VPABK | Back to Index page

| Prolog Control Block Contents VPABK DSECT VPALE 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.

VPABK Prolog | Top of page

     NAME       : HCPVPABK
     DESCRIPTION: Virtual Page Array (Guest Relocation)
     DSECT      : VPABK
     FUNCTION   : This control block is used during Live Guest
                  Relocation to accumulate a set of guest pages to be
                  sent from the source system to the destination system.
                  It is tightly coupled to the HCPGSBBK.
      ocated by
                  - On the source system: this block is contained
                  within the HCPGSBBK (see GSBVPA).
                  - On the destination system: located by the first
                  fragment received (host logical address).
     CREATED BY : - On the source system: Created as part of the GSBBK.
                  - On the destination system: Received as the first
                  fragment from ISFC and mapped in situ.
     DELETED BY : - On the source system: Deleted as part of the GSBBK.
                  - On the destination system:
                  1) The receive loop (HCPRLBRC) when the VPABK is
                  for state changes and/or updated resident/xstore
                  pages.  (VPAFLAG.VPAPWM is on.)
                  2) The DASD handler (HCPDOPMW) when the VPABK is
                  for updated DASD pages.  (VPAFLAG.VPAPWM is off.)
     REFERENCES : HCPRLMSG COPY
     SERIALIZED : Only one task should have the address
                  of a particular VPABK.
     RELOCATION CONSIDERATIONS : None
      otes
                  - The entire VPABK is transmitted from the
                  source system to the destination system.
                  - The VPABK is broken into two main parts.
                  See each part for more information.
                  - Header information
                  - VPARRAY: Virtual Page Array.
                  - Sample HCPUSING
                  HCPUSING GSBBK,R7           Address GSBBK.
                  HCPUSING VPABK,GSBVPA,GSBBK Address VPABK.
                  USING RLMSG,VPAMSG          Address RLMSG.
      t*    HCPUSING RLMSG,VPAMSG,VPABK Address RLMSG.
                  - HCPUSING can not be used for the RLMSG at this
                  time, see 2T0K184.

VPABK Control Block Content | Top of page

     VPABK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      VPABK          Virtual Page Array (Guest Relocation)
          This area is the header information.  This is transmitted
          from the source system to the destination system.
    0000    0 Signed       4 VPAHEAD (0)    Start of VPA Header.
                 VPAMSG is mapped by RLMSG DSECT in HCPRLMSG COPY.
    0000    0 Dbl-Word     8 VPAMSG
    0008    8 Signed       2 VPACURPS       Number of the memory pass in
                                            progress
    000A   10 Signed       2 VPAPGCNT       Page Count. On the destination
                                            side, this will indicate the
                                            total number of entries in the
                                            VPARRAY, all of which are filled
                                            in. On the source side this will
                                            be used as a count of entries as
                                            they are filled in, while
                                            GSBPGCNT is the total number of
                                            entries.
    000C   12 Signed       4 VPAASCID (0)   Address space identifier.
                                            Consists of 2 halfword index
                                            fields. A value of negative one
                                            indicates base space. (See also
                                            RLOASCID).
    000C   12 Signed       2 VPAAIDOF       ASCBK ID offset. Offset into
                                            VDISK location table.
    000E   14 Signed       2 VPAAIDIN       ASCBK ID index. Index into the
                                            VDIBK to get the entry for the
                                            corresponding address space.
    0010   16 Dbl-Word     8 * (2)          Reserved
              00000020       VPAHDSZB       *-VPAHEAD Size of VPAHEAD in
                                            bytes.
              00000004       VPAHDSZD       (VPAHDSZB+7)/8 Size of VPAHEAD in
                                            double words.
          - VPAL is the list of Virtual Page Address List Entries.
          - Each virtual page address list entry is
            mapped by VPALE DSECT.
          - This section is transmitted from the source
            system to the destination system.
          - It is variable length in size.  On the destination side,
            its length is defined by VPAPGCNT.  On the source side,
            its length is defined by GSBPGCNT, while VPAPGCNT
            is a running count of entries as they are processed.
    0020   32 Dbl-Word     8 VPARRAY (0)    Beginning of the Virtual Page
                                            Array.
          Virtual Page Address List Entry (transmitted)
          Format of double word 0
                    1         2         3         4         5         6
          0123456789012345678901234567890123456789012345678901234567890123
          xdzebncstttttttt******************************--i----Tuuaaaafrc-
          PDESA---VPAXTIME                                PDESC---PDESD---
          x = Page was in xstore on the source system
          d = Page was on DASD on the source system
          z = z bit (page logically 0)  (no page contents transmitted)
          e = page in error bit         (no page contents transmitted)
          b = Host backup change bit.
          n = Host backup reference bit.
          c = Content sent.  1=Content sent.  0=No content sent.
          s = Segment z bit.  Segment is logically zero.
          tttttttt = 8 bit timestamp for XSTORE hint information.
                     bits 17-24 of the XSTORE timestamp (delta from TOD).
          i = PGSIBR
          T = PGSNT
          u = PGSUS
          a = key access bits
          f = key fetch protect bit
          r = guest-view reference bit
          c = guest-view change bit
          - = reserved for future use
          Format of double word 1
                    1         2         3         4         5         6
          0123456789012345678901234567890123456789012345678901234567890123
          vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv------------
          v = Virtual Page address bits
          - = reserved for future use

     VPALE DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      VPALE          Virtual Page Array (Guest Relocation)
    0000    0 Bitstring    8 VPADATA        Virtual Page Data (State, etc.)
    0008    8 Address      8 VPAVPADR       Virtual Page address.
              00000010       VPAAESZB       *-VPALE Size of 1 VPALE in bytes.
              00000002       VPAAESZD       (VPAAESZB+7)/8 Size of 1 VPALE in
                                            double words.
    0000    0 Bitstring    1 VPAPDESA       Page description flag byte A A
                                            page that is resident on the
                                            source system is recognized by
                                            having VPASRCX, VPASRCD, VPAVPGZ,
                                            and VPAVPGE off.
              1... ....      VPASRCX        X'80' VPASRCX Page is in XSTORE
                                            on the source system.
              .1.. ....      VPASRCD        X'40' VPASRCD Page is on DASD on
                                            the source system.
              ..1. ....      VPAVPGZ        X'20' VPAVPGZ Page logically 0
                                            (no page contents buffer
                                            transmitted)
              ...1 ....      VPAVPGE        X'10' VPAVPGE Page in error (no
                                            page contents buffer transmitted)
              .... 1...      VPAHBR         X'08' VPAHBR Host backup
                                            reference bit.
              .... .1..      VPAHBC         X'04' VPAHBC Host backup change
                                            bit.
              .... ..1.      VPACTENT       X'02' VPACTENT Content bit.
                                            Source system: Set to indicate
                                            corresponding real buffer address
                                            has a non-zero address.
                                            Destination system: Indicates if
                                            content was sent for this virtual
                                            page address.
              .... ...1      VPASEGZ        X'01' VPASEGZ The seqment
                                            beginning at the virtual page
                                            address is invalid.
    0001    1 Bitstring    1 VPAXTIME       Delta timestamp for XSTORE.
    0002    2 Bitstring    1 * (4)          Bits 16-47 Reserved for future
                                            use.
    0006    6 Bitstring    1 VPAPDESC       Page description flag byte C
              1... ....      VPAIBR         X'80' VPAIBR Page is invalid but
                                            resident (may be on aging list or
                                            UFO) Source system: Used only on
                                            source. Destination system: Not
                                            used
              .... .1..      VPANT          X'04' VPANT PGSNT bit
              .... ..1.      VPAUS0         X'02' VPAUS0
              .... ...1      VPAUS1         X'01' VPAUS1
              .... ..11      VPAUS          VPAUS0+VPAUS1 VPAUS
    0007    7 Bitstring    1 VPAPDESD       Page description flag byte D
              1111 ....      VPAACC         X'F0' VPAACC Access bits of
                                            storage key.
              .... 1...      VPAVPGF        X'08' Fetch protect bit of
                                            storage key.
              .... .1..      VPAVPGVR       X'04' Guest View reference bit
              .... ..1.      VPAVPGVC       X'02' Guest View change bit
              00FFFFFF       VPAMAXGPH      X'FFFFFFFF' Max guest page that
                                            can
              00FFF000       VPAMAXGPL      X'FFFFF000' exist for a guest to
                                            be eligible for relocation.

VPABK Storage Layout | Top of page

    *** VPABK - Virtual Page Array (Guest Relocation)
    *
    *     +-------------------------------------------------------+
    *   0 |                        VPAMSG                         |
    *     +-------------+-------------+-------------+-------------+
    *   8 |  VPACURPS   |  VPAPGCNT   |  VPAAIDOF   |  VPAAIDIN   |
    *     +-------------+-------------+-------------+-------------+
    *  10 |///////////////////////////////////////////////////////|
    *     |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *
    *** VPABK - Virtual Page Array (Guest Relocation)

    *** VPALE - Virtual Page Array (Guest Relocation)
    *
    *     +-------------------------------------------------------+
    *   0 |                       VPADATA                         |
    *     +-------------------------------------------------------+
    *   8 |                       VPAVPADR                        |
    *     +-------------------------------------------------------+
    *  10
    *
    *** VPALE - Virtual Page Array (Guest Relocation)

    *** Overlay for VPADATA in VPALE
    *
    *     +------+------+---------------------------+------+------+
    *   0 |:PDESA|:XTIME|///////////////////////////|:PDESC|:PDESD|
    *     +------+------+---------------------------+------+------+
    *   8
    *
    *** Overlay for VPADATA in VPALE

VPABK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    VPAACC         0007 F0
    VPAAESZB       0008 00000010
    VPAAESZD       0008 00000002
    VPAAIDIN       000E
    VPAAIDOF       000C
    VPAASCID       000C
    VPACTENT       0000 02
    VPACURPS       0008
    VPADATA        0000
    VPAHBC         0000 04
    VPAHBR         0000 08
    VPAHDSZB       0010 00000020
    VPAHDSZD       0010 00000004
    VPAHEAD        0000
    VPAIBR         0006 80
    VPAMAXGPH      0007 00FFFFFF
    VPAMAXGPL      0007 00FFF000
    VPAMSG         0000
    VPANT          0006 04
    VPAPDESA       0000
    VPAPDESC       0006
    VPAPDESD       0007
    VPAPGCNT       000A
    VPARRAY        0020
    VPASEGZ        0000 01
    VPASRCD        0000 40
    VPASRCX        0000 80
    VPAUS          0006 03
    VPAUS0         0006 02
    VPAUS1         0006 01
    VPAVPADR       0008
    VPAVPGE        0000 10
    VPAVPGF        0007 08
    VPAVPGVC       0007 02
    VPAVPGVR       0007 04
    VPAVPGZ        0000 20
    VPAXTIME       0001

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:31:41 EDT.
Copyright IBM Corporation, 1990, 2020