VirtualBox Guest Shared Folder Support Coming To The Mainline Linux Kernel
Red Hat's Hans de Goede has been working to nurse many of the open-source VirtualBox drivers into the mainline kernel. The most recent is getting the "VBOXSF" driver queued into Greg KH's staging-linus branch. With it hitting the staging-linus branch overnight rather than staging-next, it's likely this VirtualBox VBOXSF driver is going to be sent in shortly as a fix/addition for the Linux 5.4 kernel cycle since there is little risk of regression.
The VBOXSF driver provides VirtualBox guest shared folder support. This kernel driver allows for folders exported by the host to be mounted under Linux and leverages IPC functions already provided by the existing VirtualBox guest Linux kernel driver. Hans de Goede cleaned up this driver from the original Oracle code into a state now that at least is ready for the staging area of the kernel.
The driver for the moment can be found in staging-linus and should be merged in short order.