drm/i915: Disable semaphore on vGPU for now
authorZhenyu Wang <zhenyuw@linux.intel.com>
Wed, 27 Mar 2019 09:06:36 +0000 (17:06 +0800)
committerChris Wilson <chris@chris-wilson.co.uk>
Wed, 27 Mar 2019 15:13:28 +0000 (15:13 +0000)
commita2deb87396b0903d30ce73af6fc8fc82e9e32c62
tree1ee71b399d2772e12b2b27070d0b3ea1d6251129
parent5aa2c9ae9371326d9ee9199fe5dee072cc16c6a8
drm/i915: Disable semaphore on vGPU for now

This is to disable semaphore usage when on vGPU for now. Unfortunately
GVT-g hasn't fully enabled semaphore usage yet, so current guest with
semaphore use would cause vGPU failure.

Although current semaphore failure with vGPU can be simply resolved by
allowing cmd parser to accept MI_SEMAPHORE_WAIT command with address
audit, we're checking general usage of semaphore and how we should
handle it properly for virtualization in consider of function and
security concern. So we decide to request to disable it for now in
guest driver. Once GVT could support it, we would add new compat bit
to turn it on.

Fixes: e88619646971 ("drm/i915: Use HW semaphores for inter-engine synchronisation on gen8+") #vgpu
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190327090636.3547-1-zhenyuw@linux.intel.com
drivers/gpu/drm/i915/intel_lrc.c