Re: [PATCH 2/4] arm64/fpsimd: Discover maximum vector length implemented by any CPU

[Mark Brown]

On Wed, Jun 05, 2024 at 01:13:20PM +0100, Marc Zyngier wrote:
> Mark Brown <broonie@xxxxxxxxxx> wrote:

> > +	/*
> > +	 * pKVM allocates and uses storage for host state based on the
> > +	 * largest per-PE VL, reject new PEs with a larger maximum.
> > +	 */
> > +	if (is_protected_kvm_enabled()) {
> > +		if (max_vl > info->max_cpu_vl) {
> > +			pr_warn("%s: cpu%d: would increase maximum VL\n",
> > +				info->name, smp_processor_id());
> > +			return -EINVAL;
> > +		}
> > +	}

> Once protected mode is enabled, no new CPU can be booted (see
> psci_relay.c::psci_cpu_on()).

Ah, that's a bit easier.  Might still be worth keeping the check just in
case that changes or we acquire some further use of this value but it's
not currently needed and the comment could be updated.

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