To ensure the module exists, first load it. Then when we try to unload
the module (to check that our modprobe interface works), we will not get
spurious failures due to -ENOENT (in this case meaning the module did
not exist):

(vgem_basic:18361) igt-core-DEBUG: Starting subtest: unload
(vgem_basic:18361) igt-kmod-DEBUG: Could not remove module vgem (No such file or directory)
Test requirement not met in function test_unload, file vgem_basic.c:331:
Test requirement: module_unload() == 0
Last errno: 2, No such file or directory
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>

vgem is a nasty test case for various parts of the core as it is a
virtual device with drm_device.dev == NULL; this includes drm_setversion
for example.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

As we have libkmod available, it is faster and safer than calling
system().
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Since vgem doesn't have any callbacks from shmemfs to its, we don't need
to keep the module around to service a pagefault when only using the
shmemfs facilities. Adjust the test to try to unload and check the mmap
for access.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

We found a bug where a dmabuf did not keep the module alive (and so when
i915 tried to use it later, it exploded).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

To protect the kernel against unscrupulous fence users, fences should
automatically signal after a timeout.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

For fun, debugfs/.../names currently explodes, so lets capture that and
make sure that basic access to debugfs does no harm.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>