лучше покажу location корневой


location / {
if ($request_filename != "index.php") {
rewrite ^(.*)$ /index.php break;
}

fastcgi_pass phpfarm;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME /home/vhost/site$fastcgi_script_name;
fastcgi_param DOCUMENT_ROOT /home/vhost/site;
include /etc/nginx/fastcgi_params;
proxy_redirect off;
client_body_buffer_size 128k;
fastcgi_connect_timeout 300;
fastcgi_send_timeout 300;
fastcgi_read_timeout 300;
fastcgi_buffer_size 4M;
fastcgi_buffers 4 4M;
fastcgi_busy_buffers_size 8M;
fastcgi_temp_file_write_size 50M;
fastcgi_param COBNUT_PATH /home/vhost/Cobnut/;
fastcgi_param SITE_PATH /home/vhost/site/;
fastcgi_param SITE_CONFIG_MAIN config/conf.ini;
fastcgi_param SITE_CONFIG_REWRITE config/prod.ini;
fastcgi_param SITE_NAME site;
fastcgi_param TMP /home/vhost/site/tmp/;
fastcgi_temp_path /home/vhost/site/tmp/;
fastcgi_param NGINX_UPLOAD_PROGRESS_URL http://site_name/progress;
track_uploads proxied 30s;
}

nginx + php-fpm.

Ваш вариант не подойдёт из за вот таких вот конфигов =(