On Wed, 8 Feb 2017, Kyle Huey wrote: > rr (http://rr-project.org/), a userspace record-and-replay reverse- > execution debugger, would like to trap and emulate the CPUID instruction. > This would allow us to a) mask away certain hardware features that rr does > not support (e.g. RDRAND) and b) enable trace portability across machines > by providing constant results. > > Newer Intel CPUs (Ivy Bridge and later) can fault when CPUID is executed at > CPL > 0. Expose this capability to userspace as a new pair of arch_prctls, > ARCH_GET_CPUID and ARCH_SET_CPUID. > > Since v13: > All: rebased on top of tglx's __switch_to_xtra patches > (https://lkml.org/lkml/2016/12/15/432) That doesn't help because that patchset is stale and it has unresolved comments. I don't know when I have cycles to revisit it, but if you want to have a try feel free to do so. Thanks, tglx