@@ -201,7 +201,7 @@ The packet transmission flow is:
 Virtio PMD Rx/Tx Callbacks
 --------------------------
 
-Virtio driver has 3 Rx callbacks and 2 Tx callbacks.
+Virtio driver has 4 Rx callbacks and 3 Tx callbacks.
 
 Rx callbacks:
 

@@ -215,6 +215,9 @@ Rx callbacks:
    Vector version without mergeable Rx buffer support, also fixes the available
    ring indexes and uses vector instructions to optimize performance.
 
+#. ``virtio_recv_mergeable_pkts_inorder``:
+   In-order version with mergeable Rx buffer support.
+
 Tx callbacks:
 
 #. ``virtio_xmit_pkts``:

@@ -223,13 +226,17 @@ Tx callbacks:
 #. ``virtio_xmit_pkts_simple``:
    Vector version fixes the available ring indexes to optimize performance.
 
+#. ``virtio_xmit_pkts_inorder``:
+   In-order version.
 
-By default, the non-vector callbacks are used:
+By default, the in-order callbacks are used:
 
 *   For Rx: If mergeable Rx buffers is disabled then ``virtio_recv_pkts`` is
-    used; otherwise ``virtio_recv_mergeable_pkts``.
+    used; If in-order is enabled then ``virtio_recv_mergeable_pkts_inirder``;
+    otherwise ``virtio_recv_mergeable_pkts``.
 
-*   For Tx: ``virtio_xmit_pkts``.
+*   For Tx: If in-order is enabled then ``virtio_xmit_pkts_inorder``;
+    otherwise ``virtio_xmit_pkts``.
 
 
 Vector callbacks will be used when:

@@ -242,6 +249,8 @@ Vector callbacks will be used when:
 
 *   Mergeable Rx buffers is disabled.
 
+*   In-order is enabled
+
 The corresponding callbacks are:
 
 *   For Rx: ``virtio_recv_pkts_vec``.