If user forgets to provide any backend types for '-netdev' in qemu CLI,
It triggers seg fault.
e.g.
Expected:
$ qemu -netdev id=net0
qemu-system-x86_64: Parameter 'type' is missing
Actual:
$ qemu -netdev id=net0
Segmentation fault (core dumped)
Fixes: 547203ead4327 ("net: List available netdevs with "-netdev help")
Reviewed-by: Thomas Huth <thuth@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Lin Ma <lma@suse.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
8b43f964f9