[V2,2/2] tests/vhost_qemu_mtu: add new testsuite vhost_qemu_mtu

diff --git a/tests/TestSuite_vhost_qemu_mtu.py b/tests/TestSuite_vhost_qemu_mtu.py
new file mode 100644
index 00000000..a71b7b6e
--- /dev/null
+++ b/tests/TestSuite_vhost_qemu_mtu.py
@@ -0,0 +1,116 @@ 
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2022 Intel Corporation
+#
+
+import re
+
+import framework.utils as utils
+from framework.pmd_output import PmdOutput
+from framework.test_case import TestCase
+from framework.virt_common import VM
+
+
+class TestVhostQemuMTU(TestCase):
+    def set_up_all(self):
+        self.dut_ports = self.dut.get_ports()
+        self.ports_socket = self.dut.get_numa_id(self.dut_ports[0])
+        self.cores_list = self.dut.get_core_list("all", socket=self.ports_socket)
+        self.verify(
+            len(self.cores_list) >= 4,
+            "There has not enough cores to test this suite %s" % self.suite_name,
+        )
+        self.vhost_core_list = self.cores_list[0:2]
+        self.vm_num = 1
+        self.base_dir = self.dut.base_dir.replace("~", "/root")
+        self.vhost_user = self.dut.new_session(suite="vhost-user")
+        self.vhost_user_pmd = PmdOutput(self.dut, self.vhost_user)
+
+    def set_up(self):
+        """
+        run before each test case.
+        """
+        self.dut.send_expect("rm -rf %s/vhost-net*" % self.base_dir, "#")
+        self.dut.send_expect("killall -s INT dpdk-testpmd", "#")
+        self.dut.send_expect("killall -s INT qemu-system-x86_64", "#")
+        self.vm_dut = []
+        self.vm = []
+
+    def start_vhost_testpmd(self):
+        """
+        start testpmd on vhost
+        """
+        vdevs = ["net_vhost0,iface=vhost-net0,queues=1"]
+        ports = [self.dut.ports_info[self.dut_ports[0]]["pci"]]
+        param = "--txd=512 --rxd=128 --nb-cores=1 --port-topology=chained"
+        self.vhost_user_pmd.start_testpmd(
+            cores=self.vhost_core_list,
+            param=param,
+            vdevs=vdevs,
+            ports=ports,
+            prefix="vhost-user",
+        )
+        self.vhost_user_pmd.execute_cmd("set fwd mac")
+        self.vhost_user_pmd.execute_cmd("start")
+
+    def start_vms(self, vm_config="vhost_sample", mtu=9000):
+        """
+        start two VM, each VM has one virtio device
+        """
+        for i in range(self.vm_num):
+            vm_dut = None
+            vm_info = VM(self.dut, "vm%d" % i, vm_config)
+            vm_params = {}
+            vm_params["driver"] = "vhost-user"
+            vm_params["opt_path"] = self.base_dir + "/vhost-net%d" % i
+            vm_params["opt_mac"] = "52:54:00:00:00:0%d" % (i + 1)
+            vm_params["opt_settings"] = "mrg_rxbuf=on,host_mtu=%d" % mtu
+            vm_info.set_vm_device(**vm_params)
+            try:
+                vm_dut = vm_info.start(set_target=False)
+                if vm_dut is None:
+                    raise Exception("Set up VM ENV failed")
+            except Exception as e:
+                print(utils.RED("Failure for %s" % str(e)))
+            self.verify(vm_dut is not None, "start vm failed")
+            self.vm_dut.append(vm_dut)
+            self.vm.append(vm_info)
+
+    def check_mtu_value_in_vm(self, mtu):
+        vm1_intf = self.vm_dut[0].ports_info[0]["intf"]
+        out = self.vm_dut[0].send_expect("ifconfig %s" % vm1_intf, "#", 10)
+        self.verify("mtu %d" % mtu in out, "Check MTU value in VM FAILED!")
+
+    def check_mtu_value_in_testpmd(self, mtu):
+        out = self.vhost_user_pmd.execute_cmd("show port info 1")
+        self.verify("MTU: %d" % mtu in out, "Check MTU value in testpmd FAILED!")
+
+    def stop_all_apps(self):
+        for i in range(len(self.vm)):
+            self.vm[i].stop()
+            self.vm_dut.remove(self.vm_dut[i])
+            self.vm.remove(self.vm[i])
+        self.vhost_user_pmd.quit()
+
+    def test_mtu_in_virtio_net(self):
+        """
+        Test Case: Test the MTU in virtio-net
+        """
+        MTU_LIST = [9000, 68, 65535]
+        for expected_mtu in MTU_LIST:
+            self.start_vhost_testpmd()
+            self.start_vms(mtu=expected_mtu)
+            self.check_mtu_value_in_vm(mtu=expected_mtu)
+            self.check_mtu_value_in_testpmd(mtu=expected_mtu)
+            self.stop_all_apps()
+
+    def tear_down(self):
+        """
+        run after each test case.
+        """
+        self.dut.kill_all()
+
+    def tear_down_all(self):
+        """
+        Run after each test suite.
+        """
+        pass