Re: [RFC PATCH 23/23] x86/process: Reset hardware history in context switch

From: Peter Zijlstra
Date: Tue Sep 27 2022 - 08:52:56 EST


On Fri, Sep 09, 2022 at 04:12:05PM -0700, Ricardo Neri wrote:

> +void reset_hardware_history(void)
> +{
> + if (!static_cpu_has(X86_FEATURE_HRESET))
> + return;
> +
> + asm volatile("mov %0, %%eax;" __ASM_HRESET "\n" : :
> + "r" (hardware_history_features) : "%rax");
> +}

asm_inline volatile (ALTERNATIVE("", __ASM_HRESET, X86_FEATURE_HRESET)
: : "a" (hardware_history_features) : "memory");