wp_query select if have comments

You might try this:

add_filter( 'posts_where', 'filter_where' );
$query = new WP_Query($args);
remove_filter( 'posts_where', 'filter_where' );

where

function filter_where( $where="" ) {
    $where .= " AND comment_count > 0 ";
    return $where;
}

to get posts with comments.