virt: vbox: utils: fix all kernel-doc warnings

Use kernel-doc format for functions that have comments that begin
with "/**".
This prevents 6 kernel-doc warnings.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231222052521.14333-3-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt: vbox: Do not use wait_event_interruptible when called from kernel context

Do not use wait_event_interruptible when vbg_hgcm_call() gets called from
kernel-context, such as it being called by the vboxsf filesystem code.

This fixes some filesystem related system calls on shared folders
unexpectedly failing with -EINTR.

Fixes: 0532a1b0d045 ("virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x")
Reported-by: Ludovic Pouzenc <bugreports@pouzenc.fr>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210121150754.147598-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt: vbox: Log unknown ioctl requests as error

Every now and then upstream adds new ioctls without notifying us,
log unknown ioctl requests as an error to catch these.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200709120858.63928-8-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt: vbox: Use fallthrough;

Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/

And by hand:

drivers/virt/vboxguest/vboxguest_core.c has a fallthrough comment outside
of an #ifdef block that causes gcc to emit a warning if converted in-place.

So move the new fallthrough; inside the containing #ifdef/#endif too.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/68773b4cd82288b78ca6fcde8c43e249a025378a.1584040050.git.joe@perches.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt: vbox: Explicitly include linux/io.h to pick up various defs

Through a labyrinthian sequence of includes, usage of page_to_phys(),
virt_to_phys() and out*() is dependent on the include of asm/io.h in
x86's asm/realmode.h, which is included in x86's asm/acpi.h and thus by
linux/acpi.h. Explicitly include linux/io.h to break the dependency on
realmode.h so that a future patch can remove the realmode.h include from
acpi.h without breaking the build.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20191126165417.22423-8-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

virt: vbox: fix memory leak in hgcm_call_preprocess_linaddr

In hgcm_call_preprocess_linaddr memory is allocated for bounce_buf but
is not released if copy_form_user fails. In order to prevent memory leak
in case of failure, the assignment to bounce_buf_ret is moved before the
error check. This way the allocated bounce_buf will be released by the
caller.

Fixes: 579db9d45cb4 ("virt: Add vboxguest VMMDEV communication code")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20190930204223.3660-1-navid.emamdoost@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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: vbox: Use __get_free_pages instead of kmalloc for DMA32 memory

It is not possible to get DMA32 zone memory through kmalloc, causing
the vboxguest driver to malfunction due to getting memory above
4G which the PCI device cannot handle.

This commit changes the kmalloc calls where the 4G limit matters to
using __get_free_pages() fixing vboxguest not working on x86_64 guests
with more then 4G RAM.

Cc: stable@vger.kernel.org
Reported-by: Eloy Coto Pereiro <eloy.coto@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt: vbox: Add vbg_req_free() helper function

This is a preparation patch for fixing issues on x86_64 virtual-machines
with more then 4G of RAM, atm we pass __GFP_DMA32 to kmalloc, but kmalloc
does not honor that, so we need to switch to get_pages, which means we
will not be able to use kfree to free memory allocated with vbg_alloc_req.

While at it also remove a comment on a vbg_alloc_req call which talks
about Windows (inherited from the vbox upstream cross-platform code).

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

virt: vbox: Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES

Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES vbox status
codes, these are both used by the vboxsf (shared folder) code.

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

virt: Add vboxguest VMMDEV communication code

This commits adds a header describing the hardware interface for the
Virtual Box Guest PCI device used in Virtual Box virtual machines and
utility functions for talking to the Virtual Box hypervisor over this
interface.

These utility functions will used both by the vboxguest driver for the
PCI device which offers the /dev/vboxguest ioctl API and by 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>