On 13/01/2018 11:16, Longpeng (Mike) wrote: >> + /* >> + * FIXME: this is only needed until SPEC_CTRL is supported >> + * by upstream Linux in cpufeatures, then it can be replaced >> + * with static_cpu_has. >> + */ >> + have_spec_ctrl = cpu_has_spec_ctrl(); >> + if (have_spec_ctrl) >> + pr_info("kvm: SPEC_CTRL available\n"); >> + else >> + pr_info("kvm: SPEC_CTRL not available\n"); >> + > > In this approach, we must reload these modules if we update the microcode later ? I strongly suggest using early microcode update anyway. Paolo