A preview build of B317 Android 6.0 Marshmallow is available for Huawei P8 (GRA-UL10) in Germany. You can download this firmware package using the official mirror provided below.
Download Huawei P8 B317 Marshmallow Firmware [Stable] [Europe]
Huawei P8 (GRA-L09) has officially getting the final B317 Android 6.0 Marshmallow update based on Emotion UI 4.0 in several European countries. You can download the full firmware package of this update below.