I I S!.boli£ l@!!! !eani]!!1 RDEYTYPC Real device type class RDBYTYPE Real device type RDEf!DL Real device .odel nu.ber RDEVFTR Real device feature code for a device other than a
virtual console
RDEVLL!N Current device line length for a local virtual console NICDTYPE Real device type for a re.ote 3210 virtual console NICMDL Real device .odel nu.ber for a re.ote 3210 virtual
console NICLLEK Current device line length for a re.ote virtual console
The following chart lists the condition DIAGNOSE code 1'24', the .eaning of each
registers where data is returned.
If the condition
code equals
o
1
This register
contains infor.ation
Ry I x I codes CP can return
condition code, and
Co •• ents
Bor.al co.pletion Undefined for
the
2 x x The virtual device eJists but is not asso­
ciated with a real
device
3 Invalid device address
or the virtual device
does not exist 'The Rx register contains infor.ation only when DIAGNOSE code 1'24' specifies a virtual console whose address in unknown.
2If Ry is register 15, CP returns only virtual device infor.ation: no
infor.ation is returned in register Ry.1. DI!§!QSE == ChlAA!!! Progra. !odification DIAGNOSE code 1'28' allows a virtual .achine to correctly execute so.e
channel progra.s .odified after the Start I/O (510) instruction is
issued and before the input/output operation is co.pleted. The channel
co •• and word (CCI) .odifications allowed are: 1 Transfer in Channel (TIC) CCI .odified to a Bo Operation (BOP) eCI 1 TIC CCI .odified to point to a new list of CCls 1 BOP .odified to a TIe eel 1-60 IB! V8/310 Syste. Logic and Proble. Deter.ination--Volu.e 1
When a virtual machine .odifies a TIC CCW, it is .odifying a virtual
channel progra.. CP has already translated that channel progra. and is
waiting to execute the real CCWs. The DIAGBOSE instruction, with code X'28', must be issued to inform CP of the change in the virtual channel program, so that CP can .ake the corresponding change to the real CCW before it is executed. In addition, when a BOP CCW is .odified to point
to a new list of CCWs, CP translates the new CCWs. To be sure that the DIAGBOSE instruction is recognized in ti.e to update the real CCW chain, the virtual .achine issuing the DIAGBOSE instruction should have a high favored execution value and a low
dispatching priority value. The CP SET co.mand should be issued: SET FAVORED xx SET PRIORITY nn
where xx has a high nu.eric value and nn has a low nu.eric value. The virtual .achine issuing the DIAGBOSE code X'28' .ust be in the
supervisor mode at the time it issues the DIAGBOS! instruction. When DIAGBOSE code 1'28' is issued, the Rx register contains the
address of the TIC or BOP CCW that was .odified by the virtual .achine.
The Ry register contains the device address in bits 16 through 31 •. Rx and Ry cannot be the sa.e register.. The addresses specified in the Bx register, the new address in the .odified TIC CCW, and the new CCW list
to which the .odified TIC CCW points .ust all be addresses that appear
real to the virtual machine: CP knows these addresses are virtual, but
the virtual machine thinks they are real. The condition codes (cc) and completion codes are as follows:
ce:O The real channel progra. was successfully .odified; register
15 contains a zero.
cc=l There was probably an error in issuing the DIAGBOSE instruction. Register 15 (R15) contains one of the following
completion codes:
R15=1 The sa.e register was specified for Rx and Ry. R15=2 The device specified by the Ry register vas not found.
R15=3 The address specified by the Rx register vas not within the user's storage space.
R15=4 The address specified by the Rx register was not
doubleword aligned.
R15=5 A CCW string corresponding to the device (Ry) and
address (Rx) specified vas not found.
R15=6 The CCW at the address specified by the Rx register is
not a TIC nor a BOP, or the CCW in the channel progra.
is not a TIC nor a BOP. R15=7 The new address in the .odified TIC CCW is not within
the user's storage space.
R15=8 The new address in the .odified TIC CCW is not
doubleword aligned.
cc=2 The real channel prograa cannot be .odified because a channel
end or device end already occurred. Register 15 contains a 9.
The virtual machine should restart the .odified channel
prograa.
CP Introduction 1-61
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