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Date: Tue, 15 Aug 2017 22:10:54 +1000
From: Nicholas Piggin <npiggin@gmail.com>
To: Benjamin Herrenschmidt <benh@au1.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@lists.ozlabs.org,
 Suraj Jitindar Singh <surajjs@ozlabs.au.ibm.com>, kvm-ppc@vger.kernel.org,
 aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [PATCH v2 3/9] powerpc/powernv: Remove real mode access limit
 for early allocations
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On Mon, 14 Aug 2017 23:13:07 +1000
Benjamin Herrenschmidt <benh@au1.ibm.com> wrote:

> On Mon, 2017-08-14 at 22:49 +1000, Michael Ellerman wrote:
> > > -     /*
> > > -      * We limit the allocation that depend on ppc64_rma_size
> > > -      * to first_memblock_size. We also clamp it to 1GB to
> > > -      * avoid some funky things such as RTAS bugs.  
> > 
> > That comment about RTAS is 7 years old, and I'm pretty sure it was a
> > historical note when it was written.
> > 
> > I'm inclined to drop it and if we discover new bugs with RTAS on Power9
> > then we can always put it back.  
> 
> Arent' we using a 32-bit RTAS ? (Afaik there's a 64-bit one, we just
> never used it ..). In this case we need to at least clamp to 2G (no
> trust RTAS doing unsigned properly).

Is there any allocation not covered by RTAS_INSTANTIATE_MAX?

Thanks,
Nick