[dpdk-stable] [PATCH v3 5/6] net/virtio-user: don't assume vhost status feature

[Adrian Moreno]

There are some status reads and updates that need to happen before the
protocol features are negotiated. Therefore, assuming the backend does
support this feature can lead to failures.

On server mode, do not assume the backend supports
VHOST_USER_PROTOCOL_F_STATUS. Activate it back on reconnection and
cleare it on disconnection.

Fixes: 57912824615f ("net/virtio-user: support vhost status setting")
Cc: maxime.coquelin at redhat.com
Cc: stable at dpdk.org

Signed-off-by: Adrian Moreno <amorenoz at redhat.com>
---
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 6 ++++++
 drivers/net/virtio/virtio_user_ethdev.c          | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 36e5619df..053f0267c 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -523,6 +523,12 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		 * later.
 		 */
 		dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
+
+		/* We cannot assume VHOST_USER_PROTOCOL_F_STATUS is supported
+		 * until it's negotiated
+		 */
+		dev->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_STATUS);
 	}
 
 
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 97ddc5651..142bdc0bd 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -92,6 +92,9 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 					&protocol_features))
 			return -1;
 
+		/* Offer VHOST_USER_PROTOCOL_F_STATUS */
+		dev->protocol_features |=
+			(1ULL << VHOST_USER_PROTOCOL_F_STATUS);
 		dev->protocol_features &= protocol_features;
 
 		if (dev->ops->send_request(dev,
@@ -168,6 +171,11 @@ virtio_user_delayed_handler(void *param)
 		if (dev->vhostfd >= 0) {
 			close(dev->vhostfd);
 			dev->vhostfd = -1;
+			/* Until the featuers are negotiated again, don't assume
+			 * the backend supports VHOST_USER_PROTOCOL_F_STATUS
+			 */
+			dev->protocol_features &=
+				~(1ULL << VHOST_USER_PROTOCOL_F_STATUS);
 		}
 		eth_dev->intr_handle->fd = dev->listenfd;
 		rte_intr_callback_register(eth_dev->intr_handle,
-- 
2.26.2