ena: Amazon Elastic Network Adapter (ENA) native driver

Type: feature
Change-Id: Icd9de05f2cbac0e5a6dfb1f1414f21dc4b893104
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vlib/buffer.h b/src/vlib/buffer.h
index 4de2dea..a747ea9 100644
--- a/src/vlib/buffer.h
+++ b/src/vlib/buffer.h
@@ -236,6 +236,7 @@
 	       "VLIB_BUFFER_PRE_DATA_SIZE must be divisible by cache line size");
 
 #define VLIB_BUFFER_HDR_SIZE  (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
+#define VLIB_BUFFER_INVALID_INDEX 0xffffffff
 
 /** \brief Prefetch buffer metadata.
     The first 64 bytes of buffer contains most header information