spice: stop server for qxl hard reset

Hard reset can happen at any time.  We should be able to put qxl into a
known-good state no matter what.  Stop spice server thread for reset so
it can't be confused by fetching stale commands lingering around in the
rings while we reset is ongoing.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/display/qxl.c

@@ -1144,8 +1144,14 @@ static void qxl_soft_reset(PCIQXLDevice *d)
 
 static void qxl_hard_reset(PCIQXLDevice *d, int loadvm)
 {
+    bool startstop = qemu_spice_display_is_running(&d->ssd);
+
     trace_qxl_hard_reset(d->id, loadvm);
 
+    if (startstop) {
+        qemu_spice_display_stop();
+    }
+
     qxl_spice_reset_cursor(d);
     qxl_spice_reset_image_cache(d);
     qxl_reset_surfaces(d);
@@ -1159,6 +1165,10 @@ static void qxl_hard_reset(PCIQXLDevice *d, int loadvm)
     }
     qemu_spice_create_host_memslot(&d->ssd);
     qxl_soft_reset(d);
+
+    if (startstop) {
+        qemu_spice_display_start();
+    }
 }
 
 static void qxl_reset_handler(DeviceState *dev)