Hello,
I think it is b968e84b509d ("x86/iopl: Fake iopl(3) CLI/STI usage")
which uncovered an issue with get_desc() trying to access the GDT, as
introduced by 670f928ba09b ("x86/insn-eval: Add utility function to
get segment descriptor"). When running in a PV domain under Xen, the
(hypervisor's) GDT isn't accessible; with UMIP enabled by Xen even
SGDT wouldn't work, as the kernel runs in ring 3.
There's currently no hypercall to retrieve a descriptor from the GDT.
It is instead assumed that kernels know where their present GDT
lives. Can the native_store_gdt() be replaced there, please?
For context (I don't think it should matter much here) I'm observing
this with the kernel put underneath a rather old distro, where
hwclock triggers this path.
Thanks, Jan
