scons: Update the Kconfig build options

The CL updates the Kconfig:
1. Replace the USE_NULL_ISA with BUILD_ISA
2. The USE_XXX_ISAs are depends on BUILD_ISA
3. If the BUILD_ISA is set, at least one of USE_XXX_ISAs must be set
4. Refactor the USE_KVM option

Change-Id: I2a600dea9fb671263b0191c46c5790ebbe91a7b8

build_opts/ALL

@@ -1,5 +1,6 @@
 RUBY=y
 RUBY_PROTOCOL_MESI_TWO_LEVEL=y
+BUILD_ISA=y
 USE_ARM_ISA=y
 USE_MIPS_ISA=y
 USE_POWER_ISA=y

build_opts/ARM

@@ -1,3 +1,4 @@
+BUILD_ISA=y
 USE_ARM_ISA=y
 RUBY=y
 RUBY_PROTOCOL_CHI=y

build_opts/ARM_MESI_Three_Level

@@ -1,3 +1,4 @@
+BUILD_ISA=y
 USE_ARM_ISA=y
 RUBY=y
 RUBY_PROTOCOL_MESI_THREE_LEVEL=y

build_opts/ARM_MESI_Three_Level_HTM

@@ -1,3 +1,4 @@
+BUILD_ISA=y
 USE_ARM_ISA=y
 RUBY=y
 RUBY_PROTOCOL_MESI_THREE_LEVEL_HTM=y

build_opts/ARM_MOESI_hammer

@@ -1,3 +1,4 @@
+BUILD_ISA=y
 USE_ARM_ISA=y
 RUBY=y
 RUBY_PROTOCOL_MOESI_HAMMER=y

build_opts/GCN3_X86

@@ -1,5 +1,6 @@
 RUBY=y
 RUBY_PROTOCOL_GPU_VIPER=y
+BUILD_ISA=y
 USE_X86_ISA=y
 GCN3_GPU_ISA=y
 BUILD_GPU=y

build_opts/Garnet_standalone

@@ -1,3 +1,2 @@
 RUBY=y
 RUBY_PROTOCOL_GARNET_STANDALONE=y
-USE_NULL_ISA=y

build_opts/MIPS

@@ -1,3 +1,4 @@
 RUBY=y
 RUBY_PROTOCOL_MI_EXAMPLE=y
+BUILD_ISA=y
 USE_MIPS_ISA=y

build_opts/NULL

@@ -1,3 +1,2 @@
 RUBY=y
 RUBY_PROTOCOL_MI_EXAMPLE=y
-USE_NULL_ISA=y

build_opts/NULL_MESI_Two_Level

@@ -1,3 +1,2 @@
 RUBY=y
 RUBY_PROTOCOL_MESI_TWO_LEVEL=y
-USE_NULL_ISA=y

build_opts/NULL_MOESI_CMP_directory

@@ -1,3 +1,2 @@
 RUBY=y
 RUBY_PROTOCOL_MOESI_CMP_DIRECTORY=y
-USE_NULL_ISA=y

build_opts/NULL_MOESI_CMP_token

@@ -1,3 +1,2 @@
 RUBY=y
 RUBY_PROTOCOL_MOESI_CMP_TOKEN=y
-USE_NULL_ISA=y

build_opts/NULL_MOESI_hammer

@@ -1,3 +1,2 @@
 RUBY=y
 RUBY_PROTOCOL_MOESI_HAMMER=y
-USE_NULL_ISA=y

build_opts/POWER

@@ -1,3 +1,4 @@
 RUBY=y
 RUBY_PROTOCOL_MI_EXAMPLE=y
+BUILD_ISA=y
 USE_POWER_ISA=y

build_opts/RISCV

@@ -1,3 +1,4 @@
 RUBY=y
 RUBY_PROTOCOL_MI_EXAMPLE=y
+BUILD_ISA=y
 USE_RISCV_ISA=y

build_opts/SPARC

@@ -1,3 +1,4 @@
 RUBY=y
 RUBY_PROTOCOL_MI_EXAMPLE=y
+BUILD_ISA=y
 USE_SPARC_ISA=y

build_opts/VEGA_X86

@@ -1,5 +1,6 @@
 RUBY=y
 RUBY_PROTOCOL_GPU_VIPER=y
+BUILD_ISA=y
 USE_X86_ISA=y
 VEGA_GPU_ISA=y
 BUILD_GPU=y

build_opts/X86

@@ -1,4 +1,5 @@
 RUBY=y
 NUMBER_BITS_PER_SET=128
 RUBY_PROTOCOL_MESI_TWO_LEVEL=y
+BUILD_ISA=y
 USE_X86_ISA=y

build_opts/X86_MESI_Two_Level

@@ -1,4 +1,5 @@
 RUBY=y
 NUMBER_BITS_PER_SET=128
 RUBY_PROTOCOL_MESI_TWO_LEVEL=y
+BUILD_ISA=y
 USE_X86_ISA=y

build_opts/X86_MI_example

@@ -1,3 +1,4 @@
 RUBY=y
 RUBY_PROTOCOL_MI_EXAMPLE=y
+BUILD_ISA=y
 USE_X86_ISA=y

build_opts/X86_MOESI_AMD_Base

@@ -1,3 +1,4 @@
 RUBY=y
 RUBY_PROTOCOL_MOESI_AMD_BASE=y
+BUILD_ISA=y
 USE_X86_ISA=y

src/arch/Kconfig

@@ -28,10 +28,21 @@ config TARGET_GPU_ISA
 
 rsource "amdgpu/Kconfig"
 
+config BUILD_ISA
+    bool "Build the arch ISA"
+    default n
+
+menu "ISA"
+
+if BUILD_ISA
+
 rsource "arm/Kconfig"
 rsource "mips/Kconfig"
-rsource "null/Kconfig"
 rsource "power/Kconfig"
 rsource "riscv/Kconfig"
 rsource "sparc/Kconfig"
 rsource "x86/Kconfig"
+
+endif
+
+endmenu

src/arch/SConscript

@@ -56,20 +56,17 @@ Import('*')
 #
 #################################################################
 
-if env['CONF']['USE_ARM_ISA']:
-    isa = 'arm'
-elif env['CONF']['USE_MIPS_ISA']:
-    isa = 'mips'
-elif env['CONF']['USE_POWER_ISA']:
-    isa = 'power'
-elif env['CONF']['USE_RISCV_ISA']:
-    isa = 'riscv'
-elif env['CONF']['USE_SPARC_ISA']:
-    isa = 'sparc'
-elif env['CONF']['USE_X86_ISA']:
-    isa = 'x86'
-elif env['CONF']['USE_NULL_ISA']:
-    isa = 'null'
+if env['CONF']['BUILD_ISA']:
+    if (
+        not env['CONF']['USE_ARM_ISA'] and
+        not env['CONF']['USE_MIPS_ISA'] and
+        not env['CONF']['USE_POWER_ISA'] and
+        not env['CONF']['USE_RISCV_ISA'] and
+        not env['CONF']['USE_SPARC_ISA'] and
+        not env['CONF']['USE_X86_ISA']
+    ):
+        error("At least one ISA need to be set")
+
 
 amdgpu_isa = ['gcn3', 'vega']
 

src/arch/null/Kconfig

@@ -1,27 +0,0 @@
-# Copyright 2022 Google LLC
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met: redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer;
-# redistributions in binary form must reproduce the above copyright
-# notice, this list of conditions and the following disclaimer in the
-# documentation and/or other materials provided with the distribution;
-# neither the name of the copyright holders nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-config USE_NULL_ISA
-    bool "Null ISA support"

src/cpu/kvm/Kconfig

@@ -30,5 +30,4 @@ config KVM_ISA
 config USE_KVM
     depends on KVM_ISA != ""
     bool "Enable hardware virtualized (KVM) CPU models"
-    default y if KVM_ISA != ""
-    default n
+    default y

src/cpu/minor/SConscript

@@ -40,7 +40,7 @@
 
 Import('*')
 
-if not env['CONF']['USE_NULL_ISA']:
+if env['CONF']['BUILD_ISA']:
     SimObject('BaseMinorCPU.py', sim_objects=[
         'MinorOpClass', 'MinorOpClassSet', 'MinorFUTiming', 'MinorFU',
         'MinorFUPool', 'BaseMinorCPU'],

src/cpu/o3/SConscript

@@ -30,7 +30,7 @@ import sys
 
 Import('*')
 
-if not env['CONF']['USE_NULL_ISA']:
+if env['CONF']['BUILD_ISA']:
     SimObject('FUPool.py', sim_objects=['FUPool'])
     SimObject('FuncUnitConfig.py', sim_objects=[])
     SimObject('BaseO3CPU.py', sim_objects=['BaseO3CPU'], enums=[

src/cpu/o3/probe/SConscript

@@ -37,7 +37,7 @@
 
 Import('*')
 
-if not env['CONF']['USE_NULL_ISA']:
+if env['CONF']['BUILD_ISA']:
     SimObject('SimpleTrace.py', sim_objects=['SimpleTrace'])
     Source('simple_trace.cc')
     DebugFlag('SimpleTrace')

src/cpu/simple/SConscript

@@ -28,7 +28,7 @@
 
 Import('*')
 
-if not env['CONF']['USE_NULL_ISA']:
+if env['CONF']['BUILD_ISA']:
     SimObject('BaseAtomicSimpleCPU.py', sim_objects=['BaseAtomicSimpleCPU'])
     Source('atomic.cc')
 

src/cpu/simple/probes/SConscript

@@ -28,6 +28,6 @@
 
 Import('*')
 
-if not env['CONF']['USE_NULL_ISA']:
+if env['CONF']['BUILD_ISA']:
     SimObject('SimPoint.py', sim_objects=['SimPoint'])
     Source('simpoint.cc')

src/python/gem5/runtime.py

@@ -42,6 +42,9 @@ def get_supported_isas() -> Set[ISA]:
     """
     supported_isas = set()
 
+    if not buildEnv["BUILD_ISA"]:
+        return {ISA.NULL}
+
     if "TARGET_ISA" in buildEnv.keys():
         supported_isas.add(get_isa_from_str(buildEnv["TARGET_ISA"]))