I have a custom post type called `portfolio` and a taxonomy called `locations`. In the taxonomy I have various terms, like `paris, berlin, london` etc. 

How can I get only the posts which are related to one term, e.g. `paris`?

I am trying the following code, yet it gives me the ALL the posts of the taxonomy `portfolio` and not just of one term:

    $args = array(
  	    'post_type' => 'portfolio',
	    'locations' => 'paris'
    );
    $my_query = new WP_Query( $args );

    if( $my_query->have_posts() ) {
        while ($my_query->have_posts()) : $my_query->the_post(); ?>
            <p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
    <?php
        endwhile;
    }
    wp_reset_query();