Now that zero page checking is done on the multifd sender threads by
default, we still provide an option for backward compatibility. This
change adds a qtest migration test case to set the zero-page-detection
option to "legacy" and run multifd migration with zero page checking on the
migration main thread.
Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240311180015.3359271-8-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>