From: Hyman Huang <yong.huang@smartx.com>

The way to enable multifd migration has been changed by commit,
82137e6c8c (migration: enforce multifd and postcopy preempt to
be set before incoming), and guestperf has not made the
necessary changes. If multifd migration had been enabled in the
previous manner, the following error would have occurred:
Multifd must be set before incoming starts

Supporting deferred migration will fix it.

Signed-off-by: Hyman Huang <yong.huang@smartx.com>
---
 scripts/migration/guestperf/engine.py | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/scripts/migration/guestperf/engine.py b/scripts/migration/guestperf/engine.py
index 608d7270f6..4cddd05a9d 100644
--- a/scripts/migration/guestperf/engine.py
+++ b/scripts/migration/guestperf/engine.py
@@ -106,7 +106,8 @@ def _migrate_progress(self, vm):
             info.get("dirty-limit-ring-full-time", 0),
         )
 
-    def _migrate(self, hardware, scenario, src, dst, connect_uri):
+    def _migrate(self, hardware, scenario, src,
+                 dst, connect_uri, defer_migrate):
         src_qemu_time = []
         src_vcpu_time = []
         src_pid = src.get_pid()
@@ -220,6 +221,8 @@ def _migrate(self, hardware, scenario, src, dst, connect_uri):
             resp = src.cmd("migrate-set-parameters",
                            vcpu_dirty_limit=scenario._vcpu_dirty_limit)
 
+        if defer_migrate:
+            resp = dst.cmd("migrate-incoming", uri=connect_uri)
         resp = src.cmd("migrate", uri=connect_uri)
 
         post_copy = False
@@ -373,11 +376,14 @@ def _get_common_args(self, hardware, tunnelled=False):
     def _get_src_args(self, hardware):
         return self._get_common_args(hardware)
 
-    def _get_dst_args(self, hardware, uri):
+    def _get_dst_args(self, hardware, uri, defer_migrate):
         tunnelled = False
         if self._dst_host != "localhost":
             tunnelled = True
         argv = self._get_common_args(hardware, tunnelled)
+
+        if defer_migrate:
+            return argv + ["-incoming", "defer"]
         return argv + ["-incoming", uri]
 
     @staticmethod
@@ -439,6 +445,9 @@ def run(self, hardware, scenario, result_dir=os.getcwd()):
             except:
                 pass
 
+        if scenario._multifd:
+            defer_migrate = True
+
         if self._dst_host != "localhost":
             dstmonaddr = ("localhost", 9001)
         else:
@@ -452,7 +461,7 @@ def run(self, hardware, scenario, result_dir=os.getcwd()):
                           monitor_address=srcmonaddr)
 
         dst = QEMUMachine(self._binary,
-                          args=self._get_dst_args(hardware, uri),
+                          args=self._get_dst_args(hardware, uri, defer_migrate),
                           wrapper=self._get_dst_wrapper(hardware),
                           name="qemu-dst-%d" % os.getpid(),
                           monitor_address=dstmonaddr)
@@ -461,7 +470,8 @@ def run(self, hardware, scenario, result_dir=os.getcwd()):
             src.launch()
             dst.launch()
 
-            ret = self._migrate(hardware, scenario, src, dst, uri)
+            ret = self._migrate(hardware, scenario, src,
+                                dst, uri, defer_migrate)
             progress_history = ret[0]
             qemu_timings = ret[1]
             vcpu_timings = ret[2]
-- 
2.11.0