Re: [Qemu-devel] [PATCH for-2.10 1/8] ppc/xics: add a xics_get_cpu_index_by_pir() helper

[David Gibson <david@gibson.dropbear.id.au>]

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On Tue, Mar 14, 2017 at 06:00:43PM +0100, Cédric Le Goater wrote:
> On 03/14/2017 06:38 AM, David Gibson wrote:
> > On Wed, Mar 08, 2017 at 11:52:44AM +0100, Cédric Le Goater wrote:
> >> This helper will be used to translate the server number of the XIVE
> >> (which is a PIR) into an ICPState index number (which is a cpu index).
> >>
> >> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> > 
> > This seems a slightly roundabout way of doing things.  Why not just
> > have the vcpu_by_pir() interface, then have the XICSFabric implementor
> > go directly from PIR to xics server state.
> 
> So what you are saying is that we should try to move the "nature"
> of the 'server' parameter of the xics framework in the icp_get() 
> handler of the XICSFabric. Correct ? Because at the end, it all 
> boils down to use a 'server' to look for an ICPState.
> 
> Each machine would do its conversion : 
> 
> 	xics_get_cpu_index_by_dt_id() for spapr
> 	xics_get_cpu_index_by_pir() for powernv

Yes, that's exactly right.  I think it makes sense for the XICSFabric
to be the thing that defines the mapping from XICS server numbers to
whatever other ID is relevant.

-- 
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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