Add an usage for kernel submissions. Waiting for those are mandatory for
dynamic DMA-bufs.
As a precaution this patch also changes all occurrences where fences are
added as part of memory management in TTM, VMWGFX and i915 to use the
new value because it now becomes possible for drivers to ignore fences
with the WRITE usage.
v2: use "must" in documentation, fix whitespaces
v3: separate out some driver changes and better document why some
changes should still be part of this patch.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-5-christian.koenig@amd.com
Instead of distingting between shared and exclusive fences specify
the fence usage while adding fences.
Rework all drivers to use this interface instead and deprecate the old one.
v2: some kerneldoc comments suggested by Daniel
v3: fix a missing case in radeon
v4: rebase on nouveau changes, fix lockdep and temporary disable warning
v5: more documentation updates
v6: separate internal dma_resv changes from this patch, avoids to
disable warning temporary, rebase on upstream changes
v7: fix missed case in lima driver, minimize changes to i915_gem_busy_ioctl
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-3-christian.koenig@amd.com
This change adds the dma_resv_usage enum and allows us to specify why a
dma_resv object is queried for its containing fences.
Additional to that a dma_resv_usage_rw() helper function is added to aid
retrieving the fences for a read or write userspace submission.
This is then deployed to the different query functions of the dma_resv
object and all of their users. When the write paratermer was previously
true we now use DMA_RESV_USAGE_WRITE and DMA_RESV_USAGE_READ otherwise.
v2: add KERNEL/OTHER in separate patch
v3: some kerneldoc suggestions by Daniel
v4: some more kerneldoc suggestions by Daniel, fix missing cases lost in
the rebase pointed out by Bas.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-2-christian.koenig@amd.com
With very limited vram on svga3 it's difficult to handle all the surface
migrations. Without gbobjects, i.e. the ability to store surfaces in
guest mobs, there's no reason to support intermediate svga2 features,
especially because we can fall back to fb traces and svga3 will never
support those in-between features.
On svga3 we wither want to use fb traces or screen targets
(i.e. gbobjects), nothing in between. This fixes presentation on a lot
of fusion/esxi tech previews where the exposed svga3 caps haven't been
finalized yet.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: 2cd80dbd35 ("drm/vmwgfx: Add basic support for SVGA3")
Cc: <stable@vger.kernel.org> # v5.14+
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318174332.440068-5-zack@kde.org
Writes to SVGA_REG_CURSOR_MOBID did not wait for the buffers to be fully
populated. This sometimes results in the device not being aware of
the buffer when the cursor mob register was written.
Properly wait for the buffer to be fully populated before setting it
as a cursor mob.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: 485d98d472 ("drm/vmwgfx: Add support for CursorMob and CursorBypass 4")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318174332.440068-3-zack@kde.org
vmw_move assumed that buffers to be moved would always be
vmw_buffer_object's but after introduction of new placement for mob
pages that's no longer the case.
The resulting invalid read didn't have any practical consequences
because the memory isn't used unless the object actually is a
vmw_buffer_object.
Fix it by moving the cast to the spot where the results are used.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: f6be23264b ("drm/vmwgfx: Introduce a new placement for MOB page tables")
Reported-by: Chuck Lever III <chuck.lever@oracle.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318174332.440068-2-zack@kde.org
Initial version of guest backed objects in the host had some performance
issues that made using surface-dma's instead of direct copies faster.
Surface dma's force a migration to vram which at best is slow and at
worst is impossible (e.g. on svga3 where there's not enough vram
to migrate fb's to it).
Slowly migrate away from surface dma's to direct copies by limiting
their usage to systems with more than 32MB of vram.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-9-zack@kde.org
SVGAv3 deprecates legacy interrupts and adds support for MSI/MSI-X. With
MSI the driver visible side remains largely unchanged but with MSI-X
each interrupt gets delivered on its own vector.
Add support for MSI/MSI-X while preserving the old functionality for
SVGAv2. Code between the SVGAv2 and SVGAv3 is exactly the same, only
the number of available vectors changes, in particular between legacy
and MSI-X interrupts.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220307162412.1183049-1-zack@kde.org
Port of the vmwgfx to SVGAv3 lacked support for fencing. SVGAv3 removed
FIFO's and replaced them with command buffers and extra registers.
The initial version of SVGAv3 lacked support for most advanced features
(e.g. 3D) which made fences unnecessary. That is no longer the case,
especially as 3D support is being turned on.
Switch from FIFO commands and capabilities to command buffers and extra
registers to enable fences on SVGAv3.
Fixes: 2cd80dbd35 ("drm/vmwgfx: Add basic support for SVGA3")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-5-zack@kde.org
The results of the legacy display unit initialization were being silently
ignored. Unifying the selection of number of display units based
on whether the underlying device supports multimon makes it easier
to add error checking to all paths.
This makes the driver report the errors in ldu initialization paths
and try to recover from them.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-3-zack@kde.org
* Add support for CursorMob
* Add support for CursorBypass 4
* Refactor vmw_du_cursor_plane_atomic_update to be kms-helper-atomic
-- move BO mappings to vmw_du_cursor_plane_prepare_fb
-- move BO unmappings to vmw_du_cursor_plane_cleanup_fb
Cursor mobs are a new svga feature which enables support for large
cursors, e.g. large accessibility cursor on platforms with vmwgfx. It
also cleans up the cursor code and makes it more uniform with the rest
of modern guest backed objects support.
Signed-off-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-2-zack@kde.org
First backmerge into drm-misc-next. Required for more helpers backmerged,
and to pull in 5.17 (rc2).
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[airlied: add two missing Kconfig]
drm-misc-next for v5.18:
UAPI Changes:
- Fix invalid IN_FORMATS blob when plane->format_mod_supported is NULL.
Cross-subsystem Changes:
- Assorted dt bindings updates.
- Fix vga16fb vga checking on x86.
- Fix extra semicolon in rwsem.h's _down_write_nest_lock.
- Assorted small fixes to agp and fbdev drivers.
- Fix oops in creating a udmabuf with 0 pages.
- Hot-unplug firmware fb devices on forced removal
- Reqquest memory region in simplefb and simpledrm, and don't make the ioresource as busy.
Core Changes:
- Mock a drm_plane in drm-plane-helper selftest.
- Assorted bug fixes to device logging, dbi.
- Use DP helper for sink count in mst.
- Assorted documentation fixes.
- Assorted small fixes.
- Move DP headers to drm/dp, and add a drm dp helper module.
- Move the buddy allocator from i915 to common drm.
- Add simple pci and platform module init macros to remove a lot of boilerplate from some drivers.
- Support microsoft extension for HMDs and specialized monitors.
- Improve edid parser's deep color handling.
- Add type 7 timing support to edid parser.
- Add a weak backpointer to the ttm_bo from ttm_resource
- Add 3 eDP panels.
Driver Changes:
- Add support for HDMI and JZ4780 to ingenic.
- Add support for higher DP/eDP bitrates to nouveau.
- Assorted driver fixes to tilcdc, vmwgfx, sn65dsi83, meson, stm, panfrost, v3d, gma500, vc4, virtio, mgag200, ast, radeon, amdgpu, nouveau, various bridge drivers.
- Convert and revert exynos dsi support to bridge driver.
- Add vcc supply regulator support for sn65dsi83.
- More conversion of bridge/chipone-icn6211 to atomic.
- Remove conflicting fb's from stm, and add support for new hw version.
- Add device link in parade-ps8640 to fix suspend/resume.
- Update Boe-tv110c9m init sequence.
- Add wide screen support to AST2600.
- Fix omapdrm implicit dma_buf fencing.
- Add support for multiple overlay planes to vkms.
- Convert bridge/anx7625 to atomic, add HDCP support,
add eld support for audio, and fix HPD.
- Add driver for ChromeOS privacy screen.
- Handover display from firmware to vc4 more gracefully, and support nomodeset.
- Add flexible and ycbcr pixel formats to stm/ltdc.
- Convert exynos mipi dsi to atomic.
- Add initial dual core group GPUs support to panfrost.
- No longer add exclusive fence in amdgpu as shared fence.
- Add CSC and full range supoprt to vc4.
- Shutdown the display on system shutdown and unbind.
- Add Multi-Inno Technology MI0700S4T-6 simple panel.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/456a23c6-7324-7543-0c45-751f30ef83f7@linux.intel.com
A failing usercopy of the fence_rep object will lead to a stale entry in
the file descriptor table as put_unused_fd() won't release it. This
enables userland to refer to a dangling 'file' object through that still
valid file descriptor, leading to all kinds of use-after-free
exploitation scenarios.
Fix this by deferring the call to fd_install() until after the usercopy
has succeeded.
Fixes: c906965dee ("drm/vmwgfx: Add export fence to file descriptor support")
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmw_user_bo_lookup can fail to lookup user buffers, especially because
the buffer handles come from the userspace. The return value has
to be checked before the buffers are put back.
This was spotted by Dan's Smatch statick checker:
drivers/gpu/drm/vmwgfx/vmwgfx_bo.c:574 vmw_user_bo_synccpu_release()
error: uninitialized symbol 'vmw_bo'.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 8afa13a058 ("drm/vmwgfx: Implement DRIVER_GEM")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215200224.3693345-1-zack@kde.org
(cherry picked from commit 60c9ecd705)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Before the driver had screen targets support we had to disable explicit
bringup of its infrastructure because it was breaking screen objects
support.
Since the implementation of screen targets landed there hasn't been a
reason to explicitly disable it and the options were never used.
Remove of all that unused code.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: d80efd5cb3 ("drm/vmwgfx: Initial DX support")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215184147.3688785-3-zack@kde.org
(cherry picked from commit 11343099d5)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Old versions of the svga device used to export virtual vram, handling of
which was optimized on top of transparent hugepages support. Only very
old devices (OpenGL 2.1 support and earlier) used this code and at this
point performance differences are negligible.
Because the code requires very old hardware versions to run it has
been largely untested and unused for a long time.
Furthermore removal of the ttm hugepages support in:
commit 0d97950953 ("drm/ttm: remove ttm_bo_vm_insert_huge()")
broke the coherency mode in vmwgfx when running with hugepages.
Fixes: 0d97950953 ("drm/ttm: remove ttm_bo_vm_insert_huge()")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215184147.3688785-2-zack@kde.org
(cherry picked from commit 49d535d64d)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
On i386 size_t is of course 32bits and using long int throws warnings,
trivially fix it by using the dedicated size_t format.
This is enough to fix the following warning found by the kernel test
robot:
drivers/gpu/drm/vmwgfx/vmwgfx_gem.c: In function 'vmw_bo_print_info':
>> drivers/gpu/drm/vmwgfx/vmwgfx_gem.c:230:33: warning: format '%ld'
expects argument of type 'long int', but argument 4 has type 'size_t'
{aka 'unsigned int'} [-Wformat=]
230 | seq_printf(m, "\t\t0x%08x: %12ld bytes %s, type = %s",
| ~~~~^
| |
| long int
| %12d
231 | id, bo->base.base.size, placement, type);
| ~~~~~~~~~~~~~~~~~~
| |
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: 8afa13a058 ("drm/vmwgfx: Implement DRIVER_GEM")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215184147.3688785-1-zack@kde.org
(cherry picked from commit 72345114c9)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
vmw_user_bo_lookup can fail to lookup user buffers, especially because
the buffer handles come from the userspace. The return value has
to be checked before the buffers are put back.
This was spotted by Dan's Smatch statick checker:
drivers/gpu/drm/vmwgfx/vmwgfx_bo.c:574 vmw_user_bo_synccpu_release()
error: uninitialized symbol 'vmw_bo'.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 8afa13a058 ("drm/vmwgfx: Implement DRIVER_GEM")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215200224.3693345-1-zack@kde.org
Before the driver had screen targets support we had to disable explicit
bringup of its infrastructure because it was breaking screen objects
support.
Since the implementation of screen targets landed there hasn't been a
reason to explicitly disable it and the options were never used.
Remove of all that unused code.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: d80efd5cb3 ("drm/vmwgfx: Initial DX support")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215184147.3688785-3-zack@kde.org
Old versions of the svga device used to export virtual vram, handling of
which was optimized on top of transparent hugepages support. Only very
old devices (OpenGL 2.1 support and earlier) used this code and at this
point performance differences are negligible.
Because the code requires very old hardware versions to run it has
been largely untested and unused for a long time.
Furthermore removal of the ttm hugepages support in:
commit 0d97950953 ("drm/ttm: remove ttm_bo_vm_insert_huge()")
broke the coherency mode in vmwgfx when running with hugepages.
Fixes: 0d97950953 ("drm/ttm: remove ttm_bo_vm_insert_huge()")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215184147.3688785-2-zack@kde.org
On i386 size_t is of course 32bits and using long int throws warnings,
trivially fix it by using the dedicated size_t format.
This is enough to fix the following warning found by the kernel test
robot:
drivers/gpu/drm/vmwgfx/vmwgfx_gem.c: In function 'vmw_bo_print_info':
>> drivers/gpu/drm/vmwgfx/vmwgfx_gem.c:230:33: warning: format '%ld'
expects argument of type 'long int', but argument 4 has type 'size_t'
{aka 'unsigned int'} [-Wformat=]
230 | seq_printf(m, "\t\t0x%08x: %12ld bytes %s, type = %s",
| ~~~~^
| |
| long int
| %12d
231 | id, bo->base.base.size, placement, type);
| ~~~~~~~~~~~~~~~~~~
| |
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: 8afa13a058 ("drm/vmwgfx: Implement DRIVER_GEM")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215184147.3688785-1-zack@kde.org
Using MOBFMT_RANGE in the early days of guest backed objects was a major
performance win but that has changed a lot since. There's no more
a performance reason to use MOBFMT_RANGE. The device can/will still
profit from the pages being contiguous but marking them as MOBFMT_RANGE
no longer matters.
Benchmarks (e.g. heaven, valley) show that creating page tables
for mob memory is actually faster than using mobfmt ranges.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-12-zack@kde.org
The fb handle code assumes it deals with GEM objects. Because vmwgfx
buffer objects were not actually GEM objects we were not able to
implement that interface. Now that vmwgfx supports GEM buffer objects
we can trivially implement create_handle for buffer object backed
framebuffers.
Among others this gets IGT's kms_getfb test passing.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-6-zack@kde.org
This is initial change adding support for DRIVER_GEM to vmwgfx. vmwgfx
was written before GEM and has always used TTM. Over the years the
TTM buffers started inherting from GEM objects but vmwgfx never
implemented GEM making it quite awkward. We were directly setting
variables in GEM objects to not make DRM crash.
This change brings vmwgfx inline with other DRM drivers and allows us
to use a lot of DRM helpers which have depended on drivers with GEM
support.
Due to historical reasons vmwgfx splits the idea of a buffer and surface
which makes it a littly tricky since either one can be used in most
of our ioctl's which take user space handles. For now our BO's are
GEM objects and our surfaces are opaque objects which are backed by
GEM objects. In the future I'd like to combine those into a single
BO but we don't want to break any of our existing ioctl's so it will
take time to do it in a non-destructive way.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-5-zack@kde.org
Mob/GMR id resource manager was lacking the debug print callback
which meant that during memory errors we weren't getting the details
which are needed to fix those errors.
Kernel logs need to contain the information about used/max pages
by the Mob/GMR id resource manager as well as the maximum number
of id's they're allowed to allocate.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-3-zack@kde.org
vmwgfx shared very elaborate memory accounting with ttm. It was moved
from ttm to vmwgfx in change
f07069da6b ("drm/ttm: move memory accounting into vmwgfx v4")
but because of complexity it was hard to maintain. Some parts of the code
weren't freeing memory correctly and some were missing accounting all
together. While those would be fairly easy to fix the fundamental reason
for memory accounting in the driver was the ability to invoke shrinker
which is part of TTM code as well (with support for unified memory
hopefully coming soon).
That meant that vmwgfx had a lot of code that was either unused or
duplicating code from TTM. Removing this code also prevents excessive
calls to global swapout which were common during memory pressure
because both vmwgfx and TTM would invoke the shrinker when memory
usage reached half of RAM.
Fixes: f07069da6b ("drm/ttm: move memory accounting into vmwgfx v4")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-2-zack@kde.org
For larger (bigger than a page) and noncontiguous mobs we have
to create page tables that allow the host to find the memory.
Those page tables just used regular system memory. Unfortunately
in TTM those BO's are not allowed to be busy thus can't be
fenced and we have to fence those bo's because we don't want
to destroy the page tables while the host is still executing
the command buffers which might be accessing them.
To solve it we introduce a new placement VMW_PL_SYSTEM which
is very similar to TTM_PL_SYSTEM except that it allows
fencing. This fixes kernel oops'es during unloading of the driver
(and pci hot remove/add) which were caused by busy BO's in
TTM_PL_SYSTEM being present in the delayed deletion list in
TTM (TTM_PL_SYSTEM manager is destroyed before the delayed
deletions are executed)
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211105193845.258816-5-zackr@vmware.com
Some of our hosts have a bug where rescaning a pci bus results in stale
fifo memory being mapped on the host. This makes any fifo communication
impossible resulting in various kernel crashes.
Instead of unexpectedly crashing, predictably fail to load the driver
which will preserve the system.
Fixes: fb1d9738ca ("drm/vmwgfx: Add DRM driver for VMware Virtual GPU")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211105193845.258816-4-zackr@vmware.com
