Can't speak for Arch but I followed this guide on Debian: https://youtu.be/dsDUtzMkxFk
With mainline kernel (4.11.6 at the time: http://kernel.org ) With this ACS patch: https://aur.archlinux.org/cgit/aur.git/tree/add-acs-overrides.patch?h=linux-vfio (From linux-vfio from the AUR).
Hardware:
- R7 1700
- Asus Prime X370 Pro
- GTX 1050ti (Primary)
- GT 710 (Passed through)
Worked fine with Windows 10