Apache：如何仅在根目录中启用php文件？

我的任务是只在根目录中启用php文件。我不想使用.htaccess文件，因为根据apache文档，它会降低性能。我尝试用正则表达式来解决它。
httpd.conf的部分内容：

…
<Directory />
   Options Includes 
   AllowOverride none
   Order Allow,Deny
</Directory>
<Directory ~ "/path/to/site/dir/$"> 
   <Files ~ "\.php$"> 
      Allow from all
   </Files>
</Directory>
…

NameVirtualHost *:80
<VirtualHost *:80>
    DocumentRoot "/path/to/site/dir/"
    ServerName example.com
    ServerAlias example.com
    ErrorLog "/path/to/site/dir/error.log"
    CustomLog "/path/to/site/dir /access.log" common
    <FilesMatch \.(js|css|png|ttf|gif)$> 
        Allow from all
    </FilesMatch>
    <FilesMatch "(file1|file2)\.php$"> 
        Allow from all
    </FilesMatch>
</VirtualHost>

…
选项包括
不允许超限
命令允许，拒绝
通融
…

httpd-vhosts.conf内容：

…
<Directory />
   Options Includes 
   AllowOverride none
   Order Allow,Deny
</Directory>
<Directory ~ "/path/to/site/dir/$"> 
   <Files ~ "\.php$"> 
      Allow from all
   </Files>
</Directory>
…

NameVirtualHost *:80
<VirtualHost *:80>
    DocumentRoot "/path/to/site/dir/"
    ServerName example.com
    ServerAlias example.com
    ErrorLog "/path/to/site/dir/error.log"
    CustomLog "/path/to/site/dir /access.log" common
    <FilesMatch \.(js|css|png|ttf|gif)$> 
        Allow from all
    </FilesMatch>
    <FilesMatch "(file1|file2)\.php$"> 
        Allow from all
    </FilesMatch>
</VirtualHost>

NameVirtualHost*：80
DocumentRoot“/path/to/site/dir/”
ServerName example.com
ServerAlias example.com
ErrorLog“/path/to/site/dir/error.log”
CustomLog“/path/to/site/dir/access.log”通用
通融
通融

此配置甚至不适用于根目录中的php文件。如何修改配置？
同时应工作地址：example.com/（不含php文件）