Nvidia driver doesn’t work in Xen dom0 due to differing PAT

[DemiMarie]

I’m a developer of @QubesOS. In QubesOS/qubes-issues#9501, a Qubes OS user reported that the Nvidia driver doesn’t work in a Qubes OS dom0. This was found to be due to Xen using a different PAT than Linux normally does. Patching Xen to use Linux’s PAT hid the problem and allowed the driver to work normally.

Although a workaround has been found, using Linux’s PAT is not a supported configuration in Xen upstream. Qubes OS must carry it as an out of tree patch for this, which isn’t great. It would be nice to know if this is a bug in the Nvidia driver or a bug somewhere else in Linux.