There's a debian bugreport open - now against qemu - https://bugs.debian.org/988333 - which initially said VGA Intel IGD Passthrough to Debian Xen HVM DomUs not working but worked okay with windows DomUs.
The most interesting comment in there is the last one, https://bugs.debian.org/988333#146 , which sums it all up and provides a patch for the issue, at https://github.com/QubesOS/qubes-vmm-xen-stubdom-linux/pull/3/commits/ab2b4c2ad02827a73c52ba561e9a921cc4bb227c which is from 2017 (!). I wonder if we should apply this one upstream, or if it is somehow incorrect fix, should fix this particular issue the right way. It's 5 years old already and people are still suffering... :) Thanks, /mjt
