Re: [PATCH v4 5/8] L1TFv4 8

[Thomas Gleixner <tglx@linutronix.de>]

> +ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> +	if (!boot_cpu_has_bug(X86_BUG_L1TF))
> +		return sprintf(buf, "Not affected\n");
> +
> +	if (boot_cpu_has(X86_FEATURE_L1TF_WA))
> +		return sprintf(buf, "Mitigated\n");
> +
> +	return sprintf(buf, "Mitigation Unavailable\n");

That's 'Vulnerable' for all other issues, so please make it consistent.

> +static bool __init l1tf_wa_possible(void)
> +{
> +#if CONFIG_PGTABLE_LEVELS == 2
> +	pr_warn("Kernel not compiled for PAE. No workaround for L1TF\n");
> +	return false;
> +#endif
> +	return true;
> +}
> +
>  /*
>   * Do minimum CPU detection early.
>   * Fields really needed: vendor, cpuid_level, family, model, mask,
> @@ -989,8 +998,12 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
>  	setup_force_cpu_cap(X86_FEATURE_ALWAYS);
>  
>  	if (!x86_match_cpu(cpu_no_speculation)) {
> -		if (cpu_vulnerable_to_meltdown(c))
> +		if (cpu_vulnerable_to_meltdown(c)) {
>  			setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
> +			setup_force_cpu_bug(X86_BUG_L1TF);
> +			if (l1tf_wa_possible())
> +				setup_force_cpu_cap(X86_FEATURE_L1TF_WA);

That extra indirection is pointless. 

static void __init l1tf_init_workaround(void)
{
#if CONFIG_PGTABLE_LEVELS == 2
	pr_warn("Kernel not compiled for PAE. No workaround for L1TF\n");
#else
	setup_force_cpu_cap(X86_FEATURE_L1TF_WA);
#endif
}

Hmm?

> +ssize_t __weak cpu_show_l1tf(struct device *dev,
> +				   struct device_attribute *attr, char *buf)

Please align the arguments in the second row in the same way as all other
weak functions do. 

Thanks,

	tglx