If an addressing condition is encountered in
accessing any field outside the storage of the virtual
machine during execution of any of the assist
functions, the following action is
access has been made when the condition is
encountered, the execution of the assist ends
with an interruption. For any instructions
assisted, a program interruption takes place,
and instruction execution is suppressed; it is
unpredictable whether a privileged-operation or
an addressing exception is indicated. For the
shadow-table-validation function or the page
fault-reflection function, a program interruption
takes place, and it is unpredictable whether a
page-translation exception or an addressing
exception is indicated. For the supervisor-call
function, it is unpredictable whether an
interruption takes place or a program
interruption takes place with an addressing
exception indicated.
2. If a store access has been made before the
addressing condition is encountered, a program
interruption for an addressing exception is
taken, and instruction execution is terminated.
The detailed descriptions of assist functions do
not explicitly mention addressing conditions that
may occur when an invalid address is assigned to
the workspace. This address is found in
MICWORK, word 3 of the parameter list.
References to the workspace are model-dependent.
The interruptions resulting from addressing
conditions in accessing the workspace are in
addition to those enumerated in the detailed
descriptions of assist functions.
Method of Detailed Description
Chapter 2 contains a detailed description of each
virtual-machine-assist function. Chapter 4 contains
a __
broken down into steps. An alphameric
designation, the priority indicator, appears in
parentheses at the end of each step.
Most steps state the conditions under which
execution of the function ends with that step. If
the conditions for ending execution are met for two
or more steps, execution ends with the step having
the highest priority. The relative priority of two
steps is determined by comparing the numbers and
letters of the priority indicators of those two steps
from left to right to find the first differing position.
When the first differing position contains a
number, the step whose priority indicator has the
lower number has the higher priority. When the
first differing position contains a letter, both steps
are of equal priority.
When two or more steps having the samepriority have their ending conditions satisfied, it is
unpredictable with which of those steps execution
of the function will actually end.
At the end of the detailed description of each
assist function is a summary showing each field of
each control block in storage that is accessed. The
offset shown is the offset to be applied to the
address by which that control block was located.
In general, this is the same as the offset within the
control block. However, the field,VMPSW, is
located at offset A8 hex within theVMBLOK. The offset is shown as zero because that field is
directly located by the contents ofMICVPSW without the application of any additional offset.
Assists for70 7
accessing any field outside the storage of the virtual
machine during execution of any of the assist
functions, the following action is
access has been made when the condition is
encountered, the execution of the assist ends
with an interruption. For any instructions
assisted, a program interruption takes place,
and instruction execution is suppressed; it is
unpredictable whether a privileged-operation or
an addressing exception is indicated. For the
shadow-table-validation function or the page
fault-reflection function, a program interruption
takes place, and it is unpredictable whether a
page-translation exception or an addressing
exception is indicated. For the supervisor-call
function, it is unpredictable whether an
interruption takes place or a program
interruption takes place with an addressing
exception indicated.
2. If a store access has been made before the
addressing condition is encountered, a program
interruption for an addressing exception is
taken, and instruction execution is terminated.
The detailed descriptions of assist functions do
not explicitly mention addressing conditions that
may occur when an invalid address is assigned to
the workspace. This address is found in
MICWORK, word 3 of the parameter list.
References to the workspace are model-dependent.
The interruptions resulting from addressing
conditions in accessing the workspace are in
addition to those enumerated in the detailed
descriptions of assist functions.
Method of Detailed Description
Chapter 2 contains a detailed description of each
virtual-machine-assist function. Chapter 4 contains
a __
broken down into steps. An alphameric
designation, the priority indicator, appears in
parentheses at the end of each step.
Most steps state the conditions under which
execution of the function ends with that step. If
the conditions for ending execution are met for two
or more steps, execution ends with the step having
the highest priority. The relative priority of two
steps is determined by comparing the numbers and
letters of the priority indicators of those two steps
from left to right to find the first differing position.
When the first differing position contains a
number, the step whose priority indicator has the
lower number has the higher priority. When the
first differing position contains a letter, both steps
are of equal priority.
When two or more steps having the same
unpredictable with which of those steps execution
of the function will actually end.
At the end of the detailed description of each
assist function is a summary showing each field of
each control block in storage that is accessed. The
offset shown is the offset to be applied to the
address by which that control block was located.
In general, this is the same as the offset within the
control block. However, the field,
located at offset A8 hex within the
directly located by the contents of
Assists for
