ublk zero copy usually requires to set dma and segment parameter correctly,
so hard-code null target's dma & segment parameter in non-default value,
and verify if they are setup correctly by ublk driver.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250327095123.179113-12-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>