[QEMU,2/3] tests/migration: Introduce dirty-ring-size option into guestperf

diff --git a/tests/migration/guestperf/engine.py b/tests/migration/guestperf/engine.py
index e69d16a62c..29ebb5011b 100644
--- a/tests/migration/guestperf/engine.py
+++ b/tests/migration/guestperf/engine.py
@@ -325,7 +325,6 @@  class Engine(object):
             cmdline = "'" + cmdline + "'"
 
         argv = [
-            "-accel", "kvm",
             "-cpu", "host",
             "-kernel", self._kernel,
             "-initrd", self._initrd,
@@ -333,6 +332,11 @@  class Engine(object):
             "-m", str((hardware._mem * 1024) + 512),
             "-smp", str(hardware._cpus),
         ]
+        if hardware._dirty_ring_size:
+            argv.extend(["-accel", "kvm,dirty-ring-size=%s" %
+                         hardware._dirty_ring_size])
+        else:
+            argv.extend(["-accel", "kvm"])
 
         argv.extend(self._get_qemu_serial_args())
 
diff --git a/tests/migration/guestperf/hardware.py b/tests/migration/guestperf/hardware.py
index 3145785ffd..f779cc050b 100644
--- a/tests/migration/guestperf/hardware.py
+++ b/tests/migration/guestperf/hardware.py
@@ -23,7 +23,8 @@  class Hardware(object):
                  src_cpu_bind=None, src_mem_bind=None,
                  dst_cpu_bind=None, dst_mem_bind=None,
                  prealloc_pages = False,
-                 huge_pages=False, locked_pages=False):
+                 huge_pages=False, locked_pages=False,
+                 dirty_ring_size=0):
         self._cpus = cpus
         self._mem = mem # GiB
         self._src_mem_bind = src_mem_bind # List of NUMA nodes
@@ -33,6 +34,7 @@  class Hardware(object):
         self._prealloc_pages = prealloc_pages
         self._huge_pages = huge_pages
         self._locked_pages = locked_pages
+        self._dirty_ring_size = dirty_ring_size
 
 
     def serialize(self):
@@ -46,6 +48,7 @@  class Hardware(object):
             "prealloc_pages": self._prealloc_pages,
             "huge_pages": self._huge_pages,
             "locked_pages": self._locked_pages,
+            "dirty_ring_size": self._dirty_ring_size,
         }
 
     @classmethod
@@ -59,4 +62,5 @@  class Hardware(object):
             data["dst_mem_bind"],
             data["prealloc_pages"],
             data["huge_pages"],
-            data["locked_pages"])
+            data["locked_pages"],
+            data["dirty_ring_size"])
diff --git a/tests/migration/guestperf/shell.py b/tests/migration/guestperf/shell.py
index 8a809e3dda..7d6b8cd7cf 100644
--- a/tests/migration/guestperf/shell.py
+++ b/tests/migration/guestperf/shell.py
@@ -60,6 +60,8 @@  class BaseShell(object):
         parser.add_argument("--prealloc-pages", dest="prealloc_pages", default=False)
         parser.add_argument("--huge-pages", dest="huge_pages", default=False)
         parser.add_argument("--locked-pages", dest="locked_pages", default=False)
+        parser.add_argument("--dirty-ring-size", dest="dirty_ring_size",
+                            default=0, type=int)
 
         self._parser = parser
 
@@ -89,7 +91,9 @@  class BaseShell(object):
 
                         locked_pages=args.locked_pages,
                         huge_pages=args.huge_pages,
-                        prealloc_pages=args.prealloc_pages)
+                        prealloc_pages=args.prealloc_pages,
+
+                        dirty_ring_size=args.dirty_ring_size)
 
 
 class Shell(BaseShell):