[PATCH v4 03/10] tests/vm: Added configuration file support

[Robert Foley]

Changes to tests/vm/basevm.py to allow accepting a configuration file
as a parameter. Allows for specifying VM options such as
cpu, machine, memory, and arbitrary qemu arguments for specifying options
such as NUMA configuration.
Also added an example conf_example_aarch64.yml and conf_example_x86.yml.

Signed-off-by: Robert Foley <address@hidden>
---
 configure                         |  9 ++++++
 tests/vm/Makefile.include         |  6 ++++
 tests/vm/basevm.py                | 40 +++++++++++++++++++++++-
 tests/vm/conf_example_aarch64.yml | 51 +++++++++++++++++++++++++++++++
 tests/vm/conf_example_x86.yml     | 50 ++++++++++++++++++++++++++++++
 5 files changed, 155 insertions(+), 1 deletion(-)
 create mode 100644 tests/vm/conf_example_aarch64.yml
 create mode 100644 tests/vm/conf_example_x86.yml

diff --git a/configure b/configure
index 3c7470096f..739cde2318 100755
--- a/configure
+++ b/configure
@@ -947,6 +947,13 @@ 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
@@ -6584,6 +6591,7 @@ 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              $smbd"
@@ -7634,6 +7642,7 @@ echo "INSTALL_LIB=$install -c -m 0644" >> $config_host_mak
 echo "PYTHON=$python" >> $config_host_mak
 echo "SPHINX_BUILD=$sphinx_build" >> $config_host_mak
 echo "GENISOIMAGE=$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" >> $config_host_mak
diff --git a/tests/vm/Makefile.include b/tests/vm/Makefile.include
index 1bf9693d19..78a2de1f82 100644
--- a/tests/vm/Makefile.include
+++ b/tests/vm/Makefile.include
@@ -43,6 +43,12 @@ endif
        @echo "    V=1                           - Enable verbose ouput on host 
and guest commands"
        @echo "    QEMU=/path/to/qemu            - Change path to QEMU binary"
        @echo "    QEMU_IMG=/path/to/qemu-img    - Change path to qemu-img tool"
+ifeq ($(PYTHON_YAML),yes)
+       @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.)"
+endif
+       @echo "                                   See conf_example_*.yml for 
file format details."
 
 vm-build-all: $(addprefix vm-build-, $(IMAGES))
 
diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py
index 97c6f625c9..dd545d3d1d 100644
--- a/tests/vm/basevm.py
+++ b/tests/vm/basevm.py
@@ -461,9 +461,43 @@ class BaseVM(object):
                                cwd=cidir,
                                stdin=self._devnull, stdout=self._stdout,
                                stderr=self._stdout)
-
         return os.path.join(cidir, "cloud-init.iso")
 
+def parse_config(config, args):
+    """ Parse yaml config and populate our config structure.
+        The yaml config allows the user to override the
+        defaults for VM parameters.  In many cases these
+        defaults can be overridden without rebuilding the VM."""
+    if args.config:
+        config_file = args.config
+    elif 'QEMU_CONFIG' in os.environ:
+        config_file = os.environ['QEMU_CONFIG']
+    else:
+        return config
+    if not os.path.exists(config_file):
+        raise Exception("config file {} does not exist".format(config_file))
+    # We gracefully handle importing the yaml module
+    # since it might not be installed.
+    # If we are here it means the user supplied a .yml file,
+    # so if the yaml module is not installed we will exit with error.
+    try:
+        import yaml
+    except ImportError:
+        print("The python3-yaml package is needed "\
+              "to support config.yaml files")
+        # Instead of raising an exception we exit to avoid
+        # a raft of messy (expected) errors to stdout.
+        exit(1)
+    with open(config_file) as f:
+        yaml_dict = yaml.safe_load(f)
+
+    if 'qemu-conf' in yaml_dict:
+        config.update(yaml_dict['qemu-conf'])
+    else:
+        raise Exception("config file {} is not valid"\
+                        " missing qemu-conf".format(config_file))
+    return config
+
 def parse_args(vmcls):
 
     def get_default_jobs():
@@ -498,6 +532,9 @@ def parse_args(vmcls):
                       help="Interactively run command")
     parser.add_option("--snapshot", "-s", action="store_true",
                       help="run tests with a snapshot")
+    parser.add_option("--config", "-c", default=None,
+                      help="Provide config yaml for configuration. "\
+                           "See config_example.yaml for example.")
     parser.disable_interspersed_args()
     return parser.parse_args()
 
@@ -509,6 +546,7 @@ def main(vmcls, config=None):
         if not argv and not args.build_qemu and not args.build_image:
             print("Nothing to do?")
             return 1
+        config = parse_config(config, args)
         logging.basicConfig(level=(logging.DEBUG if args.debug
                                    else logging.WARN))
         vm = vmcls(debug=args.debug, vcpus=args.jobs, config=config)
diff --git a/tests/vm/conf_example_aarch64.yml 
b/tests/vm/conf_example_aarch64.yml
new file mode 100644
index 0000000000..9d44ae356f
--- /dev/null
+++ b/tests/vm/conf_example_aarch64.yml
@@ -0,0 +1,51 @@
+#
+# Example yaml for use by any of the scripts in tests/vm.
+# Can be provided as an environment variable QEMU_CONFIG
+#
+qemu-conf:
+
+    # If any of the below are not provided, we will just use the qemu defaults.
+
+    # Login username and password(has to be sudo enabled)
+    guest_user: qemu
+    guest_pass: "qemupass"
+
+    # Password for root user can be different from guest.
+    root_pass: "qemupass"
+
+    # If one key is provided, both must be provided.
+    #ssh_key: /complete/path/of/your/keyfile/id_rsa
+    #ssh_pub_key: /complete/path/of/your/keyfile/id_rsa.pub
+
+    cpu: max
+    machine: virt,gic-version=max
+    memory: 16G
+
+    # The below is a example for how to configure NUMA topology with
+    # 4 NUMA nodes and 2 different NUMA distances.
+    qemu_args: "-smp cpus=16,sockets=2,cores=8
+                -numa node,cpus=0-3,nodeid=0 -numa node,cpus=4-7,nodeid=1
+                -numa node,cpus=8-11,nodeid=2 -numa node,cpus=12-15,nodeid=3
+                -numa dist,src=0,dst=1,val=15 -numa dist,src=2,dst=3,val=15
+                -numa dist,src=0,dst=2,val=20 -numa dist,src=0,dst=3,val=20
+                -numa dist,src=1,dst=2,val=20 -numa dist,src=1,dst=3,val=20"
+
+    # By default we do not set the DNS.
+    # You override the defaults by setting the below.
+    #dns: 1.234.567.89
+
+    # By default we will use a "block" device, but
+    # you can also boot from a "scsi" device.
+    # Just keep in mind your scripts might need to change
+    # As you will have /dev/sda instead of /dev/vda (for block device)
+    boot_dev_type: "block"
+
+    # By default the ssh port is not fixed.
+    # A fixed ssh port makes it easier for automated tests.
+    #ssh_port: 5555
+
+    # To install a different set of packages, provide a command to issue
+    #install_cmds: "apt-get update ; apt-get build-dep -y qemu"
+
+    # Or to skip the install entirely, just provide ""
+    #install_cmds: ""
diff --git a/tests/vm/conf_example_x86.yml b/tests/vm/conf_example_x86.yml
new file mode 100644
index 0000000000..78d3f5830f
--- /dev/null
+++ b/tests/vm/conf_example_x86.yml
@@ -0,0 +1,50 @@
+#
+# Example yaml for use by any of the x86 based scripts in tests/vm.
+# Can be provided as an environment variable QEMU_CONFIG
+#
+qemu-conf:
+
+    # If any of the below are not provided, we will just use the qemu defaults.
+
+    # Login username and password(has to be sudo enabled)
+    guest_user: "qemu"
+    guest_pass: "qemupass"
+
+    # Password for root user can be different from guest.
+    root_pass: "qemupass"
+
+    # Provide default ssh keys of current user.
+    # You need to edit the below for your user.
+    #ssh_key_file: /home/<user>/.ssh/id_rsa
+    #ssh_pub_key_file: /home/<user>/.ssh/id_rsa.pub
+
+    cpu: max
+    machine: pc
+    memory: 8G
+
+    # The below is a example for how to configure NUMA topology with
+    # 4 NUMA nodes and 2 different NUMA distances.
+    qemu_args: "-smp cpus=8,sockets=2,cores=4
+                -object 
memory-backend-ram,size=4G,policy=bind,host-nodes=0,id=ram-node0
+                -object 
memory-backend-ram,size=4G,policy=bind,host-nodes=0,id=ram-node1
+                -object 
memory-backend-ram,size=4G,policy=bind,host-nodes=1,id=ram-node2
+                -object 
memory-backend-ram,size=4G,policy=bind,host-nodes=1,id=ram-node3
+                -numa node,cpus=0-1,nodeid=0 -numa node,cpus=2-3,nodeid=1
+                -numa node,cpus=4-5,nodeid=2 -numa node,cpus=6-7,nodeid=3
+                -numa dist,src=0,dst=1,val=15 -numa dist,src=2,dst=3,val=15
+                -numa dist,src=0,dst=2,val=20 -numa dist,src=0,dst=3,val=20
+                -numa dist,src=1,dst=2,val=20 -numa dist,src=1,dst=3,val=20"
+
+    # By default we do not set the DNS.
+    # You override the defaults by setting the below.
+    #dns: "1.234.567.89"
+
+    # By default we will use a "block" device, but
+    # you can also boot from a "scsi" device.
+    # Just keep in mind your scripts might need to change
+    # As you will have /dev/sda instead of /dev/vda (for block device)
+    boot_dev_type: "block"
+
+    # By default the ssh port is not fixed.
+    # A fixed ssh port makes it easier for automated tests.
+    ssh_port: 5555
-- 
2.17.1