Hi, With the aforementioned commit I am no longer able to use PCI passthrough to a Windows guest on the X570 chipset with a 5950X CPU. The minimal reproducer for me is to attach a GPU to the VM and attempt to start Windows setup from an iso image. The VM will apparently livelock at the setup splash screen before the spinner appears as one of my CPU cores goes up to 100% usage until I force off the VM. This could be very machine-specific though. Reverting to the old XOR check fixes both 6.12.y stable and 6.13-rc2 for me. Otherwise they're both bad. Can you please look into it? I can share the config I used for test builds if it would help. Regards, Simon
