[arch-general] Virtualbox guest additions on custom kernel

Hello all, I compiled my own custom kernel on a virtual machine and then I need to provide at my system the additions in order to have a compelete system. I tried to follow the https://wiki.archlinux.org/index.php/VirtualBox#Install_the_Guest_Additions but I catch an error on # modprobe -a vboxguest vboxsf vboxvideo FATAL: module vboxdrv not found And under /lib/modules/mykernel/ or /lib/modules/extra-mykernel I can't find the modules, do I compile by hands the module, any suggestions ? Hope this is the right place where ask, thanks in advance, Pietro