[PATCH 38/44] KVM: Disable CPU hotplug during hardware enabling

Huang, Kai kai.huang at intel.com
Thu Nov 10 13:20:57 AEDT 2022


On Thu, 2022-11-10 at 01:08 +0000, Huang, Kai wrote:
> > -	WARN_ON(!irqs_disabled());
> > +	/*
> > +	 * Compatibility checks are done when loading KVM and when enabling
> > +	 * hardware, e.g. during CPU hotplug, to ensure all online CPUs are
> > +	 * compatible, i.e. KVM should never perform a compatibility check
> > on
> > +	 * an offline CPU.
> > +	 */
> > +	WARN_ON(!irqs_disabled() && cpu_active(cpu));
> 
> Comment doesn't match with the code?
> 
> "KVM should never perform a compatibility check on on offline CPU" should be
> something like:
> 
> 	WARN_ON(!cpu_online(cpu));
> 
> So, should the comment be something like below?
> 
> "KVM compatibility check happens before CPU is marked as active".

Also ignore this one as I only thought about hotplug case.


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