tests/vm: check for Python YAML parser in the Makefile

No need to do it in the configure file if it is only used for a help message.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -959,13 +959,6 @@ do
     fi
 done
 
-# Check for existence of python3 yaml, needed to
-# import yaml config files into vm-build.
-python_yaml="no"
-if $(python3 -c "import yaml" 2> /dev/null); then
-    python_yaml="yes"
-fi
-
 : ${smbd=${SMBD-/usr/sbin/smbd}}
 
 # Default objcc to clang if available, otherwise use CC
@@ -6844,7 +6837,6 @@ if test "$docs" != "no"; then
     echo "sphinx-build      $sphinx_build"
 fi
 echo "genisoimage       $genisoimage"
-echo "python_yaml       $python_yaml"
 echo "slirp support     $slirp $(echo_version $slirp $slirp_version)"
 if test "$slirp" != "no" ; then
     echo "smbd              $smbd"
@@ -7945,7 +7937,6 @@ echo "PYTHON=$python" >> $config_host_mak
 echo "SPHINX_BUILD=$sphinx_build" >> $config_host_mak
 echo "SPHINX_WERROR=$sphinx_werror" >> $config_host_mak
 echo "GENISOIMAGE=$genisoimage" >> $config_host_mak
-echo "PYTHON_YAML=$python_yaml" >> $config_host_mak
 echo "CC=$cc" >> $config_host_mak
 if $iasl -h > /dev/null 2>&1; then
   echo "IASL=$iasl" >> $config_host_mak

tests/vm/Makefile.include

@@ -17,6 +17,10 @@ IMAGE_FILES := $(patsubst %, $(IMAGES_DIR)/%.img, $(IMAGES))
 
 .PRECIOUS: $(IMAGE_FILES)
 
+ifneq ($(PYTHON),)
+HAVE_PYTHON_YAML = $(shell $(PYTHON) -c "import yaml" 2> /dev/null && echo yes)
+endif
+
 # 'vm-help' target was historically named 'vm-test'
 vm-help vm-test:
 	@echo "vm-help: Test QEMU in preconfigured virtual machines"
@@ -56,7 +60,7 @@ endif
 	@echo "    QEMU_LOCAL=1                 - Use QEMU binary local to this build."
 	@echo "    QEMU=/path/to/qemu		 - Change path to QEMU binary"
 	@echo "    QEMU_IMG=/path/to/qemu-img	 - Change path to qemu-img tool"
-ifeq ($(PYTHON_YAML),yes)
+ifeq ($(HAVE_PYTHON_YAML),yes)
 	@echo "    QEMU_CONFIG=/path/conf.yml   - Change path to VM configuration .yml file."
 else
 	@echo "    (install python3-yaml to enable support for yaml file to configure a VM.)"