Re: [PATCH resend v2 0/3] virt: Add vboxguest driver for Virtual Box Guest integration
From: Hans de Goede
Date: Tue Nov 28 2017 - 05:01:53 EST
Hi,
On 27-11-17 20:44, Larry Finger wrote:
On 11/26/2017 09:12 AM, Hans de Goede wrote:
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.
Hans,
I have finished reviewing the commits for vboxguest. Most of my comments are minor.
Thank you for the review!
I did have two problems when I tried to build these commits and the one that creates vboxsf.
The more serious one is that it is possible to build vboxguest without vboxvideo. When that happens, a non-privileged user cannot start X. As I say in the review, > I think that combination does not make sense and should not be allowed.
vboxguest and vboxvideo are completely independent at least from the kernel pov,
I do not believe that making them depend on each other makes sense.
AFAIK a non-privileged user cannot start X without vboxvideo at all, independent
of vboxguest being build or not. Falling back to vesa modesetting always requires
Xorg to be suid root, or the user to be privileged.
TL;DR: I can add a dependency between the 2, but I would rather not.
When the system is booted, vboxsf is not loaded, and the shared folders are not automounted. Of course, that issue is not germane to these patches, but will be important when vboxsf is merged.
Hmm, I mount a couple of shares from rc.local (I don't use vbox' automount as I
want to specify a uid for the files) and as soon as mount.vboxsf gets executed
the vboxsf module gets auto-loaded as the module contains:
MODULE_ALIAS_FS("vboxsf");
AFAIK the communication of which volumes to automount is done through vboxguest,
anyways I will look into this before submitting vboxsf, in the worst case
we need to drop a modprobe.conf.d/vboxguest.conf file which has a postinst vboxguest
which loads vboxsf.
Regards,
Hans