configs: Add --enable-dvm CL option to CHI configs

By using the "--enable-dvm" command line option it is possible
to issue DVM messages from Arm CPUs

JIRA: https://gem5.atlassian.net/browse/GEM5-1097

Change-Id: I0a2b683ad3403590515bd406e241b66961cee964
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/57301
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>

configs/ruby/CHI.py

@@ -43,6 +43,7 @@ def define_options(parser):
                         default=None,
                         help="NoC config. parameters and bindings. "
                            "Required for CustomMesh topology")
+    parser.add_argument("--enable-dvm", default=False, action="store_true")
 
 def read_config_file(file):
     ''' Read file as a module and return it '''
@@ -65,6 +66,13 @@ def create_system(options, full_system, system, dma_ports, bootmem,
     if options.num_l3caches < 1:
         m5.fatal('--num-l3caches must be at least 1')
 
+    if full_system and options.enable_dvm:
+        if len(cpus) <= 1:
+            m5.fatal("--enable-dvm can't be used with a single CPU")
+        for cpu in cpus:
+            for decoder in cpu.decoder:
+                decoder.dvm_enabled = True
+
     # read specialized classes from config file if provided
     if options.chi_config:
         chi_defs = read_config_file(options.chi_config)