Re: [PATCH v4 2/7] xen/arm: SMP support

[Ian Campbell <Ian.Campbell@citrix.com>]

> > > @@ -216,6 +245,8 @@ static int __init xen_guest_init(void)
> > >  	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
> > >  	 * for secondary CPUs as they are brought up. */
> > >  	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
> > > +	for_each_online_cpu(i)
> > > +		xen_secondary_init(i);
> > >  
> > >  	gnttab_init();
> > >  	if (!xen_initial_domain())
> > [...]
> > > @@ -244,7 +280,7 @@ static int __init xen_init_events(void)
> > >  		return -EINVAL;
> > >  	}
> > >  
> > > -	enable_percpu_irq(xen_events_irq, 0);
> > > +	on_each_cpu(xen_percpu_enable_events, NULL, 0);
> > 
> > It feels like there ought to be some sort of per-cpu bringup callback
> > which takes care of these dynamically. Maybe that doesn't matter until
> > we get vcpu hotplug going?
> 
> I suspect there isn't one, considering that on_each_cpu is also used by 
> kvm_vgic_hyp_init, kvm_timer_hyp_init and others.

Could we use cpu_notifiers for this?