diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h b/drivers/gpu/drm/i915/i915_pvinfo.h
index e61144d45a94..c0cb2974caac 100644
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -104,7 +104,7 @@ struct vgt_if {
 } __packed;
 
 #define vgtif_reg(x) \
-	_MMIO((VGT_PVINFO_PAGE + (long)&((struct vgt_if *)NULL)->x))
+	_MMIO((VGT_PVINFO_PAGE + offsetof(struct vgt_if, x)))
 
 /* vGPU display status to be used by the host side */
 #define VGT_DRV_DISPLAY_NOT_READY 0