diff --git a/spice.proto b/spice.proto
index 1fdead9..29d6a8b 100644
--- a/spice.proto
+++ b/spice.proto
@@ -26,6 +26,15 @@ struct Rect {
     int32 right;
 };
 
+struct Transform {
+    uint32 t00;
+    uint32 t01;
+    uint32 t02;
+    uint32 t10;
+    uint32 t11;
+    uint32 t12;
+};
+
 enum32 link_err {
     OK,
     ERROR,
@@ -52,6 +61,28 @@ flags32 migrate_flags {
     NEED_DATA_TRANSFER
 } @prefix(SPICE_MIGRATE_);
 
+flags32 composite_flags {
+    OP0, OP1, OP2, OP3, OP4, OP5, OP6, OP7,
+    SRC_FILTER0, SRC_FILTER1, SRC_FILTER2,
+    MASK_FILTER0, MASK_FITLER1, MASK_FILTER2,
+
+    SRC_REPEAT0, SRC_REPEAT1,
+    MASK_REPEAT0, MASK_REPEAT1,
+    COMPONENT_ALPHA,
+
+    HAS_MASK,
+    HAS_SRC_TRANSFORM,
+    HAS_MASK_TRANSFORM,
+
+    /* These are used to override the formats given in the images. For
+     * example, if the mask image has format a8r8g8b8, but MASK_OPAQUE
+     * is set, the image should be treated as if it were x8r8g8b8
+     */
+    SOURCE_OPAQUE,
+    MASK_OPAQUE,
+    DEST_OPAQUE,
+} @prefix(SPICE_COMPOSITE_);
+
 enum32 notify_severity {
     INFO,
     WARN,
@@ -321,7 +352,8 @@ enum8 bitmap_fmt {
     16BIT, /* 0555 mode */
     24BIT /* 3 byte, brg */,
     32BIT /* 4 byte, xrgb in little endian format */,
-    RGBA /* 4 byte, argb in little endian format */
+    RGBA /* 4 byte, argb in little endian format */,
+    8BIT_A /* 1 byte, alpha */
 };
 
 flags8 bitmap_flags {
@@ -814,6 +846,28 @@ channel DisplayChannel : BaseChannel {
 	Head heads[count] @end;
     } monitors_config;
 
+    message {
+    	DisplayBase base;
+	struct Composite {
+	    composite_flags flags;
+	    Image *src_bitmap;
+	    switch (flags) {
+	    case HAS_MASK:
+	        Image *mask_bitmap;
+            } a @anon;
+	    switch (flags) {
+	    case HAS_SRC_TRANSFORM:
+	        Transform src_transform;
+            } b @anon;
+	    switch (flags) {
+	    case HAS_MASK_TRANSFORM:
+	        Transform mask_transform;
+            } c @anon;
+	    Point16 src_origin;
+	    Point16 mask_origin;
+	} data;
+    } draw_composite;
+
  client:
     message {
 	uint8 pixmap_cache_id;