       X'F0' PGSVKACC Access-control key
                                        value
          .... 1...      PGSVKFET       X'08' PGSVKFET Fetch-protection
                                        control
          1111 1...      PGSVKACF       PGSVKACC+PGSVKFET PGSVKACF
                                        Acc-ctrl & fetch-prot bits
      PGSGRCP - Byte 1  (Architected)
0001    1 Bitstring    1 PGSGRCP        Architected area for RCP byte if
                                        storage key assist is being
                                        utilized, or the page belongs to
                                        the system.
          1... ....      PGSPCL         X'80' PGSPCL Page Control Lock
          .1.. ....      PGSRCPHR       X'40' PGSRCPHR Host backup
                                        reference bit used for system
                                        pages
          ..1. ....      PGSRCPHC       X'20' PGSRCPHC Host backup change
                                        bit used for system pages. Can be
                                        changed with PCLONLY page
                                        serialization by tasks allowed to
                                        use PCLONLY. Set by page fault
                                        fastpath. Note that when setting
                                        this bit or when resetting it and
                                        turning on the PGSZBIT bit, the
                                        relocation change bit, PGSLGRCC
                                        needs to be turned on.
          .11. ....      PGSHOST        PGSRCPHR+PGSRCPHC PGSHOST Mask
                                        for host bits
          ...1 ....      PGSLGRCC       X'10' PGSLGRCC VMRELOCATE Content
                                        Change bit. Initialized to one.
                                        Changed only when holding PCLONLY
                                        or SHORT (including ERRSHORT).
                                        Known in architecture as PGSHCB.
          .... .1..      PGSGREF        X'04' PGSGREF Guest backup
                                        reference bit
          .... ..1.      PGSGCH         X'02' PGSGCH Guest backup change
                                        bit
          .... .11.      PGSGUEST       PGSGREF+PGSGCH PGSGUEST Mask for
                                        guest bits
          1... ....      RCPLOCK        X'80' RCPLOCK RCP LOCK HELD
          .1.. ....      RCPHREF        X'40' RCPHREF HOST BACKUP
                                        REFERENCE BIT
          ..1. ....      RCPHCH         X'20' RCPHCH HOST BACKUP CHANGE
                                        BIT
          .11. ....      RCPHOST        RCPHREF+RCPHCH RCPHOST MASK FOR
                                        HOST BITS
          .... .1..      RCPGREF        X'04' RCPGREF GUEST BACKUP
                                        REFERENCE BIT
          .... ..1.      RCPGCH         X'02' RCPGCH GUEST BACKUP CHANGE
                                        BIT
          .... .11.      RCPGUEST       RCPGREF+RCPGCH RCPGUEST MASK FOR
                                        GUEST BITS
      Note that the Page Control Lock and the RCP Interlock
      bit are one in the same if the Storage Key Assist is
      being utilized.
      PGSGFLAG - Byte 2
0002    2 Bitstring    1 PGSGFLAG       Virtual Page Flags
          1... ....      PGSINVAL       X'80' PGSINVAL No auxiliary
                                        storage assigned Notes :
                                        PGSINVAL, in combination with
                                        other PTE, PGSTE, and storage key
                                        status bits, is used by steal
                                        processing to identify first time
                                        reference pages of zeros which
                                        have never been re-referenced or
                                        changed and can simply be
                                        discarded. The "first time
                                        reference page of zeros" state is
                                        identified by the following bit
                                        combination: noformat PTE:
                                        PAGINVAL=0 (page is valid and
                                        resident) PGSTE: PGSINVAL=1 (no
                                        DASD slot assigned) PGSRCPHR=0
                                        (unreferenced) PGSRCPHC=0
                                        (unchanged) Real frame storage
                                        key: Reference=0 (unreferenced)
                                        Change =0 (unchanged) enoformat
                                        Any resident page in this state
                                        is assumed to be unchanged zeros,
                                        and therefore simply discardable
                                        by steal. No page with non-zero
                                        contents should ever be allowed
                                        to be in this state, or a lost
                                        page will eventually result. The
                                        host change bit, PGSRCPHC, should
                                        be used to indicate that a page
                                        which is unchanged, not already
                                        on DASD, and non-zero, must be
                                        eventually written to DASD. *
                                        Note that both reference bits
                                        (PGSRCPHR and the real storage
                                        frame reference bit) can
                                        "evaporate" to zero over time due
                                        to the action of the reorder
                                        function. Therefore, the fact
                                        that a frame has been referenced,
                                        or setting PGSRCPHR on, can not
                                        prevent a page from eventually
                                        entering this "first time
                                        reference page of zeros" state.
          .1.. ....      PGSSHARE       X'40' PGSSHARE Page is a shared
                                        page
          ..1. ....      PGS1READ       X'20' PGS1READ ASA may be read
                                        only once. Used for shared pages.
                                        After the first read, this SDF
                                        (System Data File) ASA is to be
                                        ignored and the page left as
                                        changed. When the page is first
                                        written, it will go to a paging
                                        space ASA and this flag wil be
                                        turned off. PGS1READ on implies
                                        that page is read-only for the
                                        user.
          ...1 ....      PGSALLOC       X'10' PGSALLOC Page in the system
                                        address space (or a system-owned
                                        utility address space) that is
                                        allocated, OR A shared CP page in
                                        the monitor DCSS that CP has
                                        translated and that has not yet
                                        been released by the user
                                        connected to the DCSS. When this
                                        bit is on: 1) For a system
                                        utility space, the page is never
                                        part of a DASD block; 2) The
                                        associated PGMBK is never paged
                                        out.
          .... 1...      PGSFIXED       X'08' PGSFIXED Storage slot
                                        permanently assigned
                                        >>PGSPGMIO was PGSIO1ST,
                                        PGSIO2ND
          .... .1..      PGSPGMIO       X'04' PGSPGMIO Indicates that
                                        pageable PGMBK I/O has not
                                        completed (PTRM page). Set when
                                        the first I/O completion
                                        interrupt is processed, reset
                                        when the second I/O completion
                                        interrupt is processed. Note the
                                        I/O can complete in either order.
                                        >>PGSPGMIM was PGSIOMSK
          00000400       PGSPGMIM       (PGSPGMIO)*256 >>PGSPRBN
                                        moved from PGSGSTAT
          .... ..1.      PGSPRBN        X'02' ASA is, in fact, a PRBN
                                        (pool- relative block number)
          .... ...1      PGSREADO       X'01' Storage slot (DASD) is
                                        read-only
      PGSGSTAT - Byte 3
0003    3 Bitstring    1 PGSGSTAT       Virtual Page Status bits
          1... ....      PGSALTPT       X'80' PGSALTPT For a target PTE,
                                        indicates the definition of the
                                        page is in alternate page table
                                        pointed to by PGMGALTP. For a
                                        source PTE, indicates data was
                                        saved for the page. Source PTEs
                                        can be distinguished from target
                                        PTEs by PGMGALTP being 0.
                                        PGSALTPT must be turned off when
                                        assigning differentiated page
                                        contents to the target PTE.
          .1.. ....      PGSPCL2        X'40' PGSPCL2 Page serialization
                                        bit. See serialization section of
                                        prolog for more information.
          ..1. ....      PGSLTSER       X'20' PGSLTSER Page is "Long Term
                                        Serialized". May only be on if
                                        PGSPCL2 is also on (though PGSPCL
                                        may be on as well)
          .... ....      PGSXSTOR       X'00' PGSXSTOR Page is in XSTORE
          .... .1..      PGSBLOCK       X'04' PGSBLOCK This page is one
                                        page in a block of pages
          .... ..1.      PGSRABI        X'02' PGSRABI This page was read
                                        in as part of a block of pages.
                                        This bit can NOT be checked for
                                        PTRM pages, as it is redefined as
                                        PGSXSTMB in that case. RABI pages
                                        are made IBR when added to the
                                        frame list.
          .... ...1      PGSERROR       X'01' PGSERROR Page is in error.
                                        A storage error was detected in
                                        this page and the page could not
                                        be recovered. See serialization
                                        section of the prolog for role
                                        this bit plays in page
                                        serialization. When this bit is
                                        set, VMDRSSFG.VMDRSSUE must be
                                        set in the VMDBK that owns the
                                        space.
      PGS64W1 start - Word 1 of PGSTE
      PGSBYTE 4 Additional status bits  (Architected)
0004    4 Bitstring    1 PGSBYTE4       Byte 4 of page status entry
          1... ....      PGSZBIT        X'80' PGSZBIT
                                        Page-content-logically zero bit
                                        Only meaningful when the PTE is
                                        invalid.
          .1.. ....      PGSNT          X'40' PGSNT Guest no translation.
                                        When ON the guest page does not
                                        contain any DAT structures.
          ..1. ....      PGSCLASS       X'20' PGSCLASS The page class
                                        specifies which
                                        Delta-pinned-page-count array is
                                        to be used in maintaining pinned
                                        page counts. Page class 0 (bit is
                                        0) specifies the DPPCA for base
                                        address space pages owned by
                                        user. Page class 1 (bit is 1)
                                        specifies NSS/DCSS imbedded
                                        shared pages. The page class 0
                                        DPPCA resides in the ASCBK and is
                                        pointed to by SIEDPPCAO in the
                                        format-2 state descriptor
                                        (SI2BK). The page class 1 DPPCA
                                        resides resides in RSMBK and is
                                        pointed to by PFXDPPCAO in the
                                        prefix area.
          ...1 ....      PGSOVFLW       X'10' PGSOVFLW The pin count
                                        (PGSPINCT) has overflowed and the
                                        current value does not represent
                                        the total pin count. The
                                        remainder of the total pin count
                                        is contained in both PGSOVFL1 (a
                                        one bit pin count overflow used
                                        to control hardware interception)
                                        and PGAOVFLW in the PGAUX). PTE
                                        must be valid. Can be modified
                                        with PCLONLY page serialization
                                        by tasks allowed to use PCLONLY.
                                        Set by pin/unpin fastpaths,
                                        translation paths, and no-owned
                                        functions. Before setting
                                        PGSOVFLW, PGAUX should be cleared
                                        to ensure no residual data is
                                        present.
          .... 1...      PGSPROCL       X'08' PGSPROCL Indicates page is
                                        on the processed list. Turned on
                                        by machine or fast path
                                        processing when corresponding
                                        FRMTE is put on processed list.
                                        Turned off by HCPPLP processed
                                        list processing. Can be modified
                                        with PCLONLY page serialization
                                        by tasks allowed to use PCLONLY.
                                        Set by HPMA or fastpath validate
                                        page. See PFXPROCL definition
                                        comments in HCPPFXPG for
                                        additional rules regarding
                                        processed list usage and the
                                        setting of PGSPROCL.
          .... .1..      PGSCONRP       X'04' PGSCONRP Indicates a
                                        content-replacement operation
                                        occurred on an HPMA Resolve host
                                        page function. Can be modified
                                        with PCLONLY page serialization
                                        by tasks allowed to use PCLONLY.
                                        Set by HPMA or fastpath validate
                                        page.
          .... ..1.      PGSUS0         X'02' PGSUS0
          .... ...1      PGSUS1         X'01' PGSUS1
          .... ..11      PGSUS          PGSUS0+PGSUS1 PGSUS
          .... ....      PGSUSS         0 PGSUSS
          .... ...1      PGSUSU         1 PGSUSU
          .... ..1.      PGSUSP         2 PGSUSP
          .... ..11      PGSUSV         3 PGSUSV
      PGSBYTE 5 Additional status bits   (Architected)
0005    5 Bitstring    1 PGSBYTE5       Byte 5 of page status entry
          1... ....      PGSIBR         X'80' PGSIBR Page is in IBR
                                        section of UFO The PTE associated
                                        with the frame is likely to be
                                        invalid; however, it may be a
                                        valid PTE whose frame has not yet
                                        been moved to the active section
                                        of the frame list.
          .1.. ....      PGSAGING       X'40' PGSAGING Frame/FRMTE is on
                                        the system's global IBR aging
                                        list
          ...1 ....      PGSPN0         X'10' PGSPN0
          .... 1...      PGSPN1         X'08' PGSPN1
          ...1 1...      PGSPN          PGSPN0+PGSPN1 PGSPN Two-bit code
      PGSBYTE 6 Additional status bits
0006    6 Bitstring    1 PGSBYTE6       Byte 6 of page status entry
                                        >>PGSCMDLK was FRMCPLOK
          1... ....      PGSCPLOK       X'80' PGSCPLOK A pageable page is
                                        locked in the frame (pinned) by
                                        the CP LOCK command, one
                                        increment of the total pin count
                                        represents the CP LOCK command
                                        lock. >>PGSD98LK was
                                        PGSVMSLK
          .1.. ....      PGSD98LK       X'40' PGSD98LK A pageable page is
                                        locked in the frame (pinned) at
                                        Virtual Machine request via
                                        Diagnose x'98', one increment of
                                        the total pin count represents
                                        the Diagnose x'98' Virtual
                                        Machine lock.
          ..1. ....      PGSEWRTC       X'20' PGSEWRTC Page contents were
                                        written to DASD during the "early
                                        write" phase of being on the
                                        Aging List; reason for write was
                                        the page was changed
          ...1 ....      PGSEWRTM       X'10' PGSEWRTM Page contents were
                                        written to DASD during the "early
                                        write" phase of being on the
                                        Aging List; reason for write was
                                        not the change bits (bad mload,
                                        drained, etc)
          .... 1...      PGSAGRCL       X'08' PGSAGRCL Page is on the
                                        Aging List ready to be reclaimed
                                        (that is, it is below the early
                                        write pointer)
          .... ..1.      PGSALIAS       X'02' PGSALIAS Guest page has an
                                        SXS alias. This bit can only be
                                        tested if PAGGINVA is not set;
                                        i.e. the PTE must be valid.
          .... ...1      PGSOVFL1       X'01' PGSOVFL1 A one bit pin
                                        count overflow count bit. Used to
                                        hold one pin count out of
                                        PGSPINCT to control hardware
                                        interception. PTE must be valid.
                                        Can be modified with PCLONLY page
                                        serialization by tasks allowed to
                                        use PCLONLY. Turned on/off by
                                        pin/unpin fastpaths, translation
                                        paths, and no-owned functions.
                                        Also turned on by HCPTRANS
                                        HOSTTYPE=LOGICAL, TRANSLATE=NO,
                                        LOCK=YES of a no-owned page that
                                        wasn't locked or pinned but was
                                        last translated. Gets turned off
                                        in edge-triggered cases.
0007    7 Bitstring    1 PGSPINCT       Pin Count. Represents the number
                                        of pins (page locks) visible to
                                        hardware. If PGSOVFLW is set,
                                        does not represent the true total
                                        pin count. Additional pin count
                                        values are held in PGSOVFL1 (a
                                        one bit pin overflow count used
                                        to control hardware interception)
                                        and PGAOVFLW (a halfword pin
                                        overflow count where each "1"
                                        increment represents 128 pin
                                        count increments). PTE must be
                                        valid. Can be modified with
                                        PCLONLY page serialization by
                                        tasks allowed to use PCLONLY.
                                        Turned on/off by pin/unpin
                                        fastpaths, translation paths, and
                                        no-owned functions.
      PGS64W1 end
      Redefinition of PGSGSTAT for Pageable PGMBK (PTRM) pages
0003    3 Bitstring    1 PGSGPSTA       Pageable PGMBK Virtual Page
                                        Status bits.
          .... ..1.      PGSXSTMB       X'02' This page (a pageable
                                        PGMBK) itself supports pages in
                                        XSTORE. This bit is only used for
                                        PTRM pages that currently reside
                                        in XSTORE (PGSXSTOR must also be
                                        on if PGSXSTMB is on). Note that
                                        this bit is a redefinition of the
                                        PGSRABI bit, which is acceptable
                                        since pageable PGMBKs (PTRM
                                        pages) are never blocked.
0004    4 Signed       4 PGSPPDBK       Address of PPDBK for paged PGMBK.
                                        Note that the PPDBK address is a
                                        31-bit address, occupying bits
                                        1-31 of this word. Note that
                                        PGSZBIT is meaningless and
                                        irrelevant for PTRM pages. Valid
                                        only in invalid PTRM PGSTE, when
                                        PGMBK is on DASD, or as a
                                        transient condition when the
                                        PGMBK may be headed to DASD.

          
*** PGS64 - PAGE STATUS TABLE ENTRY
*
*     +-------------------------------------------------------+
*   0 |                       PGSGENTR                        |
*     +-------------------------------------------------------+
*   8
*
*** PGS64 - PAGE STATUS TABLE ENTRY
          
*** Overlay for PGSGENTR in PGS64
*
*     +---------------------------+---------------------------+
*   0 |         PGS64W0           |         PGS64W1           |
*     +---------------------------+---------------------------+
*
*** Overlay for PGSGENTR in PGS64
          
*** Overlay for PGS64W0 in PGS64
*
*     +------+------+------+------+------+------+------+------+
*   0 |:GVKEY|:GRCP |:GFLAG|:GSTAT|:BYTE4|:BYTE5|:BYTE6|:PINCT|
*     +------+------+------+------+------+------+------+------+
*   8
*
*** Overlay for PGS64W0 in PGS64
          
*** Overlay for PGSGSTAT in PGS64
*
*                          +------+
*   0 ...                3 |:GPSTA| 4
*                          +------+
*
*** Overlay for PGSGSTAT in PGS64
          
*** Overlay for PGS64W1 in PGS64
*
*                                 +---------------------------+
*   0 ...                       4 |         PGSPPDBK          |
*                                 +---------------------------+
*   8
*
*** Overlay for PGS64W1 in PGS64

 
Symbol         Dspl Value
-------------- ---- -----
PGSAGING       0005 40
PGSAGRCL       0006 08
PGSALIAS       0006 02
PGSALLOC       0002 10
PGSALTPT       0003 80
PGSBLOCK       0003 04
PGSBYTE4       0004
PGSBYTE5       0005
PGSBYTE6       0006
PGSCLASS       0004 20
PGSCONRP       0004 04
PGSCPLOK       0006 80
PGSD98LK       0006 40
PGSERROR       0003 01
PGSEWRTC       0006 20
PGSEWRTM       0006 10
PGSFIXED       0002 08
PGSGCH         0001 02
PGSGENTR       0000
PGSGFLAG       0002
PGSGLENT       0004 00000008
PGSGNEXT       0008
PGSGPSTA       0003
PGSGRCP        0001
PGSGREF        0001 04
PGSGSTAT       0003
PGSGUEST       0001 06
PGSGVKEY       0000
PGSHOST        0001 60
PGSIBR         0005 80
PGSINVAL       0002 80
PGSLGRCC       0001 10
PGSLTSER       0003 20
PGSNT          0004 40
PGSOVFLW       0004 10
PGSOVFL1       0006 01
PGSPCL         0001 80
PGSPCL2        0003 40
PGSPGMIM       0002 00000400
PGSPGMIO       0002 04
PGSPINCT       0007
PGSPN          0005 18
PGSPN0         0005 10
PGSPN1         0005 08
PGSPPDBK       0004
PGSPRBN        0002 02
PGSPROCL       0004 08
PGSRABI        0003 02
PGSRCPHC       0001 20
PGSRCPHR       0001 40
PGSREADO       0002 01
PGSSHARE       0002 40
PGSUS          0004 03
PGSUSP         0004 02
PGSUSS         0004 00
PGSUSU         0004 01
PGSUSV         0004 03
PGSUS0         0004 02
PGSUS1         0004 01
PGSVKACC       0000 F0
PGSVKACF       0000 F8
PGSVKFET       0000 08
PGSXSTMB       0003 02
PGSXSTOR       0003 00
PGSZBIT        0004 80
PGS1READ       0002 20
PGS64W0        0000
PGS64W1        0004
RCPGCH         0001 02
RCPGREF        0001 04
RCPGUEST       0001 06
RCPHCH         0001 20
RCPHOST        0001 60
RCPHREF        0001 40
RCPLOCK        0001 80