[dpdk-dev] [RFC 03/19] vhost: prepare send_vhost_message() to slave requests

[Maxime Coquelin <maxime.coquelin@redhat.com>]

send_vhost_message() is currently only used to send
replies, so it modifies message flags to perpare the
reply.

With upcoming channel for backend initiated request,
this function can be used to send requests.

This patch introduces a new send_vhost_reply() that
does the message flags modifications, and makes
send_vhost_message() generic.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 5b3b881..8984dcb 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -877,8 +877,16 @@ read_vhost_message(int sockfd, struct VhostUserMsg *msg)
 static int
 send_vhost_message(int sockfd, struct VhostUserMsg *msg)
 {
-	int ret;
+	if (!msg)
+		return 0;
+
+	return send_fd_message(sockfd, (char *)msg,
+		VHOST_USER_HDR_SIZE + msg->size, NULL, 0);
+}
 
+static int
+send_vhost_reply(int sockfd, struct VhostUserMsg *msg)
+{
 	if (!msg)
 		return 0;
 
@@ -887,10 +895,7 @@ send_vhost_message(int sockfd, struct VhostUserMsg *msg)
 	msg->flags |= VHOST_USER_VERSION;
 	msg->flags |= VHOST_USER_REPLY_MASK;
 
-	ret = send_fd_message(sockfd, (char *)msg,
-		VHOST_USER_HDR_SIZE + msg->size, NULL, 0);
-
-	return ret;
+	return send_vhost_message(sockfd, msg);
 }
 
 /*
@@ -984,7 +989,7 @@ vhost_user_msg_handler(int vid, int fd)
 	case VHOST_USER_GET_FEATURES:
 		msg.payload.u64 = vhost_user_get_features(dev);
 		msg.size = sizeof(msg.payload.u64);
-		send_vhost_message(fd, &msg);
+		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_FEATURES:
 		vhost_user_set_features(dev, msg.payload.u64);
@@ -993,7 +998,7 @@ vhost_user_msg_handler(int vid, int fd)
 	case VHOST_USER_GET_PROTOCOL_FEATURES:
 		msg.payload.u64 = VHOST_USER_PROTOCOL_FEATURES;
 		msg.size = sizeof(msg.payload.u64);
-		send_vhost_message(fd, &msg);
+		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_PROTOCOL_FEATURES:
 		vhost_user_set_protocol_features(dev, msg.payload.u64);
@@ -1015,7 +1020,7 @@ vhost_user_msg_handler(int vid, int fd)
 
 		/* it needs a reply */
 		msg.size = sizeof(msg.payload.u64);
-		send_vhost_message(fd, &msg);
+		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_LOG_FD:
 		close(msg.fds[0]);
@@ -1035,7 +1040,7 @@ vhost_user_msg_handler(int vid, int fd)
 	case VHOST_USER_GET_VRING_BASE:
 		vhost_user_get_vring_base(dev, &msg);
 		msg.size = sizeof(msg.payload.state);
-		send_vhost_message(fd, &msg);
+		send_vhost_reply(fd, &msg);
 		break;
 
 	case VHOST_USER_SET_VRING_KICK:
@@ -1054,7 +1059,7 @@ vhost_user_msg_handler(int vid, int fd)
 	case VHOST_USER_GET_QUEUE_NUM:
 		msg.payload.u64 = VHOST_MAX_QUEUE_PAIRS;
 		msg.size = sizeof(msg.payload.u64);
-		send_vhost_message(fd, &msg);
+		send_vhost_reply(fd, &msg);
 		break;
 
 	case VHOST_USER_SET_VRING_ENABLE:
@@ -1077,7 +1082,7 @@ vhost_user_msg_handler(int vid, int fd)
 	if (msg.flags & VHOST_USER_NEED_REPLY) {
 		msg.payload.u64 = !!ret;
 		msg.size = sizeof(msg.payload.u64);
-		send_vhost_message(fd, &msg);
+		send_vhost_reply(fd, &msg);
 	}
 
 	if (!(dev->flags & VIRTIO_DEV_RUNNING) && virtio_is_ready(dev)) {
-- 
2.9.4