Re: [for-5.0 4/4] spapr: Correct clamping of RMA to Node 0 size

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

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On Tue, Dec 03, 2019 at 03:18:37PM +1100, Alexey Kardashevskiy wrote:
> 
> 
> On 29/11/2019 12:35, David Gibson wrote:
> > The Real Mode Area (RMA) needs to fit within Node 0 in NUMA configurations.
> > We use a helper function spapr_node0_size() to calculate this.
> > 
> > But that function doesn't actually get the size of Node 0, it gets the
> > minimum size of all nodes, ever since b082d65a300 "spapr: Add a helper for
> > node0_size calculation".  That was added, apparently, because Node 0 in
> > qemu's terms might not have corresponded to Node 0 in PAPR terms (i.e. the
> > node with memory at address 0).
> 
> 
> After looking at this closely, I think the idea was that the first
> node(s) may have only CPUs but not memory, in this case
> node#0.node_mem==0 and things crash:

Ah!  Excellent point - I misread what the existing node0_size()
function was doing.  Corrected for the next spin.

-- 
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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