On Thu, Jan 11, 2018 at 05:58:11PM -0800, Dave Hansen wrote: > On 01/11/2018 05:32 PM, Ashok Raj wrote: > > +static void save_guest_spec_ctrl(struct vcpu_vmx *vmx) > > +{ > > + if (boot_cpu_has(X86_FEATURE_SPEC_CTRL)) { > > + vmx->spec_ctrl = spec_ctrl_get(); > > + spec_ctrl_restriction_on(); > > + } else > > + rmb(); > > +} > > Does this need to be "ifence()"? Better yet, do we just need to create > a helper for boot_cpu_has(X86_FEATURE_SPEC_CTRL) that does the barrier?
static_cpu_has() + hard asm-goto requirement. Please drop all the above nonsense on the floor hard. Let backporters sort out whever they need, don't introduce crap like that upstream.