The channel mode
channel zero can
CHANNEL command. CPUID bbbbbb
Directory Program setting for all channels
be changed by the use of
except virtual
the CP DEFINE
provides a unique processor identification (CPUID) to be
stored in response to the STIDP instruction. It is necessary
to associate a unique CPUID with each virtual machine that is
attached to an MSC port since solicited/unsolicited messages
are directed to the host system in the virtual environment by
means of the CPUID. There is no checking by VM/370 to ensure
that all virtual machines using the SET CPUID command have
specified unique processor serials. The hexadecimal field Ibbbbbb
i is the processor identification number. The
processor identification number (serial) is only a portion of
the complete CPUID. The CPUID identification stored in
response to a STIDP instruction is a string of 16 hexadecimal
digits shown as follows:
aabbbbbbccccdddd
aa is the version code; these X'FF' to identify that the
under VM/370. two digits are forced to
virtual machine is running
bbbbbb is up to 6 hexadecimal digits that indicate the
processor identification number; this field is set by
the directory OPTION statement values or modified by
the SET CPUID command.
cccc is the model number; this field contains a high order
o digit followed by the three digits of the model
number (0-9). This field defaults to the model number
of the real machine.
dddd is the machine check extended logout; this field is
forced to X'OOOO' since CP does not reflect machine
checks to the virtual machine.
If the CPUID was not specified by means of the SET CPUID command or the OPTION control statement, the CPUID stored as a
result of the STIDP instruction is the real CPUID with the
first two digits set to X'FF' and the last four digits set to X'OOOO' (present CPUID logic). A processor serial of more
than six digits on the SET CPUID command results in an error
message.
A processor identification number (serial) of less than six
hexadecimal digits results in zeros being padded to the left
of the number. A three-byte field in the VMBLOK (VMCPUID) contains the value set as a result of invoking this DIRECTORY option. AFFINITY nn
is 2 decimal digits between 00 and 63 that specify that
virtual machine execution is to be performed on a designated
processor (nn). This attribute is only applicable in the VM/370 attached processor environments. Any hexadecimal value
from 00 to 3F is a valid main or attached processor address;
however, the value selected must match the preset values
established for your installation's main and attached
processor when the system was installed. If the AFFINITY option is not selected, then the virtual machine is serviced Part 2. Defining Your VM/370 System 205

Directory Program by the first available processor from the Vft/370 dispatch
queue. An affinity setting in the Vft/370 directory can be
overridden by the CP SET AFFINITY command. If the system is
running in attached processor mode and an error forces
recovery to uniprocessor mode, the affinity setting of virtual
machines assigned to the attached processor is nullified and
virtual machine processing may be continued on the main
processor.
The IPL control statement contains a one-to eight-character name of the
system (or one-to three-digit I/O device address) to be loaded for the user when he logs on. This statement is optional; if specified, it must
follow the USER statement, and must precede the first device statement (CONSOLE, MDISK, or SPOOL). The IPL statement can be overridden by the
user at logon time by specifying "LOGON userid NOIPL". If the user is the primary system operator, an automatic IPL is n2£ performed when he logs on.
The format of the IPL statement is:
r , Ipl iplsys
L
iplsys is a one-to eight-character system name or the virtual
address of the device containing the system to be loaded.
The CONSOLE control statement specifies the virtual console. The format
of the CONSOLE control statement is: ro- , Console cuu devtype (class]
L
cuu is the virtual device address of one to three hexadecimal
digits.
devtype is the device type: 1052 3210 3215
Note: The system accepts any of the devtypes indicated regardless of the real console or terminal being used. Device
types 3275, 3276, 3277, 3278, 3036, 3066, 3138, 3148, 3158,
2741, and 3767 cannot be specified. Only one console can be
specified. If a different console is sometimes required, use
the CP DEFINE command to change the console address or add an
alternate console. 206 IBM VM/370 Planning and System Generation Guide