Re: [PATCH v8 3/7] crypto/ccp: Disable CPU hotplug while SNP is active

[Dave Hansen]

On 6/15/26 12:49, Ashish Kalra wrote:
> +	/*
> +	 * Disable CPU hotplug while SNP is active.  Guard against stacking
> +	 * the disable count: the legacy SNP_SHUTDOWN_EX path clears
> +	 * snp_initialized without re-enabling hotplug, so this can run
> +	 * again while hotplug is already disabled.
> +	 */
> +	if (!snp_cpu_hotplug_disabled) {
> +		cpu_hotplug_disable();
> +		snp_cpu_hotplug_disabled = true;
> +	}

This seems like a hack, guys.

cpu_hotplug_disable() seems like more of a temporary lock than enforcing
basically permanent system state.

This seems like it would be better implemented by registering a CPU
hotplug callback and then refusing to offline if sev->snp_initialized is
set.

snp_setup_rmpopt() can be run any time, right? It doesn't need to be
after sev->snp_initialized=1.