On Tue, Feb 10, 2026 at 07:06:20PM +0100, Marek Marczykowski-Górecki wrote: > Hi, > > Recently I started testing compatibility with Intel Lunar Lake. This is > the first one that uses "xe" instead of "i915" Linux driver for iGPU. > I test it with Qubes OS 4.3, which uses Xen 4.19.4 and PV dom0 running > Linux 6.17.9 in this test. > The result is rather sad: > https://openqa.qubes-os.org/tests/166691#step/simple_gui_apps/30 > or > https://openqa.qubes-os.org/tests/166700#step/desktop_linux_manager_config/42 > > The black windows are mapped from a domU (using grant tables). But if > you watch the video (in the "logs&assets" tab), login window of dom0 is > affected too (background is rendered significantly later than its text > and widgets). > > I didn't found any relevant errors in kernel (or Xen) messages. Just in > case, full dumps: > https://openqa.qubes-os.org/tests/166700/file/desktop_linux_manager_config-journalctl.log > https://openqa.qubes-os.org/tests/166700/file/desktop_linux_manager_config-xl-dmesg.log > > Some user reported similar issue with Intel Arc Pro B50, which also uses > "xe" driver: > https://github.com/QubesOS/qubes-issues/issues/10661 > > I tested also Linux 6.19-rc8, no improvements. > > My previous tests of the xe driver on older systems (Meteor Lake, Raptor > Lake) resulted in similar behavior, while i915 works fine there. But there > I needed to use force_probe parameter, and blamed the issue on xe not > officially supporting those platforms. I wanted to compare with i915 on > LNL, but i915 doesn't support that model at all (and if I force it, I > get kernel panic in i915_pci_probe...). > > Interestingly, it appears to work just fine on Qubes OS 4.2 (Xen 4.17.6, > same Linux dom0 version). I did not tested with Xen 4.21. > > In both cases, our Xen has the patch to use Linux's PAT layout applied. > That's a workaround for > https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/7648, which is > fixed now, but apparently similar bug is still present in a few other > drivers (including binary nvidia one...). > > The same Linux kernel started without Xen works just fine. > > Any ideas? > > Having good and a bad version, I can try to bisect this one, but given > it requires rebuilding Xen toolstack each time too (due to bisection > across releases), I'd rather avoid it if possible... > > I'm CC-ing also intel-xe list, maybe somebody there have some ideas how > to debug this.
Unfortunately I'm afraid we don't have any good advice here. First I thought about trying to isolate Mesa version in the Qubes OS version, but the fact that it works in bare metal makes this a silly option. It looks more a cache management indeed, and I'm afraid we will only find the definite spot after the bisect :( > > -- > Best Regards, > Marek Marczykowski-Górecki > Invisible Things Lab
