tests/vm: Use -cpu max rather than -cpu host

-cpu max works with any accelerator, so we don't need
to use it only conditionally if not using KVM. Just use
it all the time.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180820155554.23476-1-peter.maydell@linaro.org>
Signed-off-by: Fam Zheng <famz@redhat.com>

tests/vm/basevm.py

@@ -65,6 +65,7 @@ class BaseVM(object):
             self._stdout = self._devnull
         self._args = [ \
             "-nodefaults", "-m", "4G",
+            "-cpu", "max",
             "-netdev", "user,id=vnet,hostfwd=:127.0.0.1:0-:22",
             "-device", "virtio-net-pci,netdev=vnet",
             "-vnc", "127.0.0.1:0,to=20",
@@ -72,11 +73,9 @@ class BaseVM(object):
         if vcpus:
             self._args += ["-smp", str(vcpus)]
         if os.access("/dev/kvm", os.R_OK | os.W_OK):
-            self._args += ["-cpu", "host"]
             self._args += ["-enable-kvm"]
         else:
             logging.info("KVM not available, not using -enable-kvm")
-            self._args += ["-cpu", "max"]
         self._data_args = []
 
     def _download_with_cache(self, url, sha256sum=None):