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Kernel shadow >> + # stacks are FRED-only. >> + depends on !XEN_PV > Xen PV guests will not see FRET or CET_SS/CET_IBT in CPUID, because the > features as a whole are incompatible with a kernel running in Ring3. > > This is not a restriction/dependency that Linux should be putting in place. > > ~Andrew P.S.  They won't see FRED either...