HHVM FastCGI configuration problems - ProxyPass failed

Question

I am on Ubuntu 12.04, running on Vagrant. Apache 2.2.22

I am trying to test my application on hhvm. I configured everything after that: https://github.com/facebook/hhvm/wiki/fastcgi

After adding part of the fastcgi module to my vhost configuration, I started to get 404 not found error. Then I found out that I need to use ProxyPassMatch. After adding the ProxyPassMatch line, I started getting 500 Internal Error. My apache log shows this:

[warn] proxy: No protocol handler was valid for the URL /index.php. If you are using a DSO version of mod_proxy, make sure the proxy submodules are included in the configuration using LoadModule.

All modules are included.

Here is my vhost configuration:

ServerAdmin webmaster@localhost
DocumentRoot /opt/myapp/www/
ServerName myapp.demo
ServerAlias myapp.demo

ErrorLog  /var/log/apache2/myapp.demo-error_log
CustomLog /var/log/apache2/myapp.demo-access_log common
ProxyPassMatch ^/(.*\.php(/.*)?)$ fcgi://127.0.0.1:9000/opt/myapp/public/$1

<IfModule mod_fastcgi.c>

    <FilesMatch \.php$>
                    SetHandler hhvm-php-extension
    </FilesMatch>

    <FilesMatch \.hh$>
            SetHandler hhvm-hack-extension
    </FilesMatch>

    Alias /hhvm /hhvm
    Action hhvm-php-extension /hhvm virtual
    Action hhvm-hack-extension /hhvm virtual

    FastCgiExternalServer /hhvm -host 127.0.0.1:9000 -pass-header Authorization -idle-timeout 300

</IfModule>

Thank!