linux-toradex.git/drivers/input/misc/xen-kbdfront.c, branch v3.13.9

xen/pvhvm: If xen_platform_pci=0 is set don't blow up (v4).

2014-02-13T21:55:28+00:00

commit 51c71a3bbaca868043cc45b3ad3786dd48a90235 upstream.

The user has the option of disabling the platform driver:
00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01)

which is used to unplug the emulated drivers (IDE, Realtek 8169, etc)
and allow the PV drivers to take over. If the user wishes
to disable that they can set:

  xen_platform_pci=0
  (in the guest config file)

or
  xen_emul_unplug=never
  (on the Linux command line)

except it does not work properly. The PV drivers still try to
load and since the Xen platform driver is not run - and it
has not initialized the grant tables, most of the PV drivers
stumble upon:

input: Xen Virtual Keyboard as /devices/virtual/input/input5
input: Xen Virtual Pointer as /devices/virtual/input/input6M
------------[ cut here ]------------
kernel BUG at /home/konrad/ssd/konrad/linux/drivers/xen/grant-table.c:1206!
invalid opcode: 0000 [#1] SMP
Modules linked in: xen_kbdfront(+) xenfs xen_privcmd
CPU: 6 PID: 1389 Comm: modprobe Not tainted 3.13.0-rc1upstream-00021-ga6c892b-dirty #1
Hardware name: Xen HVM domU, BIOS 4.4-unstable 11/26/2013
RIP: 0010:[]  [] get_free_entries+0x2e0/0x300
Call Trace:
 [] ? evdev_connect+0x1e3/0x240
 [] gnttab_grant_foreign_access+0x2e/0x70
 [] xenkbd_connect_backend+0x41/0x290 [xen_kbdfront]
 [] xenkbd_probe+0x2f2/0x324 [xen_kbdfront]
 [] xenbus_dev_probe+0x77/0x130
 [] xenbus_frontend_dev_probe+0x47/0x50
 [] driver_probe_device+0x89/0x230
 [] __driver_attach+0x9b/0xa0
 [] ? driver_probe_device+0x230/0x230
 [] ? driver_probe_device+0x230/0x230
 [] bus_for_each_dev+0x8c/0xb0
 [] driver_attach+0x19/0x20
 [] bus_add_driver+0x1a0/0x220
 [] driver_register+0x5f/0xf0
 [] xenbus_register_driver_common+0x15/0x20
 [] xenbus_register_frontend+0x23/0x40
 [] ? 0xffffffffa0014fff
 [] xenkbd_init+0x2b/0x1000 [xen_kbdfront]
 [] do_one_initcall+0x49/0x170

.. snip..

which is hardly nice. This patch fixes this by having each
PV driver check for:
 - if running in PV, then it is fine to execute (as that is their
   native environment).
 - if running in HVM, check if user wanted 'xen_emul_unplug=never',
   in which case bail out and don't load any PV drivers.
 - if running in HVM, and if PCI device 5853:0001 (xen_platform_pci)
   does not exist, then bail out and not load PV drivers.
 - (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=ide-disks',
   then bail out for all PV devices _except_ the block one.
   Ditto for the network one ('nics').
 - (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=unnecessary'
   then load block PV driver, and also setup the legacy IDE paths.
   In (v3) make it actually load PV drivers.

Reported-by: Sander Eikelenboom 
Reported-and-Tested-by: Fabio Fantoni 
Signed-off-by: Konrad Rzeszutek Wilk 
[v2: Add extra logic to handle the myrid ways 'xen_emul_unplug'
can be used per Ian and Stefano suggestion]
[v3: Make the unnecessary case work properly]
[v4: s/disks/ide-disks/ spotted by Fabio]
Reviewed-by: Stefano Stabellini 
Acked-by: Bjorn Helgaas  [for PCI parts]
Signed-off-by: Greg Kroah-Hartman

Input: remove use of __devinit

2012-11-24T08:05:19+00:00

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton 
Acked-by: Mark Brown 
Acked-by: Javier Martinez Canillas 
Signed-off-by: Dmitry Torokhov

xen-kbdfront: handle backend CLOSED without CLOSING

2012-10-30T13:29:07+00:00

Backend drivers shouldn't transistion to CLOSED unless the frontend is
CLOSED.  If a backend does transition to CLOSED too soon then the
frontend may not see the CLOSING state and will not properly shutdown.

So, treat an unexpected backend CLOSED state the same as CLOSING.

Acked-by: Dmitry Torokhov 
Signed-off-by: David Vrabel 
Signed-off-by: Konrad Rzeszutek Wilk

Xen: consolidate and simplify struct xenbus_driver instantiation

2012-01-04T22:01:17+00:00

The 'name', 'owner', and 'mod_name' members are redundant with the
identically named fields in the 'driver' sub-structure. Rather than
switching each instance to specify these fields explicitly, introduce
a macro to simplify this.

Eliminate further redundancy by allowing the drvname argument to
DEFINE_XENBUS_DRIVER() to be blank (in which case the first entry from
the ID table will be used for .driver.name).

Also eliminate the questionable xenbus_register_{back,front}end()
wrappers - their sole remaining purpose was the checking of the
'owner' field, proper setting of which shouldn't be an issue anymore
when the macro gets used.

v2: Restore DRV_NAME for the driver name in xen-pciback.

Signed-off-by: Jan Beulich 
Cc: Jens Axboe 
Cc: Dmitry Torokhov 
Cc: Florian Tobias Schandinat 
Cc: Ian Campbell 
Cc: David S. Miller 
Signed-off-by: Konrad Rzeszutek Wilk

Input: xen-kbdfront - enable driver for HVM guests

2011-07-05T02:31:19+00:00

Signed-off-by: Stefano Stabellini 
Acked-by: Konrad Rzeszutek Wilk 
Signed-off-by: Dmitry Torokhov

Input: xen-kbdfront - fix mouse getting stuck after save/restore

2011-04-18T17:17:45+00:00

Mouse gets "stuck" after restore of PV guest but buttons are in working
condition.

If driver has been configured for ABS coordinates at start it will get
XENKBD_TYPE_POS events and then suddenly after restore it'll start getting
XENKBD_TYPE_MOTION events, that will be dropped later and they won't get
into user-space.

Regression was introduced by hunk 5 and 6 of
5ea5254aa0ad269cfbd2875c973ef25ab5b5e9db
("Input: xen-kbdfront - advertise either absolute or relative
coordinates").

Driver on restore should ask xen for request-abs-pointer again if it is
available. So restore parts that did it before 5ea5254.

Acked-by: Olaf Hering 
Signed-off-by: Igor Mammedov 
[v1: Expanded the commit description]
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Dmitry Torokhov

Input: xen-kbdfront - move to drivers/input/misc

2011-03-17T06:26:01+00:00

drivers/input is reserved for input core code and input handlers with
drivers belonging to one of the sub-directories.

Signed-off-by: Dmitry Torokhov