On Sun, 31 Jan 2021, Tamas K Lengyel wrote: > This seems to have been caused by a monitor being attached to the HDMI > port, with HDMI unplugged dom0 boots OK.
FYI others have reported issues with swiotlb-xen when using graphics: https://marc.info/?l=xen-devel&m=161201486021603 Disabling swiotlb-xen makes it work for them.
