diff --git a/core/res/res/drawable/emulator_circular_window_overlay.xml b/core/res/res/drawable/emulator_circular_window_overlay.xml
new file mode 100644
index 0000000..7616b37
--- /dev/null
+++ b/core/res/res/drawable/emulator_circular_window_overlay.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<!-- Default to an empty shape drawable -->
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+       android:shape="rectangle">
+</shape>
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index f3b3077..1b12ff2 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -1611,6 +1611,10 @@
     <!-- default window ShowCircularMask property -->
     <bool name="config_windowShowCircularMask">false</bool>
 
+    <!-- default value for whether circular emulators (ro.emulator.circular)
+         should show a display overlay on the screen -->
+    <bool name="config_windowEnableCircularEmulatorDisplayOverlay">false</bool>
+
     <!-- Defines the default set of global actions. Actions may still be disabled or hidden based
          on the current state of the device.
          Each item must be one of the following strings:
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index ecfbefe..f5197ec 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -293,6 +293,7 @@
   <java-symbol type="bool" name="config_windowIsRound" />
   <java-symbol type="bool" name="config_hasRecents" />
   <java-symbol type="bool" name="config_windowShowCircularMask" />
+  <java-symbol type="bool" name="config_windowEnableCircularEmulatorDisplayOverlay" />
 
   <java-symbol type="integer" name="config_bluetooth_max_advertisers" />
   <java-symbol type="integer" name="config_bluetooth_max_scan_filters" />
@@ -1155,6 +1156,7 @@
   <java-symbol type="drawable" name="ic_corp_badge" />
   <java-symbol type="drawable" name="ic_corp_icon_badge" />
   <java-symbol type="drawable" name="ic_corp_icon" />
+  <java-symbol type="drawable" name="emulator_circular_window_overlay" />
 
   <java-symbol type="drawable" name="sim_light_blue" />
   <java-symbol type="drawable" name="sim_light_green" />
diff --git a/services/core/java/com/android/server/wm/CircularDisplayMask.java b/services/core/java/com/android/server/wm/CircularDisplayMask.java
index 64b852b..a7d41fa 100644
--- a/services/core/java/com/android/server/wm/CircularDisplayMask.java
+++ b/services/core/java/com/android/server/wm/CircularDisplayMask.java
@@ -63,8 +63,14 @@
 
         SurfaceControl ctrl = null;
         try {
-            ctrl = new SurfaceControl(session, "CircularDisplayMask",
-                mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
+            if (WindowManagerService.DEBUG_SURFACE_TRACE) {
+                ctrl = new WindowStateAnimator.SurfaceTrace(session, "CircularDisplayMask",
+                        mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT,
+                        SurfaceControl.HIDDEN);
+            } else {
+                ctrl = new SurfaceControl(session, "CircularDisplayMask", mScreenSize.x,
+                        mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
+            }
             ctrl.setLayerStack(display.getLayerStack());
             ctrl.setLayer(zOrder);
             ctrl.setPosition(0, 0);
diff --git a/services/core/java/com/android/server/wm/EmulatorDisplayOverlay.java b/services/core/java/com/android/server/wm/EmulatorDisplayOverlay.java
new file mode 100644
index 0000000..62f2b48
--- /dev/null
+++ b/services/core/java/com/android/server/wm/EmulatorDisplayOverlay.java
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.wm;
+
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.PixelFormat;
+import android.graphics.Point;
+import android.graphics.PorterDuff;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.util.Slog;
+import android.view.Display;
+import android.view.Surface;
+import android.view.Surface.OutOfResourcesException;
+import android.view.SurfaceControl;
+import android.view.SurfaceSession;
+
+class EmulatorDisplayOverlay {
+    private static final String TAG = "EmulatorDisplayOverlay";
+
+    // Display dimensions
+    private Point mScreenSize;
+
+    private final SurfaceControl mSurfaceControl;
+    private final Surface mSurface = new Surface();
+    private int mLastDW;
+    private int mLastDH;
+    private boolean mDrawNeeded;
+    private Drawable mOverlay;
+    private int mRotation;
+    private boolean mVisible;
+
+    public EmulatorDisplayOverlay(Context context, Display display, SurfaceSession session,
+            int zOrder) {
+        mScreenSize = new Point();
+        display.getSize(mScreenSize);
+
+        SurfaceControl ctrl = null;
+        try {
+            if (WindowManagerService.DEBUG_SURFACE_TRACE) {
+                ctrl = new WindowStateAnimator.SurfaceTrace(session, "EmulatorDisplayOverlay",
+                        mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT,
+                        SurfaceControl.HIDDEN);
+            } else {
+                ctrl = new SurfaceControl(session, "EmulatorDisplayOverlay", mScreenSize.x,
+                        mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
+            }
+            ctrl.setLayerStack(display.getLayerStack());
+            ctrl.setLayer(zOrder);
+            ctrl.setPosition(0, 0);
+            ctrl.show();
+            mSurface.copyFrom(ctrl);
+        } catch (OutOfResourcesException e) {
+        }
+        mSurfaceControl = ctrl;
+        mDrawNeeded = true;
+        mOverlay = context.getDrawable(
+                com.android.internal.R.drawable.emulator_circular_window_overlay);
+    }
+
+    private void drawIfNeeded() {
+        if (!mDrawNeeded || !mVisible) {
+            return;
+        }
+        mDrawNeeded = false;
+
+        Rect dirty = new Rect(0, 0, mScreenSize.x, mScreenSize.y);
+        Canvas c = null;
+        try {
+            c = mSurface.lockCanvas(dirty);
+        } catch (IllegalArgumentException e) {
+        } catch (OutOfResourcesException e) {
+        }
+        if (c == null) {
+            return;
+        }
+        c.drawColor(Color.TRANSPARENT, PorterDuff.Mode.SRC);
+        mSurfaceControl.setPosition(0, 0);
+        mOverlay.setBounds(0, 0, mScreenSize.x, mScreenSize.y);
+        mOverlay.draw(c);
+        mSurface.unlockCanvasAndPost(c);
+    }
+
+    // Note: caller responsible for being inside
+    // Surface.openTransaction() / closeTransaction()
+    public void setVisibility(boolean on) {
+        if (mSurfaceControl == null) {
+            return;
+        }
+        mVisible = on;
+        drawIfNeeded();
+        if (on) {
+            mSurfaceControl.show();
+        } else {
+            mSurfaceControl.hide();
+        }
+    }
+
+    void positionSurface(int dw, int dh, int rotation) {
+        if (mLastDW == dw && mLastDH == dh && mRotation == rotation) {
+            return;
+        }
+        mLastDW = dw;
+        mLastDH = dh;
+        mDrawNeeded = true;
+        mRotation = rotation;
+        drawIfNeeded();
+    }
+
+}
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 8e45081..434e48f 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -20,6 +20,7 @@
 
 import static android.view.WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
 import android.app.AppOpsManager;
+import android.os.Build;
 import android.util.ArraySet;
 import android.util.TimeUtils;
 import android.view.IWindowId;
@@ -295,6 +296,8 @@
     private static final int SYSTEM_UI_FLAGS_LAYOUT_STABLE_FULLSCREEN =
             View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
 
+    private static final String PROPERTY_EMULATOR_CIRCULAR = "ro.emulator.circular";
+
     final private KeyguardDisableHandler mKeyguardDisableHandler;
 
     final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@@ -441,6 +444,7 @@
     Watermark mWatermark;
     StrictModeFlash mStrictModeFlash;
     CircularDisplayMask mCircularDisplayMask;
+    EmulatorDisplayOverlay mEmulatorDisplayOverlay;
     FocusedStackFrame mFocusedStackFrame;
 
     int mFocusedStackLayer;
@@ -881,6 +885,7 @@
         }
 
         showCircularDisplayMaskIfNeeded();
+        showEmulatorDisplayOverlayIfNeeded();
     }
 
     public InputMonitor getInputMonitor() {
@@ -5767,7 +5772,16 @@
                 com.android.internal.R.bool.config_windowIsRound)
                 && mContext.getResources().getBoolean(
                 com.android.internal.R.bool.config_windowShowCircularMask)) {
-            mH.sendMessage(mH.obtainMessage(H.SHOW_DISPLAY_MASK));
+            mH.sendMessage(mH.obtainMessage(H.SHOW_CIRCULAR_DISPLAY_MASK));
+        }
+    }
+
+    public void showEmulatorDisplayOverlayIfNeeded() {
+        if (mContext.getResources().getBoolean(
+                com.android.internal.R.bool.config_windowEnableCircularEmulatorDisplayOverlay)
+                && SystemProperties.getBoolean(PROPERTY_EMULATOR_CIRCULAR, false)
+                && Build.HARDWARE.contains("goldfish")) {
+            mH.sendMessage(mH.obtainMessage(H.SHOW_EMULATOR_DISPLAY_OVERLAY));
         }
     }
 
@@ -5775,12 +5789,12 @@
         synchronized(mWindowMap) {
 
             if (SHOW_LIGHT_TRANSACTIONS) Slog.i(TAG,
-                    ">>> OPEN TRANSACTION showDisplayMask");
+                    ">>> OPEN TRANSACTION showCircularMask");
             SurfaceControl.openTransaction();
             try {
                 // TODO(multi-display): support multiple displays
                 if (mCircularDisplayMask == null) {
-                    int screenOffset = (int) mContext.getResources().getDimensionPixelSize(
+                    int screenOffset = mContext.getResources().getDimensionPixelSize(
                             com.android.internal.R.dimen.circular_display_mask_offset);
 
                     mCircularDisplayMask = new CircularDisplayMask(
@@ -5794,7 +5808,32 @@
             } finally {
                 SurfaceControl.closeTransaction();
                 if (SHOW_LIGHT_TRANSACTIONS) Slog.i(TAG,
-                        "<<< CLOSE TRANSACTION showDisplayMask");
+                        "<<< CLOSE TRANSACTION showCircularMask");
+            }
+        }
+    }
+
+    public void showEmulatorDisplayOverlay() {
+        synchronized(mWindowMap) {
+
+            if (SHOW_LIGHT_TRANSACTIONS) Slog.i(TAG,
+                    ">>> OPEN TRANSACTION showEmulatorDisplayOverlay");
+            SurfaceControl.openTransaction();
+            try {
+                if (mEmulatorDisplayOverlay == null) {
+                    mEmulatorDisplayOverlay = new EmulatorDisplayOverlay(
+                            mContext,
+                            getDefaultDisplayContentLocked().getDisplay(),
+                            mFxSession,
+                            mPolicy.windowTypeToLayerLw(
+                                    WindowManager.LayoutParams.TYPE_POINTER)
+                                    * TYPE_LAYER_MULTIPLIER + 10);
+                }
+                mEmulatorDisplayOverlay.setVisibility(true);
+            } finally {
+                SurfaceControl.closeTransaction();
+                if (SHOW_LIGHT_TRANSACTIONS) Slog.i(TAG,
+                        "<<< CLOSE TRANSACTION showEmulatorDisplayOverlay");
             }
         }
     }
@@ -7425,7 +7464,8 @@
 
         public static final int NEW_ANIMATOR_SCALE = 34;
 
-        public static final int SHOW_DISPLAY_MASK = 35;
+        public static final int SHOW_CIRCULAR_DISPLAY_MASK = 35;
+        public static final int SHOW_EMULATOR_DISPLAY_OVERLAY = 36;
 
         @Override
         public void handleMessage(Message msg) {
@@ -7821,11 +7861,16 @@
                     break;
                 }
 
-                case SHOW_DISPLAY_MASK: {
+                case SHOW_CIRCULAR_DISPLAY_MASK: {
                     showCircularMask();
                     break;
                 }
 
+                case SHOW_EMULATOR_DISPLAY_OVERLAY: {
+                    showEmulatorDisplayOverlay();
+                    break;
+                }
+
                 case DO_ANIMATION_CALLBACK: {
                     try {
                         ((IRemoteCallback)msg.obj).sendResult(null);
@@ -9395,6 +9440,9 @@
             if (mCircularDisplayMask != null) {
                 mCircularDisplayMask.positionSurface(defaultDw, defaultDh, mRotation);
             }
+            if (mEmulatorDisplayOverlay != null) {
+                mEmulatorDisplayOverlay.positionSurface(defaultDw, defaultDh, mRotation);
+            }
 
             boolean focusDisplayed = false;