[dpdk-dev] [PATCH 4/6] net/virtio-user: fix device features for server mode

[Tiwei Bie <tiwei.bie@intel.com>]

We need to save the supported frontend features (which won't be
announced by vhost backend), otherwise we will lost them when the
connection to vhost-user backend is established in server mode.

Fixes: 201a41651715 ("net/virtio-user: fix multiple queues fail in server mode")
Cc: stable@dpdk.org

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 8 +++++---
 drivers/net/virtio/virtio_user/virtio_user_dev.h | 1 +
 drivers/net/virtio/virtio_user_ethdev.c          | 2 ++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index be70414a1..44e093eb7 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -421,6 +421,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 	dev->queue_pairs = 1; /* mq disabled by default */
 	dev->queue_size = queue_size;
 	dev->mac_specified = 0;
+	dev->frontend_features = 0;
 	dev->unsupported_features = 0;
 	parse_mac(dev, mac);
 
@@ -468,7 +469,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 	}
 
 	if (dev->mac_specified) {
-		dev->device_features |= (1ull << VIRTIO_NET_F_MAC);
+		dev->frontend_features |= (1ull << VIRTIO_NET_F_MAC);
 	} else {
 		dev->device_features &= ~(1ull << VIRTIO_NET_F_MAC);
 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MAC);
@@ -478,7 +479,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		/* device does not really need to know anything about CQ,
 		 * so if necessary, we just claim to support CQ
 		 */
-		dev->device_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
+		dev->frontend_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
 	} else {
 		dev->device_features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
 		/* Also disable features depends on VIRTIO_NET_F_CTRL_VQ */
@@ -499,8 +500,9 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 
 	/* The backend will not report this feature, we add it explicitly */
 	if (is_vhost_user_by_type(dev->path))
-		dev->device_features |= (1ull << VIRTIO_NET_F_STATUS);
+		dev->frontend_features |= (1ull << VIRTIO_NET_F_STATUS);
 
+	dev->device_features |= dev->frontend_features;
 	dev->device_features &= VIRTIO_USER_SUPPORTED_FEATURES;
 	dev->unsupported_features |= ~VIRTIO_USER_SUPPORTED_FEATURES;
 
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index d6e0e137b..c42ce5d4b 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -33,6 +33,7 @@ struct virtio_user_dev {
 				   * and will be sync with device
 				   */
 	uint64_t	device_features; /* supported features by device */
+	uint64_t	frontend_features; /* enabled frontend features */
 	uint64_t	unsupported_features; /* unsupported features mask */
 	uint8_t		status;
 	uint16_t	port_id;
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 2100e43db..c419d5b9d 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -43,6 +43,8 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 		return -1;
 	}
 
+	dev->device_features |= dev->frontend_features;
+
 	/* umask vhost-user unsupported features */
 	dev->device_features &= ~(dev->unsupported_features);
 
-- 
2.19.1