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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.
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