Here is How to Root your Pixel XL on Android Oreo
If you have tried rooting your Pixel XL device after updating to Android Oreo, you may have noticed that your typical rooting methods don’t really work well on Android’s newest version. If that’s the case, then we’ve got you covered. XDA Senior Member GroovinChip has put together a step-by-step guide that walks us through how to get root access back on the Google Pixel XL running Android 8.0. The new method involves flashing Chainfire’s SuHide in conjunction with SuperSU and AROMA SuperSU Config to get systemless root access on the Google Pixel. For more details and step-by-step instructions, check out the main thread by following the link below.
Check out the Pixel XL rooting guide