On Sat, Jun 02, 2018 at 10:23:20PM -0700, Dan Williams wrote: > +static inline int set_mce_nospec(unsigned long pfn) > +{ > + int rc; > + > + rc = set_memory_uc((unsigned long) __va(PFN_PHYS(pfn)), 1); You should really do the decoy_addr thing here that I had in mce_unmap_kpfn(). Putting the virtual address of the page you mustn't accidentally prefetch from into a register is a pretty good way to make sure that the processor does do a prefetch. -Tony