These lines are crucial to make it work (in php.ini):
zend_extension=/usr/lib/php/extensions/no-debug-non-zts-20121212/xdebug.so
xdebug.remote_autostart = 1 # <-------- THIS
xdebug.remote_enable = 1 # <----------- AND THIS
Without these lines xdebug will never work on phpstorm ;)