drm/i915/gvt: Drop unused helper intel_vgpu_reset_gtt()

Drop intel_vgpu_reset_gtt() as it no longer has any callers.  In addition
to eliminating dead code, this eliminates the last possible scenario where
__kvmgt_protect_table_find() can be reached without holding vgpu_lock.
Requiring vgpu_lock to be held when calling __kvmgt_protect_table_find()
will allow a protecting the gfn hash with vgpu_lock without too much fuss.

No functional change intended.

Fixes: ba25d977 ("drm/i915/gvt: Do not destroy ppgtt_mm during vGPU D3->D0.")
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-11-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

drivers/gpu/drm/i915/gvt/gtt.c

@@ -2817,24 +2817,6 @@ void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu, bool invalidate_old)
 	ggtt_invalidate(gvt->gt);
 }
 
-/**
- * intel_vgpu_reset_gtt - reset the all GTT related status
- * @vgpu: a vGPU
- *
- * This function is called from vfio core to reset reset all
- * GTT related status, including GGTT, PPGTT, scratch page.
- *
- */
-void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu)
-{
-	/* Shadow pages are only created when there is no page
-	 * table tracking data, so remove page tracking data after
-	 * removing the shadow pages.
-	 */
-	intel_vgpu_destroy_all_ppgtt_mm(vgpu);
-	intel_vgpu_reset_ggtt(vgpu, true);
-}
-
 /**
  * intel_gvt_restore_ggtt - restore all vGPU's ggtt entries
  * @gvt: intel gvt device

drivers/gpu/drm/i915/gvt/gtt.h

@@ -224,7 +224,6 @@ void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu, bool invalidate_old);
 void intel_vgpu_invalidate_ppgtt(struct intel_vgpu *vgpu);
 
 int intel_gvt_init_gtt(struct intel_gvt *gvt);
-void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu);
 void intel_gvt_clean_gtt(struct intel_gvt *gvt);
 
 struct intel_vgpu_mm *intel_gvt_find_ppgtt_mm(struct intel_vgpu *vgpu,