MSR_IA32_SPEC_CTRL
x86_msr_op(MSR_IA32_SPEC_CTRL, (for_all_cpus ?
x86_msr_op(MSR_IA32_SPEC_CTRL,
v = rdmsr(MSR_IA32_SPEC_CTRL);
wrmsr(MSR_IA32_SPEC_CTRL, v & ~(IA32_SPEC_CTRL_IBRS |
wrmsr(MSR_IA32_SPEC_CTRL, v);