[PATCH 2/2] net/virtio: fix notification area initialization

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Notification area is a Virtio feature that require to be
negotiated because not all devices support it. Currently,
it is tried to be initialized as soon as the backend
implements the callback, so it assumes all Vhost-vDPA
devices support it.

This patch skips calling the notification area map callback
if the device does not advertise its support.

Fixes: 0fd2782660c8 ("net/virtio-user: support notification area mapping")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 0b5db12886..b2e361ef3b 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -433,8 +433,9 @@ virtio_user_dev_init_notify(struct virtio_user_dev *dev)
 		dev->kickfds[i] = kickfd;
 	}
 
-	if (dev->ops->map_notification_area)
-		if (dev->ops->map_notification_area(dev))
+	if (dev->device_features & (1ULL << VIRTIO_F_NOTIFICATION_DATA))
+		if (dev->ops->map_notification_area &&
+				dev->ops->map_notification_area(dev))
 			goto err;
 
 	return 0;
-- 
2.44.0