Re: [Qemu-ppc] [PATCH v3 3/5] xics: setup cpu at realize time

[David Gibson]

On Thu, Jun 08, 2017 at 10:45:30AM +0200, Greg Kurz wrote:
> On Thu, 8 Jun 2017 12:01:12 +1000
> David Gibson <address@hidden> wrote:
> 
> > On Wed, Jun 07, 2017 at 07:17:09PM +0200, Greg Kurz wrote:
> > > Until recently, spapr used to allocate ICPState objects for the lifetime
> > > of the machine. They would only be associated to vCPUs in xics_cpu_setup()
> > > when plugging a CPU core.
> > > 
> > > Now that ICPState objects have the same lifecycle as vCPUs, it is
> > > possible to associate them during realization.
> > > 
> > > This patch hence open-codes xics_cpu_setup() in icp_realize(). The vCPU
> > > is passed as a property. Note that vCPU now needs to be realized first
> > > for the IRQs to be allocated. It also needs to resetted before ICPState
> > > realization in order to synchronize with KVM.  
> > 
> > Ok, what enforces those ordering constraints?
> > 
> 
> I'm not sure about what you're asking... I had to re-order because
> xics_cpu_setup() used to be called after the vCPU is realized and
> put in PAPR mode.

Duh, sorry, I wasn't thinking to ask about realize order, since that's
manual and you've re-ordered it to be correct.

You also mention that reset order matters, and I'm less clear on what
guarantees that the reset handlers for the components get called in
the right order.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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