stdlib, configs: stdlib SimPoints support and example scripts

simpoints-se-checkpoint.py & simpoints-se-restore.py:
These are two example scripts to show how to use SimPoints functions with
the stdlib.

se_binary_workload.py:
Allow se_binary_workload to take in SimPoint Class item and schedule
SimPoint exit events.

exit_event.py:
Added SIMPOINT_BEGIN and MAX_INSTS exit events.

simulator.py:
Added SIMPOINT_BEGIN and MAX_INSTS exit event scheduling functions.
They can schedule exit events before or during the simulation.

Jira Issue: https://gem5.atlassian.net/browse/GEM5-1259

Change-Id: Iaa07a83de9dddc293b9f1a230aba8e35d4f5af6c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/63154
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>

src/python/gem5/components/boards/se_binary_workload.py

@@ -26,10 +26,12 @@
 
 from .abstract_board import AbstractBoard
 from ...resources.resource import AbstractResource
+from gem5.utils.simpoint import SimPoint
 
 from m5.objects import SEWorkload, Process
 
 from typing import Optional, List
+from m5.util import warn
 
 
 class SEBinaryWorkload:
@@ -52,6 +54,7 @@ class SEBinaryWorkload:
         exit_on_work_items: bool = True,
         stdin_file: Optional[AbstractResource] = None,
         arguments: List[str] = [],
+        simpoint: SimPoint = None,
     ) -> None:
         """Set up the system to run a specific binary.
 
@@ -60,11 +63,16 @@ class SEBinaryWorkload:
         * Dynamically linked executables are partially supported when the host
           ISA and the simulated ISA are the same.
 
+        **Warning:** SimPoints only works with one core
+
         :param binary: The resource encapsulating the binary to be run.
         :param exit_on_work_items: Whether the simulation should exit on work
         items. True by default.
         :param stdin_file: The input file for the binary
         :param arguments: The input arguments for the binary
+        :param simpoint: The SimPoint object that contains the list of
+        SimPoints starting instructions, the list of weights, and the SimPoints
+        interval
         """
 
         # We assume this this is in a multiple-inheritance setup with an
@@ -87,5 +95,12 @@ class SEBinaryWorkload:
         for core in self.get_processor().get_cores():
             core.set_workload(process)
 
+        if simpoint is not None:
+            if self.get_processor().get_num_cores() > 1:
+                warn("SimPoints only works with one core")
+            self.get_processor().get_cores()[0].set_simpoint(
+                inst_starts=simpoint.get_simpoint_start_insts(), init=True
+            )
+
         # Set whether to exit on work items for the se_workload
         self.exit_on_work_items = exit_on_work_items

src/python/gem5/simulate/exit_event.py

@@ -46,6 +46,8 @@ class ExitEvent(Enum):
     USER_INTERRUPT = (  # An exit due to a user interrupt (e.g., cntr + c)
         "user interupt"
     )
+    SIMPOINT_BEGIN = "simpoint begins"
+    MAX_INSTS = "number of instructions reached"
 
     @classmethod
     def translate_exit_status(cls, exit_string: str) -> "ExitEvent":
@@ -81,6 +83,10 @@ class ExitEvent(Enum):
             return ExitEvent.CHECKPOINT
         elif exit_string == "user interrupt received":
             return ExitEvent.USER_INTERRUPT
+        elif exit_string == "simpoint starting point found":
+            return ExitEvent.SIMPOINT_BEGIN
+        elif exit_string == "a thread reached the max instruction count":
+            return ExitEvent.MAX_INSTS
         raise NotImplementedError(
             "Exit event '{}' not implemented".format(exit_string)
         )

src/python/gem5/simulate/simulator.py

@@ -41,6 +41,7 @@ from .exit_event_generators import (
     default_switch_generator,
     default_workbegin_generator,
     default_workend_generator,
+    default_simpoint_generator,
 )
 from .exit_event import ExitEvent
 from ..components.boards.abstract_board import AbstractBoard
@@ -179,6 +180,8 @@ class Simulator:
             ExitEvent.WORKEND: default_workend_generator(),
             ExitEvent.USER_INTERRUPT: default_exit_generator(),
             ExitEvent.MAX_TICK: default_exit_generator(),
+            ExitEvent.SIMPOINT_BEGIN: default_simpoint_generator(),
+            ExitEvent.MAX_INSTS: default_simpoint_generator(),
         }
 
         if on_exit_event:
@@ -197,6 +200,40 @@ class Simulator:
 
         self._checkpoint_path = checkpoint_path
 
+    def schedule_simpoint(
+        self, simpoint_start_insts: List[int], schedule_at_init: bool = False
+    ) -> None:
+        """
+        Schedule SIMPOINT_BEGIN exit events
+
+        **Warning:** SimPoints only work with one core
+
+        :param simpoint_start_insts: a list of number of instructions
+        indicating the starting point of the simpoints
+        :param schedule_at_init: if it is True, schedule the events in the init
+        stage of the core, else, schedule the events during the simulation
+        """
+        if self._board.get_processor().get_num_cores() > 1:
+            warn("SimPoints only work with one core")
+        self._board.get_processor().get_cores()[0].set_simpoint(
+            simpoint_start_insts, schedule_at_init
+        )
+
+    def schedule_max_insts(
+        self, inst: int, schedule_at_init: bool = False
+    ) -> None:
+        """
+        Schedule a MAX_INSTS exit event when any thread in the current core
+        reaches the given number of instructions
+
+        :param insts: a number of instructions
+        :param schedule_at_init: if it is True, schedule the event in the init
+        stage of the core, else, schedule the event during the simulation
+        """
+        self._board.get_processor().get_cores()[0].set_inst_stop_any_thread(
+            inst, schedule_at_init
+        )
+
     def get_stats(self) -> Dict:
         """
         Obtain the current simulation statistics as a Dictionary, conforming