diff --git a/hypervisor/Makefile b/hypervisor/Makefile
index 86f68ee18..cd49ae28c 100644
--- a/hypervisor/Makefile
+++ b/hypervisor/Makefile
@@ -433,7 +433,7 @@ $(HV_ACPI_TABLE_TIMESTAMP): $(HV_CONFIG_TIMESTAMP)
 	python3 ../misc/config_tools/acpi_gen/bin_gen.py --board $(HV_BOARD_XML) --scenario $(HV_SCENARIO_XML) --asl $(HV_CONFIG_DIR) --out $(HV_OBJDIR) --iasl_path $(ASL_COMPILER) --iasl_min_ver $(IASL_MIN_VER)
 	@touch $(HV_ACPI_TABLE_TIMESTAMP)
 
-$(SERIAL_CONF): $(HV_CONFIG_TIMESTAMP)
+$(SERIAL_CONF): $(HV_CONFIG_TIMESTAMP) $(HV_ALLOCATION_XML)
 	@echo "generate the serial configuration file for service VM ..."
 	python3 ../misc/config_tools/service_vm_config/serial_config.py --allocation $(HV_ALLOCATION_XML) --scenario $(HV_SCENARIO_XML) --out $(SERIAL_CONF)
 
diff --git a/hypervisor/scripts/genconf.sh b/hypervisor/scripts/genconf.sh
index dfdd7a222..c9efbcc93 100644
--- a/hypervisor/scripts/genconf.sh
+++ b/hypervisor/scripts/genconf.sh
@@ -22,12 +22,11 @@ apply_patch () {
 tool_dir=${base_dir}/../misc/config_tools
 diffconfig_list=${out}/.diffconfig
 
-python3 ${tool_dir}/scenario_config/validator.py ${board_xml} ${scenario_xml} &&
 python3 ${tool_dir}/board_config/board_cfg_gen.py --board ${board_xml} --scenario ${scenario_xml} --out ${out} &&
 python3 ${tool_dir}/acpi_gen/asl_gen.py --board ${board_xml} --scenario ${scenario_xml} --out ${out}
-
-if [ $? -ne 0 ]; then
-    exit $?
+exitcode=$?
+if [ $exitcode -ne 0 ]; then
+    exit $exitcode
 fi
 
 if ! which xsltproc ; then
diff --git a/hypervisor/scripts/makefile/config.mk b/hypervisor/scripts/makefile/config.mk
index 26854e464..63fb88b12 100644
--- a/hypervisor/scripts/makefile/config.mk
+++ b/hypervisor/scripts/makefile/config.mk
@@ -127,7 +127,8 @@ HV_ALLOCATION_XML := $(HV_CONFIG_DIR)/allocation.xml
 HV_UNIFIED_XML := $(HV_CONFIG_DIR)/unified.xml
 HV_CONFIG_H := $(HV_OBJDIR)/include/config.h
 HV_CONFIG_MK := $(HV_CONFIG_DIR)/config.mk
-HV_CONFIG_TIMESTAMP := $(HV_CONFIG_DIR)/.timestamp
+HV_VALIDATION_TIMESTAMP := $(HV_CONFIG_DIR)/.validation.timestamp
+HV_CONFIG_TIMESTAMP := $(HV_CONFIG_DIR)/.configfiles.timestamp
 HV_DIFFCONFIG_LIST := $(HV_CONFIG_DIR)/.diffconfig
 
 # Directory containing generated configuration sources for diffconfig
@@ -219,7 +220,7 @@ $(HV_SCENARIO_XML):
 
 # A unified XML is generated to include board and scenario XML files so that XSLT scripts have access to both for
 # generating source files.
-$(HV_ALLOCATION_XML): $(HV_BOARD_XML) $(HV_SCENARIO_XML) | $(HV_CONFIG_DIR)
+$(HV_ALLOCATION_XML): $(HV_BOARD_XML) $(HV_SCENARIO_XML) $(HV_VALIDATION_TIMESTAMP) | $(HV_CONFIG_DIR)
 	@python3 $(HV_CONFIG_TOOL_DIR)/static_allocators/main.py --board $(HV_BOARD_XML) --scenario $(HV_SCENARIO_XML) --output $(HV_ALLOCATION_XML)
 	@echo "$@ generated"
 
@@ -238,7 +239,12 @@ $(HV_CONFIG_H): $(HV_UNIFIED_XML)
 	@xsltproc -o $@ --xinclude --xincludestyle $(HV_CONFIG_XFORM_DIR)/config.h.xsl $<
 	@echo "$@ generated"
 
-$(HV_CONFIG_TIMESTAMP): $(HV_UNIFIED_XML) ${HV_DIFFCONFIG_LIST} | $(HV_CONFIG_DIR)
+$(HV_VALIDATION_TIMESTAMP): $(HV_BOARD_XML) $(HV_SCENARIO_XML) | $(HV_CONFIG_DIR)
+	@echo "Validating scenario configurations..."
+	@python3 $(HV_CONFIG_TOOL_DIR)/scenario_config/validator.py $(HV_BOARD_XML) $(HV_SCENARIO_XML)
+	@touch $@
+
+$(HV_CONFIG_TIMESTAMP): $(HV_VALIDATION_TIMESTAMP) $(HV_UNIFIED_XML) ${HV_DIFFCONFIG_LIST} | $(HV_CONFIG_DIR)
 	@sh $(BASEDIR)/scripts/genconf.sh $(BASEDIR) $(HV_BOARD_XML) $(HV_SCENARIO_XML) $(HV_CONFIG_DIR) $(HV_UNIFIED_XML)
 	@touch $@
 
@@ -287,7 +293,7 @@ else
   endif
 endif
 
-$(HV_DIFFCONFIG_LIST):
+$(HV_DIFFCONFIG_LIST): | $(HV_CONFIG_DIR)
 	@touch $@
 
 menuconfig: