net/vhost: support queue update

net/vhost: support queue update

The commit below changed the readiness condition of vhost device to fix
multi-queues issues showed with QEMU versions.

Now, the vhost device is ready when the first queue-pair is ready.
When more queues are being ready, the queue state callback will be
triggered to notify the vhost manager.

In case of Rx interrupt configuration, the vhost driver set the
kickfd queue file descriptor in order to be notified on Rx traffic.

So, when queue becomes ready, the kickfd may be changed and should be
updated in the Rx interrupt structure.

Update kickfd when the queue state callback is invoked.
Also update event notification when it is enabled by the user.

Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")

Suggested-by: Marvin Liu <yong.liu@intel.com>
Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>