Have the caller indicate its buffer size, provide a means to query the
needed size, don't ignore the upper halves of type code and instance,
and don't copy partial data.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>