How to inject standard WordPress pagination into WP_Query() loop?

Question

WordPress

There is a need on the site, on the index.php page to display articles from a certain category in a cycle. That is, there should be two loops on one page: one is standard, and the second is done using WP_Query (). In general, I'm stuck with pagination for the second one. Very weak in php. Perhaps someone has already encountered this problem and has a solution, please share.

<?php	
        $query = new WP_Query('cat=17');// вывод постов из категории с id=17
        if ($query->have_posts()) {
           	while ($query->have_posts()) { $query->the_post();
          ?>	
          <div class="posts">
            <?php if ( function_exists( 'add_theme_support' ) )         
the_post_thumbnail( array(250,9999), array('class' => 'imgmainpost') ); ?>						<h1 class="mainpage"><?php the_title(); ?></h1>
          </div>
        <?php }
        wp_reset_postdata();//сбрасываем переменную $post
        }
        ?>

And here is the pagination, which must be skillfully screwed into this cycle:

<div class="pagenavi">
        <?php if (function_exists('wp_corenavi')) wp_corenavi(); ?>
      </div>