Re: [PATCH v4 03/11] x86/startup_64: Simplify CR4 handling in startup code

[Borislav Petkov]

On Tue, Feb 13, 2024 at 01:41:47PM +0100, Ard Biesheuvel wrote:
> -#ifdef CONFIG_X86_5LEVEL
> -	testb	$1, __pgtable_l5_enabled(%rip)
> -	jz	1f
> -	orl	$X86_CR4_LA57, %ecx
> -1:
> +	orl	$X86_CR4_MCE, %edx
>  #endif
> +	movq	%cr4, %rcx
> +	andl	%edx, %ecx

Let's just state it explicitly:

	/* Even if ignored in long mode, set PSE uniformly on all logical CPUs. */

> +	btsl	$X86_CR4_PSE_BIT, %ecx
>  	movq	%rcx, %cr4

-- 
Regards/Gruss,
    Boris.

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