When async unregister function is invoked in certain vhost event
callbacks (e.g. vring state change), deadlock may occur due to
recursive spinlock acquire. This patch uses trylock() primitive in
the unregister API to avoid deadlock.
Fixes: 78639d54563a ("vhost: introduce async enqueue registration API")
Cc: stable@dpdk.org
Signed-off-by: Patrick Fu <patrick.fu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
eb666d2408