Re: [PATCH v15 05/23] x86/cpu/intel: Detect SGX support and update caps appropriately

[Jarkko Sakkinen]

 On Sat, Nov 03, 2018 at 03:05:39PM +0200, Andy Shevchenko wrote:
> > +static void detect_sgx(struct cpuinfo_x86 *c)
> > +{
> > +       bool unsupported = false;
> > +       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");
> > +               unsupported = true;
> > +       } else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
> > +               pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
> > +               unsupported = true;
> > +       } else if (!cpu_has(c, X86_FEATURE_SGX1)) {
> > +               pr_err_once("sgx: SGX1 instruction set not supported\n");
> > +               unsupported = true;
> > +       }
> 
> If you do
> 
> } else {
>  /* Supported */
>  return;
> }

Agree. Would this be a more clean flow in the attached patch?

/Jarkko