Re: [PATCH v17 06/23] x86/cpu/intel: Detect SGX support and update caps appropriately

From: Jarkko Sakkinen
Date: Sun Nov 18 2018 - 03:37:51 EST


On Fri, Nov 16, 2018 at 03:32:36PM -0800, Dave Hansen wrote:
> On 11/15/18 5:01 PM, Jarkko Sakkinen wrote:
> > +static void detect_sgx(struct cpuinfo_x86 *c)
> > +{
> > + unsigned long long fc;
> > +
> > + rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
> > + if (!(fc & FEATURE_CONTROL_LOCKED)) {
> > + pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
> > + goto out_unsupported;
> > + }
>
> This needs a check against the config option somewhere so the compiler
> can toss it in its entirety if SGX is config'd out.

Certainly. I'll flag it in the next version.

/Jarkko