multi_vms_with_stress: New case to test multiple VMs with stressing

New a case to test multiple VMs under running stress on host.
Signed-off-by: NYongxue Hong <yhong@redhat.com>

qemu/tests/cfg/multi_vms_with_stress.cfg

+- multi_vms_with_stress:
+    virt_test_type = qemu
+    type = multi_vms_with_stress
+    kill_vm = yes
+    start_vm = no
+    not_preprocess = yes
+    vms += " vm2 vm3 vm4 vm5"
+    mem = 4G
+    vm_mem_minimum = ${mem}
+    stress_inst_dir = /tmp/stress
+    stress_ver = stress-1.0.4
+    stress_pkg_name = ${stress_ver}.tar.gz
+    stress_bin = ${stress_inst_dir}/${stress_ver}/bin/stress
+    stress_cmd = ${stress_bin} --cpu 4 --io 4 --vm 2 --vm-bytes 128M &
+    pre_command = "mkdir -p ${stress_inst_dir}"
+    post_command = "killall -9 stress; rm -rf ${stress_inst_dir}"

qemu/tests/multi_vms_with_stress.py

+import logging
+import os
+import re
+import shutil
+
+from avocado.utils import process
+
+from virttest import data_dir
+from virttest import env_process
+from virttest import error_context
+from virttest import qemu_storage
+from virttest import utils_misc
+
+
+@error_context.context_aware
+def run(test, params, env):
+    """
+    Test multiple VMs during host is under high stress.
+    Steps:
+        1. Run a stress test on host.
+        2. Start multiple VMs on host and check if all can start
+           successfully.
+        3. Shutdown all VMs.
+
+    :param test: QEMU test object.
+    :param params: Dictionary with the test parameters.
+    :param env: Dictionary with test environment.
+    """
+    def unpack_stress_pkg():
+        """Unpack the stress package."""
+        process.system("tar -xzvf %s -C %s" % (archive_path, stress_inst_dir))
+
+    def install_stress_pkg():
+        """Install the stress package."""
+        cmd_configure = "cd {0} && ./configure --prefix={0}".format(
+            os.path.join(stress_inst_dir, params['stress_ver']))
+        cmd_make = "make && make install"
+        process.system(" && ".join((cmd_configure, cmd_make)), shell=True)
+
+    def run_stress_background():
+        """Run stress in background."""
+        process.system(
+            params['stress_cmd'], shell=True, ignore_bg_processes=True)
+
+    def is_stress_alive():
+        """Whether the stress process is alive."""
+        cmd = 'pgrep -xl stress'
+        if not utils_misc.wait_for(lambda: re.search(
+                r'\d+\s+stress', process.system_output(
+                        cmd, ignore_status=True).decode()), 10):
+            test.error("The stress process is not alive.")
+
+    def copy_base_vm_image():
+        """Copy the base vm image for VMs."""
+        src_img = qemu_storage.QemuImg(
+            params, data_dir.get_data_dir(), params['images'])
+        src_filename = src_img.image_filename
+        src_format = src_img.image_format
+        dst_dir = os.path.dirname(src_filename)
+        for vm_name in vms_list:
+            dst_filename = os.path.join(
+                dst_dir, '%s.%s' % (vm_name, src_format))
+            logging.info('Copying %s to %s.', src_filename, dst_filename)
+            shutil.copy(src_filename, dst_filename)
+
+    def configure_images_copied():
+        """Configure the images copied for VMs."""
+        for vm_name in vms_list:
+            params['images_%s' % vm_name] = vm_name
+            image_name = 'image_name_{0}_{0}'.format(vm_name)
+            params[image_name] = 'images/%s' % vm_name
+            params['remove_image_%s' % vm_name] = 'yes'
+
+    def wait_for_login_all_vms():
+        """Wait all VMs to login."""
+        return [vm.wait_for_login() for vm in vms]
+
+    def wait_for_shutdown_all_vms(vms, sessions):
+        """Wait all VMs to shutdown."""
+        for vm, session in zip(vms, sessions):
+            logging.info('Shutting down %s.', vm.name)
+            session.sendline(params["shutdown_command"])
+            if not vm.wait_for_shutdown():
+                test.fail("Failed to shutdown %s." % vm.name)
+
+    vms_list = params['vms'].split()[1:]
+    copy_base_vm_image()
+    configure_images_copied()
+
+    stress_inst_dir = params['stress_inst_dir']
+    stress_deps_dir = data_dir.get_deps_dir('stress')
+    archive_path = os.path.join(stress_deps_dir, params['stress_pkg_name'])
+
+    unpack_stress_pkg()
+    install_stress_pkg()
+    run_stress_background()
+    is_stress_alive()
+
+    params['start_vm'] = 'yes'
+    env_process.process(test, params, env,
+                        env_process.preprocess_image,
+                        env_process.preprocess_vm)
+    vms = env.get_all_vms()
+    for vm in vms:
+        vm.verify_alive()
+    wait_for_shutdown_all_vms(vms, wait_for_login_all_vms())