diff --git a/lib/librte_vhost/trans_af_unix.c b/lib/librte_vhost/trans_af_unix.c
index 7e119b4..c0ba8df 100644
--- a/lib/librte_vhost/trans_af_unix.c
+++ b/lib/librte_vhost/trans_af_unix.c
@@ -50,7 +50,7 @@ static void vhost_user_read_cb(int connfd, void *dat, int *remove);
  * return bytes# of read on success or negative val on failure. Update fdnum
  * with number of fds read.
  */
-int
+static int
 read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
 		int *fd_num)
 {
@@ -101,8 +101,8 @@ read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
 	return ret;
 }
 
-int
-send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
+static int
+send_fd_message(int sockfd, void *buf, int buflen, int *fds, int fd_num)
 {
 	struct iovec iov;
 	struct msghdr msgh;
@@ -148,6 +148,23 @@ send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
 	return ret;
 }
 
+static int
+af_unix_send_reply(struct virtio_net *dev, struct VhostUserMsg *msg)
+{
+	struct vhost_user_connection *conn =
+		container_of(dev, struct vhost_user_connection, device);
+
+	return send_fd_message(conn->connfd, msg,
+			       VHOST_USER_HDR_SIZE + msg->size, msg->fds, msg->fd_num);
+}
+
+static int
+af_unix_send_slave_req(struct virtio_net *dev, struct VhostUserMsg *msg)
+{
+	return send_fd_message(dev->slave_req_fd, msg,
+			       VHOST_USER_HDR_SIZE + msg->size, msg->fds, msg->fd_num);
+}
+
 static void
 vhost_user_add_connection(int fd, struct vhost_user_socket *vsocket)
 {
@@ -231,6 +248,36 @@ vhost_user_server_new_connection(int fd, void *dat, int *remove __rte_unused)
 	vhost_user_add_connection(fd, vsocket);
 }
 
+/* return bytes# of read on success or negative val on failure. */
+int
+read_vhost_message(int sockfd, struct VhostUserMsg *msg)
+{
+	int ret;
+
+	ret = read_fd_message(sockfd, (char *)msg, VHOST_USER_HDR_SIZE,
+		msg->fds, VHOST_MEMORY_MAX_NREGIONS, &msg->fd_num);
+	if (ret <= 0)
+		return ret;
+
+	if (msg->size) {
+		if (msg->size > sizeof(msg->payload)) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"invalid msg size: %d\n", msg->size);
+			return -1;
+		}
+		ret = read(sockfd, &msg->payload, msg->size);
+		if (ret <= 0)
+			return ret;
+		if (ret != (int)msg->size) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"read control message failed\n");
+			return -1;
+		}
+	}
+
+	return ret;
+}
+
 static void
 vhost_user_read_cb(int connfd, void *dat, int *remove)
 {
@@ -238,10 +285,23 @@ vhost_user_read_cb(int connfd, void *dat, int *remove)
 	struct vhost_user_socket *vsocket = conn->vsocket;
 	struct af_unix_socket *af_vsocket =
 		container_of(vsocket, struct af_unix_socket, socket);
+	struct VhostUserMsg msg;
 	int ret;
 
-	ret = vhost_user_msg_handler(conn->device.vid, connfd);
+	ret = read_vhost_message(connfd, &msg);
+	if (ret <= 0) {
+		if (ret < 0)
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"vhost read message failed\n");
+		else if (ret == 0)
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"vhost peer closed\n");
+		goto err;
+	}
+
+	ret = vhost_user_msg_handler(conn->device.vid, connfd, &msg);
 	if (ret < 0) {
+err:
 		close(connfd);
 		*remove = 1;
 
@@ -638,4 +698,6 @@ const struct vhost_transport_ops af_unix_trans_ops = {
 	.socket_cleanup = af_unix_socket_cleanup,
 	.socket_start = af_unix_socket_start,
 	.vring_call = af_unix_vring_call,
+	.send_reply = af_unix_send_reply,
+	.send_slave_req = af_unix_send_slave_req,
 };
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index b9e4df1..b20773c 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -290,6 +290,7 @@ struct guest_page {
 
 struct virtio_net;
 struct vhost_user_socket;
+struct VhostUserMsg;
 
 /**
  * A structure containing function pointers for transport-specific operations.
@@ -351,6 +352,31 @@ struct vhost_transport_ops {
 	 *  0 on success, -1 on failure
 	 */
 	int (*vring_call)(struct virtio_net *dev, struct vhost_virtqueue *vq);
+
+	/**
+	 * Send a reply to the master.
+	 *
+	 * @param dev
+	 *  vhost device
+	 * @param reply
+	 *  reply message
+	 * @return
+	 *  0 on success, -1 on failure
+	 */
+	int (*send_reply)(struct virtio_net *dev, struct VhostUserMsg *reply);
+
+	/**
+	 * Send a slave request to the master.
+	 *
+	 * @param dev
+	 *  vhost device
+	 * @param req
+	 *  request message
+	 * @return
+	 *  0 on success, -1 on failure
+	 */
+	int (*send_slave_req)(struct virtio_net *dev,
+			      struct VhostUserMsg *req);
 };
 
 /** The traditional AF_UNIX vhost-user protocol transport. */
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index c9e29ec..5c12435 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -80,8 +80,8 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_POSTCOPY_END]  = "VHOST_USER_POSTCOPY_END",
 };
 
-static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
-static int read_vhost_message(int sockfd, struct VhostUserMsg *msg);
+static int send_vhost_reply(struct virtio_net *dev, struct VhostUserMsg *msg);
+int read_vhost_message(int sockfd, struct VhostUserMsg *msg);
 
 static uint64_t
 get_blk_size(int fd)
@@ -1042,7 +1042,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	if (dev->postcopy_listening) {
 		/* Send the addresses back to qemu */
 		msg->fd_num = 0;
-		send_vhost_reply(main_fd, msg);
+		send_vhost_reply(dev, msg);
 
 		/* Wait for qemu to acknolwedge it's got the addresses
 		 * we've got to wait before we're allowed to generate faults.
@@ -1764,49 +1764,8 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
 	[VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
 };
 
-
-/* return bytes# of read on success or negative val on failure. */
 static int
-read_vhost_message(int sockfd, struct VhostUserMsg *msg)
-{
-	int ret;
-
-	ret = read_fd_message(sockfd, (char *)msg, VHOST_USER_HDR_SIZE,
-		msg->fds, VHOST_MEMORY_MAX_NREGIONS, &msg->fd_num);
-	if (ret <= 0)
-		return ret;
-
-	if (msg->size) {
-		if (msg->size > sizeof(msg->payload)) {
-			RTE_LOG(ERR, VHOST_CONFIG,
-				"invalid msg size: %d\n", msg->size);
-			return -1;
-		}
-		ret = read(sockfd, &msg->payload, msg->size);
-		if (ret <= 0)
-			return ret;
-		if (ret != (int)msg->size) {
-			RTE_LOG(ERR, VHOST_CONFIG,
-				"read control message failed\n");
-			return -1;
-		}
-	}
-
-	return ret;
-}
-
-static int
-send_vhost_message(int sockfd, struct VhostUserMsg *msg)
-{
-	if (!msg)
-		return 0;
-
-	return send_fd_message(sockfd, (char *)msg,
-		VHOST_USER_HDR_SIZE + msg->size, msg->fds, msg->fd_num);
-}
-
-static int
-send_vhost_reply(int sockfd, struct VhostUserMsg *msg)
+send_vhost_reply(struct virtio_net *dev, struct VhostUserMsg *msg)
 {
 	if (!msg)
 		return 0;
@@ -1816,7 +1775,7 @@ send_vhost_reply(int sockfd, struct VhostUserMsg *msg)
 	msg->flags |= VHOST_USER_VERSION;
 	msg->flags |= VHOST_USER_REPLY_MASK;
 
-	return send_vhost_message(sockfd, msg);
+	return dev->trans_ops->send_reply(dev, msg);
 }
 
 static int
@@ -1827,7 +1786,7 @@ send_vhost_slave_message(struct virtio_net *dev, struct VhostUserMsg *msg)
 	if (msg->flags & VHOST_USER_NEED_REPLY)
 		rte_spinlock_lock(&dev->slave_req_lock);
 
-	ret = send_vhost_message(dev->slave_req_fd, msg);
+	ret = dev->trans_ops->send_slave_req(dev, msg);
 	if (ret < 0 && (msg->flags & VHOST_USER_NEED_REPLY))
 		rte_spinlock_unlock(&dev->slave_req_lock);
 
@@ -1908,10 +1867,10 @@ vhost_user_unlock_all_queue_pairs(struct virtio_net *dev)
 }
 
 int
-vhost_user_msg_handler(int vid, int fd)
+vhost_user_msg_handler(int vid, int fd, const struct VhostUserMsg *msg_)
 {
+	struct VhostUserMsg msg = *msg_; /* copy so we can build the reply */
 	struct virtio_net *dev;
-	struct VhostUserMsg msg;
 	struct rte_vdpa_device *vdpa_dev;
 	int did = -1;
 	int ret;
@@ -1933,15 +1892,8 @@ vhost_user_msg_handler(int vid, int fd)
 		}
 	}
 
-	ret = read_vhost_message(fd, &msg);
-	if (ret <= 0) {
-		if (ret < 0)
-			RTE_LOG(ERR, VHOST_CONFIG,
-				"vhost read message failed\n");
-		else
-			RTE_LOG(INFO, VHOST_CONFIG,
-				"vhost peer closed\n");
-
+	if (msg.request.master >= VHOST_USER_MAX) {
+		RTE_LOG(ERR, VHOST_CONFIG, "vhost read incorrect message\n");
 		return -1;
 	}
 
@@ -2004,7 +1956,7 @@ vhost_user_msg_handler(int vid, int fd)
 				(void *)&msg);
 		switch (ret) {
 		case RTE_VHOST_MSG_RESULT_REPLY:
-			send_vhost_reply(fd, &msg);
+			send_vhost_reply(dev, &msg);
 			/* Fall-through */
 		case RTE_VHOST_MSG_RESULT_ERR:
 		case RTE_VHOST_MSG_RESULT_OK:
@@ -2038,7 +1990,7 @@ vhost_user_msg_handler(int vid, int fd)
 			RTE_LOG(DEBUG, VHOST_CONFIG,
 				"Processing %s succeeded and needs reply.\n",
 				vhost_message_str[request]);
-			send_vhost_reply(fd, &msg);
+			send_vhost_reply(dev, &msg);
 			handled = true;
 			break;
 		default:
@@ -2053,7 +2005,7 @@ vhost_user_msg_handler(int vid, int fd)
 				(void *)&msg);
 		switch (ret) {
 		case RTE_VHOST_MSG_RESULT_REPLY:
-			send_vhost_reply(fd, &msg);
+			send_vhost_reply(dev, &msg);
 			/* Fall-through */
 		case RTE_VHOST_MSG_RESULT_ERR:
 		case RTE_VHOST_MSG_RESULT_OK:
@@ -2083,7 +2035,7 @@ vhost_user_msg_handler(int vid, int fd)
 		msg.payload.u64 = ret == RTE_VHOST_MSG_RESULT_ERR;
 		msg.size = sizeof(msg.payload.u64);
 		msg.fd_num = 0;
-		send_vhost_reply(fd, &msg);
+		send_vhost_reply(dev, &msg);
 	} else if (ret == RTE_VHOST_MSG_RESULT_ERR) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"vhost message handling failed.\n");
@@ -2161,7 +2113,7 @@ vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm)
 		},
 	};
 
-	ret = send_vhost_message(dev->slave_req_fd, &msg);
+	ret = send_vhost_slave_req(dev, &msg);
 	if (ret < 0) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 				"Failed to send IOTLB miss message (%d)\n",
diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index 2a650fe..0169bd2 100644
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -146,12 +146,7 @@ typedef struct VhostUserMsg {
 
 
 /* vhost_user.c */
-int vhost_user_msg_handler(int vid, int fd);
+int vhost_user_msg_handler(int vid, int fd, const struct VhostUserMsg *msg);
 int vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm);
 
-/* socket.c */
-int read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
-		int *fd_num);
-int send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num);
-
 #endif
