Commit Graph

128 Commits

Author SHA1 Message Date
Gerd Hoffmann
4478aa768c monitor: add vnc websockets
Add websockets bool to VncBasicInfo, report websocket server sockets,
flag websocket client connections.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:47 +01:00
Gerd Hoffmann
df88768460 monitor: add query-vnc-servers command
Add new query vnc qmp command, for the lack of better ideas just name it
"query-vnc-servers".  Changes over query-vnc:

 * It returns a list of vnc servers, so multiple vnc server instances
   are covered.
 * Each vnc server returns a list of server sockets.  Followup patch
   will use that to also report websockets.  In case we add support for
   multiple server sockets server sockets (to better support ipv4+ipv6
   dualstack) we can add them to the list too.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:47 +01:00
Gerd Hoffmann
2d29a4368c vnc: factor out qmp_query_client_list
so we can reuse it for the new vnc query command.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:47 +01:00
Gerd Hoffmann
e5f34cdd2d vnc: track & limit connections
Also track the number of connections in "connecting" and "shared" state
(in addition to the "exclusive" state).  Apply a configurable limit to
these connections.

The logic to apply the limit to connections in "shared" state is pretty
simple:  When the limit is reached no new connections are allowed.

The logic to apply the limit to connections in "connecting" state (this
is the state you are in *before* successful authentication) is
slightly different:  A new connect kicks out the oldest client which is
still in "connecting" state.  This avoids a easy DoS by unauthenticated
users by simply opening connections until the limit is reached.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:47 +01:00
Gerd Hoffmann
1d0d59fe29 vnc: allow binding servers to qemu consoles
This patch adds a display= parameter to the vnc options.  This allows to
bind a vnc server instance to a specific display, allowing to create a
multiseat setup with a vnc server for each seat.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:46 +01:00
Gerd Hoffmann
4db14629c3 vnc: switch to QemuOpts, allow multiple servers
This patch switches vnc over to QemuOpts, and it (more or less
as side effect) allows multiple vnc server instances.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:46 +01:00
Gerd Hoffmann
c8496408b4 vnc: add display id to acl names
In case the display id is "default" (which is the one you get if you
don't explicitly assign one) we keep the old name scheme, without
display, for backward compatibility reasons.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2015-01-22 11:18:46 +01:00
Gerd Hoffmann
14f7143ede vnc: remove unused DisplayState parameter, add id instead.
DisplayState isn't used anywhere, drop it.  Add the vnc server ID as
parameter instead, so it is possible to specify the server instance.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2015-01-22 11:18:46 +01:00
Gerd Hoffmann
d616ccc5dd vnc: remove vnc_display global
Replace with a vnc_displays list, so we can have multiple vnc server
instances.  Add vnc_server_find function to lookup a display by id.
With no id supplied return the first vnc server, for backward
compatibility reasons.

It is not possible (yet) to actually create multiple vnc server
instances.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2015-01-22 11:18:46 +01:00
Benjamin Herrenschmidt
34da30afa4 ui/vnc: Support shared surface for most pixman formats
At least all the ones I've tested. We make the assumption that
pixman is going to be better at conversion than we are.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[ kraxel: just hook up qemu_pixman_check_format ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-19 13:33:26 +01:00
ChenLiang
9d6b207047 vnc: return directly if no vnc client connected
graphic_hw_update and vnc_refresh_server_surface aren't
need to do when no vnc client connected. It can reduce
lock contention, because vnc_refresh will hold global big
lock two millisecond every three seconds.

Signed-off-by: ChenLiang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-10-28 11:51:04 +01:00
Petr Matousek
e6908bfe8e vnc: sanitize bits_per_pixel from the client
bits_per_pixel that are less than 8 could result in accessing
non-initialized buffers later in the code due to the expectation
that bytes_per_pixel value that is used to initialize these buffers is
never zero.

To fix this check that bits_per_pixel from the client is one of the
values that the rfb protocol specification allows.

This is CVE-2014-7815.

Signed-off-by: Petr Matousek <pmatouse@redhat.com>

[ kraxel: apply codestyle fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-10-28 11:51:04 +01:00
Peter Lieven
86152436eb ui/vnc: set TCP_NODELAY
we currently have the Nagle algorithm enabled for all outgoing VNC updates.
This may delay sensitive updates as mouse movements or typing in the console.
As we currently prepare all data in a buffer and then send as much as we can
disabling the Nagle algorithm should not cause big trouble. Well established
VNC servers like TightVNC set TCP_NODELAY as well.
A regular framebuffer update request generates exactly one framebuffer update
which should be pushed out as fast as possible.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-09-17 15:14:41 +02:00
Gerd Hoffmann
6365828003 vnc update fix
We need to remember has_updates for each vnc client.  Otherwise it might
happen that vnc_update_client(has_dirty=1) takes the first exit due to
output buffers not being flushed yet and subsequent calls with
has_dirty=0 take the second exit, wrongly assuming there is nothing to
do because the work defered in the first call is ignored.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
2014-07-25 09:43:31 +02:00
Stephan Kulow
07535a8902 fix full frame updates for VNC clients
If the client asks for !incremental frame updates, it has lost its content
so dirty doesn't matter - it has to see the full frame, so setting force_update

Signed-off-by: Stephan Kulow <coolo@suse.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
2014-07-25 09:42:56 +02:00
Peter Lieven
bea60dd767 ui/vnc: fix potential memory corruption issues
this patch makes the VNC server work correctly if the
server surface and the guest surface have different sizes.

Basically the server surface is adjusted to not exceed VNC_MAX_WIDTH
x VNC_MAX_HEIGHT and additionally the width is rounded up to multiple of
VNC_DIRTY_PIXELS_PER_BIT.

If we have a resolution whose width is not dividable by VNC_DIRTY_PIXELS_PER_BIT
we now get a small black bar on the right of the screen.

If the surface is too big to fit the limits only the upper left area is shown.

On top of that this fixes 2 memory corruption issues:

The first was actually discovered during playing
around with a Windows 7 vServer. During resolution
change in Windows 7 it happens sometimes that Windows
changes to an intermediate resolution where
server_stride % cmp_bytes != 0 (in vnc_refresh_server_surface).
This happens only if width % VNC_DIRTY_PIXELS_PER_BIT != 0.

The second is a theoretical issue, but is maybe exploitable
by the guest. If for some reason the guest surface size is bigger
than VNC_MAX_WIDTH x VNC_MAX_HEIGHT we end up in severe corruption since
this limit is nowhere enforced.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-07-01 13:26:40 +02:00
Peter Lieven
f9a70e7939 ui/vnc: limit client_cut_text msg payload size
currently a malicious client could define a payload
size of 2^32 - 1 bytes and send up to that size of
data to the vnc server. The server would allocated
that amount of memory which could easily create an
out of memory condition.

This patch limits the payload size to 1MB max.

Please note that client_cut_text messages are currently
silently ignored.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-07-01 13:26:40 +02:00
Wenchao Xia
fb6ba0d525 qapi event: convert VNC events
Since VNC_CONNECTED, VNC_DISCONNECTED, VNC_INITIALIZED share some
common functions, convert them in one patch.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23 11:12:28 -04:00
Wenchao Xia
a589569f2f qapi: adjust existing defines
In order to let event defines use existing types later, instead of
redefine new ones, some old type defines for spice and vnc are changed,
and BlockErrorAction is moved from block.h to qapi schema. Note that
BlockErrorAction is not merged with BlockdevOnError.

At this point, VncInfo is not made a child of VncBasicInfo, because
VncBasicInfo has mandatory fields where VncInfo makes them optional.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23 11:01:25 -04:00
Gerd Hoffmann
eb214ff8ef vnc: fix screen updates
Bug was added by 38ee14f4f3.
vnc_jobs_join call is missing in one code path.

Reported-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-06-19 12:48:07 +02:00
Markus Armbruster
c14e98479b vnc: Drop superfluous conditionals around g_strdup()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-06-19 12:48:07 +02:00
Markus Armbruster
64641d8764 vnc: Drop superfluous conditionals around g_free()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-06-19 12:48:07 +02:00
Gerd Hoffmann
2deb4acc7c input/vnc: use kbd delays in press_key
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-06-04 08:40:42 +02:00
Gerd Hoffmann
4006617552 vnc: add trace events for key events
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-06-02 16:29:01 +02:00
Gerd Hoffmann
cf864569cd vnc: refuse to set a password with VNC_AUTH_NONE
Current code silently changes the authentication settings
in case you try to set a password without password authentication
turned on.  This is bad.  Return an error instead.

If we want allow changing auth settings at runtime this should
be done explicitly using a separate monitor command, not as
side effect of set_passwd.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-06-02 16:29:01 +02:00
Cole Robinson
027a79c373 vnc: Remove default_mon usage
These errors don't seem user initiated, so forcibly printing to the
monitor doesn't seem right. Just use error_report.

Cc: Anthony Liguori <aliguori@amazon.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:58 -04:00
Peter Lieven
2f487a3d40 ui/vnc: fix vmware VGA incompatiblities
this fixes invalid rectangle updates observed after commit 12b316d
with the vmware VGA driver. The issues occured because the server
and client surface update seems to be out of sync at some points
and the max width of the surface is not dividable by
VNC_DIRTY_BITS_PER_PIXEL (16).

Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-18 08:21:24 +01:00
Peter Lieven
e22492d332 ui/vnc: disable adaptive update calculations if not needed
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Peter Lieven
919372251c ui/vnc: optimize setting in vnc_dpy_update()
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Peter Lieven
863d7c9105 ui/vnc: optimize clearing in find_and_clear_dirty_height()
The following artifical test (just the bitmap operation part) running
vnc_update_client 65536 times on a 2560x2048 surface illustrates the
performance difference:

All bits clean - vnc_update_client_new: 0.07 secs
                 vnc_update_client_new2: 0.07 secs
                 vnc_update_client_old: 10.98 secs

All bits dirty - vnc_update_client_new: 11.26 secs
               - vnc_update_client_new2: 0.29 secs
                 vnc_update_client_old: 20.19 secs

Few bits dirty - vnc_update_client_new: 0.07 secs
               - vnc_update_client_new2: 0.07 secs
                 vnc_update_client_old: 10.98 secs

vnc_update_client_new2 shows the performance of vnc_update_client
with this patch added.

Comparing with the test run of the last patch the performance
is at least unchanged while it is significantly improved
for the all bits dirty case.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Peter Lieven
12b316d4c1 ui/vnc: optimize dirty bitmap tracking
vnc_update_client currently scans the dirty bitmap of each client
bitwise which is a very costly operation if only few bits are dirty.
vnc_refresh_server_surface does almost the same.
this patch optimizes both by utilizing the heavily optimized
function find_next_bit to find the offset of the next dirty
bit in the dirty bitmaps.

The following artifical test (just the bitmap operation part) running
vnc_update_client 65536 times on a 2560x2048 surface illustrates the
performance difference:

All bits clean - vnc_update_client_new: 0.07 secs
 vnc_update_client_old: 10.98 secs

All bits dirty - vnc_update_client_new: 11.26 secs
 vnc_update_client_old: 20.19 secs

Few bits dirty - vnc_update_client_new: 0.08 secs
 vnc_update_client_old: 10.98 secs

The case for all bits dirty is still rather slow, this
is due to the implementation of find_and_clear_dirty_height.
This will be addresses in a separate patch.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Peter Lieven
6cd859aa8a ui/vnc: derive cmp_bytes from VNC_DIRTY_PIXELS_PER_BIT
this allows for setting VNC_DIRTY_PIXELS_PER_BIT to different
values than 16 if desired.

Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Peter Lieven
b4c85ddcec ui/vnc: introduce VNC_DIRTY_PIXELS_PER_BIT macro
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Gerd Hoffmann
38ee14f4f3 vnc: fix use-after-free in vnc_update_client_sync
Spotted by Coverity:

876     static int vnc_update_client_sync(VncState *vs, int has_dirty)
877     {

(1) Event freed_arg:    "vnc_update_client(VncState *, int)" frees "vs".  [details]
Also see events:        [deref_arg]

878         int ret = vnc_update_client(vs, has_dirty);

(2) Event deref_arg:    Calling "vnc_jobs_join(VncState *)" dereferences freed pointer "vs". [details]
Also see events:        [freed_arg]

879         vnc_jobs_join(vs);
880         return ret;
881     }

Remove vnc_update_client_sync wrapper, replace it with an additional
argument to vnc_update_client, so we can so the sync properly in
vnc_update_client (i.e. skip it in case of a client disconnect).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2014-03-10 12:35:04 +01:00
Gerd Hoffmann
14768eba46 input: mouse: switch vnc ui to new core
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-05 09:52:02 +01:00
Gerd Hoffmann
8d447d10b7 input: keyboard: switch vnc ui to new core
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-05 09:50:18 +01:00
Michael Tokarev
2c8cf54957 vnc: use booleans for vnc_connect, vnc_listen_read and vnc_display_add_client
Some arguments to these functions are booleans - either by declaration,
or by actual usage, but sometimes value of 0 or 1 is passed for a bool,
and sometimes it is declared as int but a bool value, or true/false,
is passed to it instead.  Clean it up a bit.

Cc: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-21 22:52:50 +04:00
Lei Li
1483adcf6a vnc: Make ledstate comparison before modifiers updated
The ledstate should be compared before modifiers updated,
otherwise the ledstate would be the same as current_led_state.

Reported-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1368606040-11950-1-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-15 08:48:43 -05:00
Tim Hardeck
0057a0d590 TLS support for VNC Websockets
Added TLS support to the VNC QEMU Websockets implementation.
VNC-TLS needs to be enabled for this feature to be used.

The required certificates are specified as in case of VNC-TLS
with the VNC parameter "x509=<path>".

If the server certificate isn't signed by a rooth authority it needs to
be manually imported in the browser because at least in case of Firefox
and Chrome there is no user dialog, the connection just gets canceled.

As a side note VEncrypt over Websocket doesn't work atm because TLS can't
be stacked in the current implementation. (It also didn't work before)
Nevertheless to my knowledge there is no HTML 5 VNC client which supports
it and the Websocket connection can be encrypted with regular TLS now so
it should be fine for most use cases.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366727581-5772-1-git-send-email-thardeck@suse.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-03 12:04:57 -05:00
Lei Li
e7b2aaccd9 vnc: Adjust lock state sync logic with VNC_FEATURE_LED_STATE
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366867752-11578-4-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-29 08:28:51 -05:00
Lei Li
ab99e5c1d9 vnc: Support for LED state extension
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366867752-11578-3-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-29 08:28:51 -05:00
Lei Li
96f3d174bd vnc: Add SCROLL lock key to kbd_leds
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366867752-11578-2-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-29 08:28:50 -05:00
Gerd Hoffmann
5209089fcd console: zap ds arg from register_displaychangelistener
We don't have multiple DisplayStates any more,
so passing it in as argument is not needed.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-25 14:45:46 -05:00
Gerd Hoffmann
81c0d5a662 console: add qemu_console_is_*
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-16 09:26:20 +02:00
Gerd Hoffmann
0f7b2864d0 console: gui timer fixes
Make gui update rate adaption code in gui_update() actually work.
Sprinkle in a tracepoint so you can see the code at work.  Remove
the update rate adaption code in vnc and make vnc simply use the
generic bits instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-16 09:03:49 +02:00
Gerd Hoffmann
1dbfa00503 console: rename vga_hw_*, add QemuConsole param
Add QemuConsole parameter to vga_hw_*, so the interface allows to update
non-active consoles (the actual code can't handle this yet, see next
patch).  Passing NULL is allowed and updates the active console, like
the functions do today.

While touching all vga_hw_* calls anyway rename that to the functions to
hardware-neutral graphics_hw_*

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-16 09:03:48 +02:00
Stefan Hajnoczi
f9e8cacc55 oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()
The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-04-02 11:47:37 -04:00
Gerd Hoffmann
bc2ed9704f console: zap displaystate from dcl callbacks
Now that nobody depends on DisplayState in DisplayChangeListener
callbacks any more we can remove the parameter from all callbacks.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-03-18 10:21:59 +01:00
Gerd Hoffmann
d39fa6d86d vnc: stop using DisplayState
Rework DisplayStateListener callbacks to not use the DisplayState
any more.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-03-18 10:21:58 +01:00
Gerd Hoffmann
c12aeb860c console: rework DisplaySurface handling [dcl/ui side]
Replace the dpy_gfx_resize and dpy_gfx_setdata DisplayChangeListener
callbacks with a dpy_gfx_switch callback which notifies the ui code
when the framebuffer backing storage changes.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-03-18 10:21:58 +01:00