[dpdk-dev] [PATCH v3] net/virtio-user: fix multiple queues fail in server mode

[zhiyong.yang@intel.com]

This patch fixes multiple queues failure when virtio-user works in
server mode.

This patch adds feature negotiation in the processing of virtio-user
connection and enables multiple-queue pairs.

Fixes: bd8f50a45d0f ("net/virtio-user: support server mode")
Cc: stable@dpdk.org

Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
---

Changes in V3:
1. virtio_user_handle_mq is redefined as extern instead of static.
2. add to call virtio_user_handle_mq in virtio_user_server_reconnect. 

Changes in V2:
1. fix a comment typo.
2. add feature negotiation in the processing of reconnection.

 drivers/net/virtio/virtio_user/vhost_user.c      |  3 +++
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 18 ++++++++++------
 drivers/net/virtio/virtio_user/virtio_user_dev.h |  1 +
 drivers/net/virtio/virtio_user_ethdev.c          | 27 ++++++++++++++++++++++++
 4 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c
index a6df97a00..93e4d9213 100644
--- a/drivers/net/virtio/virtio_user/vhost_user.c
+++ b/drivers/net/virtio/virtio_user/vhost_user.c
@@ -263,6 +263,9 @@ vhost_user_sock(struct virtio_user_dev *dev,
 
 	PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
 
+	if (dev->is_server && vhostfd < 0)
+		return -1;
+
 	msg.request = req;
 	msg.flags = VHOST_USER_VERSION;
 	msg.size = 0;
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 38b8bc90d..505f2ea5e 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -435,7 +435,7 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
 		unlink(dev->path);
 }
 
-static uint8_t
+uint8_t
 virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
 {
 	uint16_t i;
@@ -447,11 +447,17 @@ virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
 		return -1;
 	}
 
-	for (i = 0; i < q_pairs; ++i)
-		ret |= dev->ops->enable_qp(dev, i, 1);
-	for (i = q_pairs; i < dev->max_queue_pairs; ++i)
-		ret |= dev->ops->enable_qp(dev, i, 0);
-
+	/* Server mode can't enable queue pairs if vhostfd is invalid,
+	 * always return 0 in this case.
+	 */
+	if (dev->vhostfd >= 0)  {
+		for (i = 0; i < q_pairs; ++i)
+			ret |= dev->ops->enable_qp(dev, i, 1);
+		for (i = q_pairs; i < dev->max_queue_pairs; ++i)
+			ret |= dev->ops->enable_qp(dev, i, 0);
+	} else if (!dev->is_server) {
+		ret = ~0;
+	}
 	dev->queue_pairs = q_pairs;
 
 	return ret;
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index ade727e46..784f4752e 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -48,4 +48,5 @@ int virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 			 int cq, int queue_size, const char *mac, char **ifname);
 void virtio_user_dev_uninit(struct virtio_user_dev *dev);
 void virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx);
+uint8_t virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs);
 #endif
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 4e7b3c34f..e53d8f996 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -30,6 +30,7 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 	int ret;
 	int flag;
 	int connectfd;
+	uint64_t features = dev->device_features;
 	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
 
 	connectfd = accept(dev->listenfd, NULL, NULL);
@@ -37,6 +38,25 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 		return -1;
 
 	dev->vhostfd = connectfd;
+	if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
+				   &dev->device_features) < 0) {
+		PMD_INIT_LOG(ERR, "get_features failed: %s",
+			     strerror(errno));
+		return -1;
+	}
+
+	features &= ~dev->device_features;
+	/* For following bits, vhost-user doesn't really need to know */
+	features &= ~(1ull << VIRTIO_NET_F_MAC);
+	features &= ~(1ull << VIRTIO_NET_F_CTRL_VLAN);
+	features &= ~(1ull << VIRTIO_NET_F_CTRL_MAC_ADDR);
+	features &= ~(1ull << VIRTIO_NET_F_STATUS);
+	if (features)
+		PMD_INIT_LOG(ERR, "WARNING: Some features 0x%" PRIx64 "are not supported by vhost-user!",
+			     features);
+
+	dev->features &= dev->device_features;
+
 	flag = fcntl(connectfd, F_GETFD);
 	fcntl(connectfd, F_SETFL, flag | O_NONBLOCK);
 
@@ -44,6 +64,13 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 	if (ret < 0)
 		return -1;
 
+	if (dev->queue_pairs > 1) {
+		ret = virtio_user_handle_mq(dev, dev->queue_pairs);
+		if (ret != 0) {
+			PMD_INIT_LOG(ERR, "Fails to enable multi-queue pairs!");
+			return -1;
+		}
+	}
 	if (eth_dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC) {
 		if (rte_intr_disable(eth_dev->intr_handle) < 0) {
 			PMD_DRV_LOG(ERR, "interrupt disable failed");
-- 
2.14.3