virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x

VirtualBox 6.0.x has a new feature where the guest kernel driver passes
info about the origin of the request (e.g. userspace or kernelspace) to
the hypervisor.

If we do not pass this information then when running the 6.0.x userspace
guest-additions tools on a 6.0.x host, some requests will get denied
with a VERR_VERSION_MISMATCH error, breaking vboxservice.service and
the mounting of shared folders marked to be auto-mounted.

This commit implements passing the requestor info to the host, fixing this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt: Add vboxguest driver for Virtual Box Guest integration

This commit adds a driver for the Virtual Box Guest PCI device used in
Virtual Box virtual machines. Enabling this driver will add support for
Virtual Box Guest integration features such as copy-and-paste, seamless
mode and OpenGL pass-through.

This driver also offers vboxguest IPC functionality which is needed
for the vboxfs driver which offers folder sharing support.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>