Messages in this thread |  | | Date | Fri, 12 Jan 2018 10:51:48 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 3/5] x86/ibrs: Add direct access support for MSR_IA32_SPEC_CTRL |
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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.
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