[PATCH resend v2 0/3] virt: Add vboxguest driver for Virtual Box Guest integration

[Hans de Goede]

Here is resend of v2 of my cleaned up version of the VirtualBox vboxguest
driver, rebased on top of current the master from Linus.

Note there currently is an issue with vboxvideo in the current master from
Linus, this is fixed by this patch:
https://patchwork.freedesktop.org/patch/189812/

Once this is merged, I will do some further cleanups on the vboxsf driver
and also submit that upstream, if people want to test it before then, here
is a version which applies on top of this series:
https://github.com/jwrdegoede/linux-sunxi/commit/7f18b741945de3ae09ca8f1a9e48456ce32986c9

Changes in v2:
-Change all uapi headers to kernel coding style: Drop struct and enum typedefs
 make type and struct-member names all lowercase, enum values all uppercase.
-Remove unused struct type declarations from some headers (shaving of another
 1000 lines)
-Remove or fixup doxygen style comments
-Get rid of CHECK macros, use a function taking in_ and out_size args instead
-Some other small codyingstyle fixes
-Split into multiple patches

Here is (part of) the v1 cover-letter which is still relevant:

VirtualBox upstream has declared the ioctl API for the /dev/vboxguest device
as being stable now, so once this passes review this is ready for merging.

I'm only submitting the vboxguest driver for now, as the vboxsf driver
depends on this and it easier to first just get the vboxguest driver
upstream.

I've removed all depenencies on vbox's OS-independent runtime and
the runtime itself, reducing the vboxguest driver from 100000+ lines
of code to aprox. 4300 lines. This reduces the non debug vboxguest.ko
size from 450kB to less then 100 kB. I've also cleaned up various other
warts such as doing hardware init in module_init rather then in a
pci_probe callback.

The vboxguest driver introduces a new userspace API + ABI in the form
of ioctls on a character device. VirtualBox upstream not willing to
commit to keeping this ABI stable was one of the things which has
kept this driver driver out of mainline sofar. I've been talking to
VirtualBox upstream about mainlining the guest drivers and VirtualBox
upstream has agreed to consider the userspace ABI stable and only
extend it in a backwards compatible manner from now on.

Regards,

Hans