| Date | Tue, 27 Sep 2022 14:03:59 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 22/23] x86/hreset: Configure history reset |
| |
On Fri, Sep 09, 2022 at 04:12:04PM -0700, Ricardo Neri wrote:
> +static u32 hardware_history_features __read_mostly;
__ro_after_init ?
> +static __always_inline void setup_hreset(struct cpuinfo_x86 *c) > +{ > + if (!cpu_feature_enabled(X86_FEATURE_HRESET)) > + return; > + > + /* > + * Use on all CPUs the hardware history features that the boot > + * CPU supports. > + */ > + if (c == &boot_cpu_data) > + hardware_history_features = cpuid_ebx(0x20); > + > + if (!hardware_history_features) > + return; > + > + wrmsrl(MSR_IA32_HW_HRESET_ENABLE, hardware_history_features); > + > + pr_info_once("x86/cpu: Intel History Reset (HRESET) activated\n"); > +} > + > /* These bits should not change their value after CPU init is finished. */ > static const unsigned long cr4_pinned_mask = > X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP |
|