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

Usage Notes
ASNasn
specifies that an address space number (ASN) is to be used to locate the
address space to be traced. The specified ASN may be one to four
hexadecimal digits long. The ASN is used in conjunction with guest ASN
translation tables to locate the STO of the address space to be traced.
AREGareg
specifies that access register translation is to be used to locate the address
space to be traced. The access register (areg) is specified as one hexadecimal
or two decimal digits. The ALET contained within the access register is used in
conjunction with the guest access register-translation tables to locate the STO
of the address space to be traced.
ALEThexword
specifies that access register translation is to be used to locate the address
space to be traced. The ALET is used in conjunction with the guest access
register-translation tables to locate the STO of the address space to be traced.
ALEThexword.ALraddr
restricts tracing to events in an address space using the specified access list
entry token (ALET) and access list (AL). The ALET and AL are used in
conjunction with the guest access register-translation tables to locate the STO
of the address space to be traced.
INTO range
permits a trap to be taken if the destination of a successful branch instruction is
within the specified range.
You may specify the range as a single address or a pair of addresses
separated by a period (.) or a dash. (–). A dash denotes a starting and ending
range; a period denotes a starting range for a byte count. A branch destination
is considered to be within the range if any byte is within the range.
The addresses are real or virtual as determined by the setting of the dynamic
address translation (DAT) bit in the PSW at the time the event is detected. For
BRANCH tracing, the address or range of addresses can be odd or outside of
the address space; the event is detected after the branch instruction, but before
any attempt is made to fetch the next instruction.
options
For an explanation of options, see “TRACE: Options” on page 1604.
TRACE BRANCH
1. Your virtual machine runs very slowly after you enter the TRACE BRANCH
instruction.
2. While TRACE BRANCH is active, a record of branch instructions is maintained
in the traceback table. You can use the TRACE TABLE command to display the
traceback table.
3. 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 is contained in the trace trap and can be
examined using the QUERY TRACE command—that is, you specify an address
space based on the state of your virtual machine at the time of the TRACE
command that establishes the trace trap.
Chapter 2. CP Commands 1625