vhost: fix missing virtqueue lock protection

This patch ensures virtqueue metadata are not being
modified while rte_vhost_vring_call() is executed.

Fixes: 6c299bb ("vhost: introduce vring call API")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>

lib/vhost/vhost.c

@@ -1291,11 +1291,15 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
 	if (!vq)
 		return -1;
 
+	rte_spinlock_lock(&vq->access_lock);
+
 	if (vq_is_packed(dev))
 		vhost_vring_call_packed(dev, vq);
 	else
 		vhost_vring_call_split(dev, vq);
 
+	rte_spinlock_unlock(&vq->access_lock);
+
 	return 0;
 }