Re: [PATCH v3 1/2] x86/sev: Do not initialize SNP if missing CPUs

[Borislav Petkov]

On Thu, Apr 09, 2026 at 01:56:01PM -0600, Tycho Andersen wrote:
> @@ -521,12 +522,20 @@ void snp_prepare(void)
>  	 */
>  	rdmsrq(MSR_AMD64_SYSCFG, val);
>  	if (val & MSR_AMD64_SYSCFG_SNP_EN)
> -		return;
> +		return 0;
>  
>  	clear_rmp();
>  
>  	cpus_read_lock();
>  
> +	if (!cpumask_equal(cpu_online_mask, cpu_present_mask)) {
> +		ret = -EOPNOTSUPP;
> +		pr_warn("Skipping SNP initialization. CPUs online %*pbl, present %*pbl\n",

You need to say why exactly you're aborting here:

			"SNP init failed: not all CPUs online: (%*pbl online <-> %*pbl present masks)."

or something along those lines.

-- 
Regards/Gruss,
    Boris.

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