[dpdk-dev] [PATCH v3 1/2] net/virtio: add vhost-user protocol features support

[Adrian Moreno <amorenoz@redhat.com>]

From: Maxime Coquelin <maxime.coquelin@redhat.com>

This patch adds support for Vhost-user protocol features.
It is required to support protocol features that were not in
initial Vhost-user specification, such as reply-ack, MTU...

Also, this patch prevents Virtio multiqueue feature negotiation
if the slave does not support MQ protocol feature as stated
in Vhost-user specification:
"The multiple queues feature is supported only when the protocol
feature ``VHOST_USER_PROTOCOL_F_MQ`` (bit 0) is set."

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/net/virtio/virtio_user/vhost.h        |  9 +++++
 drivers/net/virtio/virtio_user/vhost_user.c   |  5 +++
 .../net/virtio/virtio_user/virtio_user_dev.c  | 39 ++++++++++++++++++-
 .../net/virtio/virtio_user/virtio_user_dev.h  |  3 ++
 drivers/net/virtio/virtio_user_ethdev.c       | 19 +++++++++
 5 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/vhost.h b/drivers/net/virtio/virtio_user/vhost.h
index 1e784e58e..9ace1a90c 100644
--- a/drivers/net/virtio/virtio_user/vhost.h
+++ b/drivers/net/virtio/virtio_user/vhost.h
@@ -44,6 +44,15 @@ struct vhost_vring_addr {
 	uint64_t log_guest_addr;
 };
 
+#ifndef VHOST_USER_F_PROTOCOL_FEATURES
+#define VHOST_USER_F_PROTOCOL_FEATURES 30
+#endif
+
+/** Protocol features. */
+#ifndef VHOST_USER_PROTOCOL_F_MQ
+#define VHOST_USER_PROTOCOL_F_MQ	0
+#endif
+
 enum vhost_user_request {
 	VHOST_USER_NONE = 0,
 	VHOST_USER_GET_FEATURES = 1,
diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c
index 74b82e56e..c35c11fe5 100644
--- a/drivers/net/virtio/virtio_user/vhost_user.c
+++ b/drivers/net/virtio/virtio_user/vhost_user.c
@@ -241,6 +241,8 @@ const char * const vhost_msg_strings[] = {
 	[VHOST_USER_SET_VRING_KICK] = "VHOST_SET_VRING_KICK",
 	[VHOST_USER_SET_MEM_TABLE] = "VHOST_SET_MEM_TABLE",
 	[VHOST_USER_SET_VRING_ENABLE] = "VHOST_SET_VRING_ENABLE",
+	[VHOST_USER_GET_PROTOCOL_FEATURES ] = "VHOST_USER_GET_PROTOCOL_FEATURES",
+	[VHOST_USER_SET_PROTOCOL_FEATURES ] = "VHOST_USER_SET_PROTOCOL_FEATURES",
 };
 
 static int
@@ -269,10 +271,12 @@ vhost_user_sock(struct virtio_user_dev *dev,
 
 	switch (req) {
 	case VHOST_USER_GET_FEATURES:
+	case VHOST_USER_GET_PROTOCOL_FEATURES:
 		need_reply = 1;
 		break;
 
 	case VHOST_USER_SET_FEATURES:
+	case VHOST_USER_SET_PROTOCOL_FEATURES:
 	case VHOST_USER_SET_LOG_BASE:
 		msg.payload.u64 = *((__u64 *)arg);
 		msg.size = sizeof(m.payload.u64);
@@ -351,6 +355,7 @@ vhost_user_sock(struct virtio_user_dev *dev,
 
 		switch (req) {
 		case VHOST_USER_GET_FEATURES:
+		case VHOST_USER_GET_PROTOCOL_FEATURES:
 			if (msg.size != sizeof(m.payload.u64)) {
 				PMD_DRV_LOG(ERR, "Received bad msg size");
 				return -1;
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 7fb135f49..e45159ddd 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -151,8 +151,10 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
 		goto error;
 
-	/* Step 1: set features */
+	/* Step 1: negotiate protocol features & set features */
 	features = dev->features;
+
+
 	/* Strip VIRTIO_NET_F_MAC, as MAC address is handled in vdev init */
 	features &= ~(1ull << VIRTIO_NET_F_MAC);
 	/* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
@@ -417,13 +419,19 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
 	 1ULL << VIRTIO_NET_F_GUEST_TSO6	|	\
 	 1ULL << VIRTIO_F_IN_ORDER		|	\
 	 1ULL << VIRTIO_F_VERSION_1		|	\
-	 1ULL << VIRTIO_F_RING_PACKED)
+	 1ULL << VIRTIO_F_RING_PACKED		|	\
+	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
+
+#define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES		\
+	(1ULL << VHOST_USER_PROTOCOL_F_MQ)
 
 int
 virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		     int cq, int queue_size, const char *mac, char **ifname,
 		     int server, int mrg_rxbuf, int in_order, int packed_vq)
 {
+	uint64_t protocol_features = 0;
+
 	pthread_mutex_init(&dev->mutex, NULL);
 	strlcpy(dev->path, path, PATH_MAX);
 	dev->started = 0;
@@ -434,6 +442,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 	dev->mac_specified = 0;
 	dev->frontend_features = 0;
 	dev->unsupported_features = ~VIRTIO_USER_SUPPORTED_FEATURES;
+	dev->protocol_features = VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES;
 	parse_mac(dev, mac);
 
 	if (*ifname) {
@@ -446,6 +455,10 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		return -1;
 	}
 
+	if (!is_vhost_user_by_type(dev->path))
+		dev->unsupported_features |=
+			(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
+
 	if (!dev->is_server) {
 		if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER,
 					   NULL) < 0) {
@@ -460,6 +473,26 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 				     strerror(errno));
 			return -1;
 		}
+
+
+		if (dev->device_features &
+				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
+			if (dev->ops->send_request(dev,
+					VHOST_USER_GET_PROTOCOL_FEATURES,
+					&protocol_features))
+				return -1;
+
+			dev->protocol_features &= protocol_features;
+
+			if (dev->ops->send_request(dev,
+						VHOST_USER_SET_PROTOCOL_FEATURES,
+						&dev->protocol_features))
+				return -1;
+
+			if (!(dev->protocol_features &
+						(1ULL << VHOST_USER_PROTOCOL_F_MQ)))
+				dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
+		}
 	} else {
 		/* We just pretend vhost-user can support all these features.
 		 * Note that this could be problematic that if some feature is
@@ -469,6 +502,8 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
 	}
 
+
+
 	if (!mrg_rxbuf)
 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MRG_RXBUF);
 
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index 3b6b6065a..56e638f8a 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -40,6 +40,9 @@ struct virtio_user_dev {
 	uint64_t	device_features; /* supported features by device */
 	uint64_t	frontend_features; /* enabled frontend features */
 	uint64_t	unsupported_features; /* unsupported features mask */
+	uint64_t	protocol_features; /* negotiated protocol features
+					    * (Vhost-user only)
+					    */
 	uint8_t		status;
 	uint16_t	port_id;
 	uint8_t		mac_addr[RTE_ETHER_ADDR_LEN];
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 798f191c3..ccb5a18e2 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -68,6 +68,7 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 	int connectfd;
 	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
 	struct virtio_hw *hw = eth_dev->data->dev_private;
+	uint64_t protocol_features;
 
 	connectfd = accept(dev->listenfd, NULL, NULL);
 	if (connectfd < 0)
@@ -81,6 +82,24 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 		return -1;
 	}
 
+	if (dev->device_features &
+			(1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
+		if (dev->ops->send_request(dev,
+					VHOST_USER_GET_PROTOCOL_FEATURES,
+					&protocol_features))
+			return -1;
+
+		dev->protocol_features &= protocol_features;
+
+		if (dev->ops->send_request(dev,
+					VHOST_USER_SET_PROTOCOL_FEATURES,
+					&dev->protocol_features))
+			return -1;
+	}
+
+	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)))
+		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
+
 	dev->device_features |= dev->frontend_features;
 
 	/* umask vhost-user unsupported features */
-- 
2.26.2