diff --git a/gns3server/compute/qemu/qemu_vm.py b/gns3server/compute/qemu/qemu_vm.py
index 0b49b9e0..63df5ef5 100644
--- a/gns3server/compute/qemu/qemu_vm.py
+++ b/gns3server/compute/qemu/qemu_vm.py
@@ -1489,6 +1489,11 @@ class QemuVM(BaseNode):
         command.extend(["-smp", "cpus={}".format(self._cpus)])
         if self._run_with_kvm(self.qemu_path, self._options):
             command.extend(["-enable-kvm"])
+            version = yield from self.manager.get_qemu_version(self.qemu_path)
+            # Issue on some combo Intel CPU + KVM + Qemu 2.4.0
+            # https://github.com/GNS3/gns3-server/issues/685
+            if version and parse_version(version) >= parse_version("2.4.0"):
+                command.extend(["-machine smm=off"])
         command.extend(["-boot", "order={}".format(self._boot_priority)])
         cdrom_option = self._cdrom_option()
         command.extend(cdrom_option)
diff --git a/gns3server/compute/virtualbox/virtualbox_vm.py b/gns3server/compute/virtualbox/virtualbox_vm.py
index 7f172362..06723fd9 100644
--- a/gns3server/compute/virtualbox/virtualbox_vm.py
+++ b/gns3server/compute/virtualbox/virtualbox_vm.py
@@ -265,7 +265,7 @@ class VirtualBoxVM(BaseNode):
                 log.debug("Stop result: {}".format(result))
 
             log.info("VirtualBox VM '{name}' [{id}] stopped".format(name=self.name, id=self.id))
-            # yield from asyncio.sleep(0.5)  # give some time for VirtualBox to unlock the VM
+            yield from asyncio.sleep(0.5)  # give some time for VirtualBox to unlock the VM
             try:
                 # deactivate the first serial port
                 yield from self._modify_vm("--uart1 off")
diff --git a/tests/compute/qemu/test_qemu_vm.py b/tests/compute/qemu/test_qemu_vm.py
index 972ec1eb..60841a6c 100644
--- a/tests/compute/qemu/test_qemu_vm.py
+++ b/tests/compute/qemu/test_qemu_vm.py
@@ -22,7 +22,7 @@ import os
 import sys
 import stat
 import re
-from tests.utils import asyncio_patch
+from tests.utils import asyncio_patch, AsyncioMagicMock
 
 
 from unittest import mock
@@ -436,6 +436,65 @@ def test_build_command(vm, loop, fake_qemu_binary, port_manager):
         ]
 
 
+def test_build_command_kvm(linux_platform, vm, loop, fake_qemu_binary, port_manager):
+    """
+    Qemu 2.4 introduce an issue with KVM
+    """
+    vm._run_with_kvm = MagicMock(return_value=True)
+    vm.manager.get_qemu_version = AsyncioMagicMock(return_value="2.3.2")
+    os.environ["DISPLAY"] = "0:0"
+    with asyncio_patch("asyncio.create_subprocess_exec", return_value=MagicMock()) as process:
+        cmd = loop.run_until_complete(asyncio.async(vm._build_command()))
+        assert cmd == [
+            fake_qemu_binary,
+            "-name",
+            "test",
+            "-m",
+            "256M",
+            "-smp",
+            "cpus=1",
+            "-enable-kvm",
+            "-boot",
+            "order=c",
+            "-serial",
+            "telnet:127.0.0.1:{},server,nowait".format(vm.console),
+            "-net",
+            "none",
+            "-device",
+            "e1000,mac={}".format(vm._mac_address)
+        ]
+
+
+def test_build_command_kvm_2_4(linux_platform, vm, loop, fake_qemu_binary, port_manager):
+    """
+    Qemu 2.4 introduce an issue with KVM
+    """
+    vm._run_with_kvm = MagicMock(return_value=True)
+    vm.manager.get_qemu_version = AsyncioMagicMock(return_value="2.4.2")
+    os.environ["DISPLAY"] = "0:0"
+    with asyncio_patch("asyncio.create_subprocess_exec", return_value=MagicMock()) as process:
+        cmd = loop.run_until_complete(asyncio.async(vm._build_command()))
+        assert cmd == [
+            fake_qemu_binary,
+            "-name",
+            "test",
+            "-m",
+            "256M",
+            "-smp",
+            "cpus=1",
+            "-enable-kvm",
+            "-machine smm=off",
+            "-boot",
+            "order=c",
+            "-serial",
+            "telnet:127.0.0.1:{},server,nowait".format(vm.console),
+            "-net",
+            "none",
+            "-device",
+            "e1000,mac={}".format(vm._mac_address)
+        ]
+
+
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Not supported on Windows")
 def test_build_command_without_display(vm, loop, fake_qemu_binary):