z/VM: CP Commands and Utilities Reference - z/VM - IBM

TRACE: Options
Usage Notes
1608 z/VM: CP Commands and Utilities Reference
NODAT
requests that the specified tracing be restricted to events occurring while the
virtual machine has virtual dynamic address translation disabled. If you specify
NODAT in addition to DAT, or if you specify neither DAT nor NODAT, events
occurring in both DAT and non-DAT mode are traced.
IDentifier ident
specifies an identifier for a trace trap describing the event. It must be one to
four characters long. If a trap already exists with the given identifier, it is
replaced by the trap for the newly defined event. If you do not specify an ID, a
unique number from 1 to 9999 is assigned as the identifier, with leading zeros
removed. You cannot use the word ALL as an identifier. You may specify the
IDentifier option only when defining a trace trap, not when modifying one with
TRACE TRAP or the TRACE command without a primary trace operand.
CMd cp_command
specifies a CP command or set of CP commands to be processed when the
specified event occurs.
Multiple commands must be separated by line-end characters. Actual line-end
characters end the trace command. For example, if the pound sign (#) is your
logical line-end character, and if the double quotation mark (“) is your logical
escape character, trace svc cmd d 20#d 30 issues a TRACE SVC command
that displays location 20, and then issues DISPLAY to display location 30.
The command trace svc cmd d 20“#d 30 issues one TRACE command; it
displays locations 20 and 30 whenever an SVC instruction is executed.
You can use this option with TRACE GOTO, TRACE CALL, and TRACE
RETURN to allow conditional and unconditional branching and subroutine calls
between trace environments.
All characters between the CMD option and the end of the TRACE command
line are considered part of the CMD field; thus, it must be the last option on the
line. No command syntax verification is made on the set of CP commands to be
processed until the specified event occurs. Terminal output from the set of
commands is not affected by the TERM or NOTERM specification of the trace
event.
NOCMD
specifies that no CP command be run when the specified event occurs. Use
NOCMD to delete CMD fields from existing trace events.
1. Guest control register values and translation table contents define the address
space structure of the virtual machine. Program execution (and the STORE
command) can change that structure over time. The TRACE command
operands that specify a guest address space to be traced by a trace trap use
the current guest control register and translation table values to determine the
segment table origin (STO) of the address space to be traced (at the time the
TRACE command is issued). The STO or ASCE is contained in the trace trap
and can be examined by use of the QUERY TRACE command—that is, you
specify an address space based on the state of your virtual machine at the time
the TRACE command is issued.
2. A trace trap generated with a specific address space specification (STO or
ASCE) always identifies that address space using the STO or ASCE generated
from the control registers, the translation tables, or both.If your program
execution changes the control register values and translation table contents to
represent a different address space structure, there is no change to the trace