Does GuestAdditions version depend on host

[aEugeneS111]

Does the appropriate version of guest additions depend on the host OS, or only on the guest? For example, if on a Windows host I install guest additions on a virtual machine, can I then use the same virtual drive on a Mac host? I know guest additions are installed in the guest, not the host. But presumably they provide an interface to the host, which makes me think they might be host-dependent. Any insight would be much appreciated.

Longer version:

I have one virtual machine, call it win1, on Windows host with Ubuntu guest. It has guest additions installed (in the Ubuntu guest). The virtual hard drive of that machine is called win1.vdi. It is located on a USB stick.

I've installed VirtualBox on my Mac. I've created another virtual machine, call it mac1, with Mac as host, Ubuntu as guest. Instead of creating a new hard drive, I plugged the USB stick into Mac and pointed VirtualBox to win1.vdi to use as an "existing hard drive".

Ubuntu itself booted fine, which isn't that surprising since after all VirtualBox, under both Windows and Mac, emulates the hardware Ubuntu needs to boot.

My question is, do the guest additions depend on the host OS? In other words, since I'm running on Mac now, should I uninstall the previous version of guest additions and install Mac-specific guest additions? I know that in any case guest additions would be installed from within the Ubuntu guest. But they provide an interface to the host platform (for example, for sharing folders). So is there a Mac-specific version of guest additions, or will the existing version (originally installed under Windows host) work fine?

[mpack]

Neither. It depends on the VirtualBox version, not the guest or host. In fact the GAs are not as tightly bound to VBox version as is (say) the extension pack, but it may be a problem for example if the GAs were newer than the VBox version, as they might expect features that aren't implemented yet (kinda depends on how much checking they do).