[PATCH v6 01/13] vhost-user: add protocol features support

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

The two protocol features messages are introduced by qemu vhost
maintainer(Michael) for extendting vhost-user interface. Here is
an excerpta from the vhost-user spec:

    Any protocol extensions are gated by protocol feature bits,
    which allows full backwards compatibility on both master
    and slave.

The vhost-user multiple queue features will be treated as a vhost-user
extension, hence, we have to implement the two messages first.

VHOST_USER_PROTOCOL_FEATURES is initated to 0, as we don't support
any yet.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---
 lib/librte_vhost/rte_virtio_net.h             |  1 +
 lib/librte_vhost/vhost_user/vhost-net-user.c  | 13 ++++++++++++-
 lib/librte_vhost/vhost_user/vhost-net-user.h  |  2 ++
 lib/librte_vhost/vhost_user/virtio-net-user.c | 13 +++++++++++++
 lib/librte_vhost/vhost_user/virtio-net-user.h |  5 +++++
 lib/librte_vhost/virtio-net.c                 |  5 ++++-
 6 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index a037c15..e3a21e5 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -99,6 +99,7 @@ struct virtio_net {
 	struct vhost_virtqueue	*virtqueue[VIRTIO_QNUM];	/**< Contains all virtqueue information. */
 	struct virtio_memory	*mem;		/**< QEMU memory and memory region information. */
 	uint64_t		features;	/**< Negotiated feature set. */
+	uint64_t		protocol_features;	/**< Negotiated protocol feature set. */
 	uint64_t		device_fh;	/**< device identifier. */
 	uint32_t		flags;		/**< Device flags. Only used to check if device is running on data core. */
 #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c
index d1f8877..bc2ad24 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.c
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
@@ -95,7 +95,9 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_GET_VRING_BASE] = "VHOST_USER_GET_VRING_BASE",
 	[VHOST_USER_SET_VRING_KICK] = "VHOST_USER_SET_VRING_KICK",
 	[VHOST_USER_SET_VRING_CALL] = "VHOST_USER_SET_VRING_CALL",
-	[VHOST_USER_SET_VRING_ERR]  = "VHOST_USER_SET_VRING_ERR"
+	[VHOST_USER_SET_VRING_ERR]  = "VHOST_USER_SET_VRING_ERR",
+	[VHOST_USER_GET_PROTOCOL_FEATURES]  = "VHOST_USER_GET_PROTOCOL_FEATURES",
+	[VHOST_USER_SET_PROTOCOL_FEATURES]  = "VHOST_USER_SET_PROTOCOL_FEATURES",
 };
 
 /**
@@ -363,6 +365,15 @@ vserver_message_handler(int connfd, void *dat, int *remove)
 		ops->set_features(ctx, &features);
 		break;
 
+	case VHOST_USER_GET_PROTOCOL_FEATURES:
+		msg.payload.u64 = VHOST_USER_PROTOCOL_FEATURES;
+		msg.size = sizeof(msg.payload.u64);
+		send_vhost_message(connfd, &msg);
+		break;
+	case VHOST_USER_SET_PROTOCOL_FEATURES:
+		user_set_protocol_features(ctx, msg.payload.u64);
+		break;
+
 	case VHOST_USER_SET_OWNER:
 		ops->set_owner(ctx);
 		break;
diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.h b/lib/librte_vhost/vhost_user/vhost-net-user.h
index 2e72f3c..4490d23 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.h
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.h
@@ -63,6 +63,8 @@ typedef enum VhostUserRequest {
 	VHOST_USER_SET_VRING_KICK = 12,
 	VHOST_USER_SET_VRING_CALL = 13,
 	VHOST_USER_SET_VRING_ERR = 14,
+	VHOST_USER_GET_PROTOCOL_FEATURES = 15,
+	VHOST_USER_SET_PROTOCOL_FEATURES = 16,
 	VHOST_USER_MAX
 } VhostUserRequest;
 
diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index 4689927..360254e 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -316,3 +316,16 @@ user_destroy_device(struct vhost_device_ctx ctx)
 		dev->mem = NULL;
 	}
 }
+
+void
+user_set_protocol_features(struct vhost_device_ctx ctx,
+			   uint64_t protocol_features)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL || protocol_features & ~VHOST_USER_PROTOCOL_FEATURES)
+		return;
+
+	dev->protocol_features = protocol_features;
+}
diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.h b/lib/librte_vhost/vhost_user/virtio-net-user.h
index df24860..e7a6ff4 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.h
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.h
@@ -37,12 +37,17 @@
 #include "vhost-net.h"
 #include "vhost-net-user.h"
 
+#define VHOST_USER_PROTOCOL_FEATURES	0ULL
+
 int user_set_mem_table(struct vhost_device_ctx, struct VhostUserMsg *);
 
 void user_set_vring_call(struct vhost_device_ctx, struct VhostUserMsg *);
 
 void user_set_vring_kick(struct vhost_device_ctx, struct VhostUserMsg *);
 
+void user_set_protocol_features(struct vhost_device_ctx ctx,
+				uint64_t protocol_features);
+
 int user_get_vring_base(struct vhost_device_ctx, struct vhost_vring_state *);
 
 void user_destroy_device(struct vhost_device_ctx);
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index d0f1764..deac6b9 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -67,11 +67,14 @@ struct virtio_net_device_ops const *notify_ops;
 /* root address of the linked list of managed virtio devices */
 static struct virtio_net_config_ll *ll_root;
 
+#define VHOST_USER_F_PROTOCOL_FEATURES	30
+
 /* Features supported by this lib. */
 #define VHOST_SUPPORTED_FEATURES ((1ULL << VIRTIO_NET_F_MRG_RXBUF) | \
 				(1ULL << VIRTIO_NET_F_CTRL_VQ) | \
 				(1ULL << VIRTIO_NET_F_CTRL_RX) | \
-				(1ULL << VHOST_F_LOG_ALL))
+				(1ULL << VHOST_F_LOG_ALL)      | \
+				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES))
 static uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES;
 
 
-- 
1.9.0