stdlib: Add warning message for set_workload being called twice (#1571)

This commit adds a warning message for when set_workload is called
twice, as users typically do not mean to do this.

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

@@ -110,6 +110,7 @@ class AbstractBoard:
         # is defined. Whether or not the board is to be run in FS mode is
         # determined by which kind of workload is set.
         self._is_fs = None
+        self._is_workload_set = False
 
         # This variable is used to record the checkpoint directory which is
         # set when declaring the board's workload and then used by the
@@ -211,6 +212,12 @@ class AbstractBoard:
             )
         return self._is_fs
 
+    def set_is_workload_set(self, is_set: bool) -> None:
+        self._is_workload_set = is_set
+
+    def is_workload_set(self) -> bool:
+        return self._is_workload_set
+
     def set_workload(self, workload: WorkloadResource) -> None:
         """
         Set the workload for this board to run.

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

@@ -34,6 +34,7 @@ from typing import (
 )
 
 import m5
+from m5.util import warn
 
 from ...resources.resource import (
     BootloaderResource,
@@ -180,6 +181,10 @@ class KernelDiskWorkload:
         # Abstract board. This function will not work otherwise.
         assert isinstance(self, AbstractBoard)
 
+        if self.is_workload_set():
+            warn("Workload has been set more than once!")
+        self.set_is_workload_set(True)
+
         # Set the disk device
         self._disk_device = disk_device
 

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

@@ -101,6 +101,10 @@ class SEBinaryWorkload:
         # Abstract board. This function will not work otherwise.
         assert isinstance(self, AbstractBoard)
 
+        if self.is_workload_set():
+            warn("Workload has been set more than once!")
+        self.set_is_workload_set(True)
+
         # If we are setting a workload of this type, we need to run as a
         # SE-mode simulation.
         self._set_fullsystem(False)