[PATCH v2 10/14] tests/vm: Add ability to select QEMU from current build.

[Robert Foley <robert.foley@linaro.org>]

Added a new special variable QEMU_LOCAL=1, which
will indicate to take the QEMU binary from the current
build.

Signed-off-by: Robert Foley <robert.foley@linaro.org>
---
 tests/vm/Makefile.include |  4 ++++
 tests/vm/basevm.py        | 29 ++++++++++++++++++++++++-----
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/tests/vm/Makefile.include b/tests/vm/Makefile.include
index d1444c99f5..7557c154a1 100644
--- a/tests/vm/Makefile.include
+++ b/tests/vm/Makefile.include
@@ -35,6 +35,7 @@ vm-help vm-test:
 	@echo "    BOOT_CONSOLE=1        	 - Show the console output at boot time. "
 	@echo "    LOG_CONSOLE=1        	 - Log console to file in: ~/.cache/qemu-vm "
 	@echo "    V=1				 - Enable verbose ouput on host and guest commands"
+	@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"
 	@echo "    QEMU_CONFIG=/path/conf.yml   - Change path to VM configuration .yml file."
@@ -54,6 +55,7 @@ $(IMAGES_DIR)/%.img:	$(SRC_PATH)/tests/vm/% \
 		$(if $(V)$(DEBUG), --debug) \
 		$(if $(LOG_CONSOLE),--log-console) \
 		$(if $(BOOT_CONSOLE),--boot-console) \
+		--build-path $(BUILD_DIR)\
 		--image "$@" \
 		--force \
 		--build-image $@, \
@@ -70,6 +72,7 @@ vm-build-%: $(IMAGES_DIR)/%.img
 		$(if $(V),--verbose) \
 		$(if $(LOG_CONSOLE),--log-console) \
 		$(if $(BOOT_CONSOLE),--boot-console) \
+		--build-path $(BUILD_DIR)\
 		--image "$<" \
 		$(if $(BUILD_TARGET),--build-target $(BUILD_TARGET)) \
 		--snapshot \
@@ -92,6 +95,7 @@ vm-boot-ssh-%: $(IMAGES_DIR)/%.img
 		$(if $(J),--jobs $(J)) \
 		$(if $(LOG_CONSOLE),--log-console) \
 		$(if $(BOOT_CONSOLE),--boot-console) \
+		--build-path $(BUILD_DIR)\
 		--image "$<" \
 		--interactive \
 		false, \
diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py
index dc94d1988e..a30a641a4a 100644
--- a/tests/vm/basevm.py
+++ b/tests/vm/basevm.py
@@ -89,9 +89,9 @@ class BaseVM(object):
     # since we found we need to wait more than twice as long.
     tcg_ssh_timeout_multiplier = 4
     def __init__(self, debug=False, vcpus=None, config=None,
-                 log_console=False,
-                 boot_console=None):
+                 log_console=False, boot_console=False, build_path=None):
         self._guest = None
+        self._build_path = build_path
         self._boot_console = boot_console
         # Allow input config to override defaults.
         self._config = DEFAULT_CONFIG.copy()
@@ -273,8 +273,8 @@ class BaseVM(object):
         args += self._data_args + extra_args + self._config['extra_args']
         args += ["-device", "VGA"]
         logging.debug("QEMU args: %s", " ".join(args))
-        qemu_bin = os.environ.get("QEMU", "qemu-system-" + self.arch)
-        guest = QEMUMachine(binary=qemu_bin, args=args,
+        qemu_path = get_qemu_path(self.arch, self._build_path)
+        guest = QEMUMachine(binary=qemu_path, args=args,
                             console_log=self._console_log_path)
         guest.set_machine(self._config['machine'])
         guest.set_console()
@@ -479,6 +479,22 @@ class BaseVM(object):
                                stderr=self._stdout)
         return os.path.join(cidir, "cloud-init.iso")
 
+def get_qemu_path(arch, build_path=None):
+    """Fetch the path to the qemu binary."""
+    qemu_local = os.environ.get("QEMU_LOCAL", 0)
+    # If QEMU environment variable set, it takes precedence
+    if "QEMU" in os.environ:
+        qemu_path = os.environ["QEMU"]
+    elif qemu_local:
+        if not build_path:
+            raise Exception("--build-path option required with QEMU_LOCAL")
+        qemu_path = os.path.join(build_path, arch + "-softmmu")
+        qemu_path = os.path.join(qemu_path, "qemu-system-" + arch)
+    else:
+        # Default is to use system path for qemu.
+        qemu_path = "qemu-system-" + arch
+    return qemu_path
+
 def parse_config(config, args):
     """ Parse yaml config and populate our config structure.
         The yaml config allows the user to override the
@@ -543,6 +559,8 @@ def parse_args(vmcls):
                            "See config_example.yaml for example.")
     parser.add_option("--boot-console", action="store_true",
                       help="Show console during boot. ")
+    parser.add_option("--build-path", default=None,
+                      help="Path of build directory. ")
     parser.disable_interspersed_args()
     return parser.parse_args()
 
@@ -559,7 +577,8 @@ def main(vmcls, config=None):
                                    else logging.WARN))
         vm = vmcls(debug=args.debug, vcpus=args.jobs, config=config,
                    log_console=args.log_console,
-                   boot_console=args.boot_console)
+                   boot_console=args.boot_console,
+                   build_path=args.build_path)
         if args.build_image:
             if os.path.exists(args.image) and not args.force:
                 sys.stderr.writelines(["Image file exists: %s\n" % args.image,
-- 
2.17.1