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Subject: Re: [PATCH v2 3/9] powerpc/powernv: Remove real mode access limit
 for early allocations
From: Benjamin Herrenschmidt <benh@au1.ibm.com>
Reply-To: benh@au1.ibm.com
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Michael Ellerman
 <mpe@ellerman.id.au>,
 Nicholas Piggin <npiggin@gmail.com>, linuxppc-dev@lists.ozlabs.org
Cc: Suraj Jitindar Singh <surajjs@ozlabs.au.ibm.com>, kvm-ppc@vger.kernel.org
Date: Tue, 12 Sep 2017 20:26:07 +1000
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On Tue, 2017-09-12 at 15:43 +0530, Aneesh Kumar K.V wrote:
> Yes. I added the limit to radix after I observed that we have MSR[SF] =
> 0.
> 
> IIRC it was PACA access that was causing it to crash on return from RTAS.
> 
> hmm the commit also explains that.
> 
> powerpc/mm/radix: Limit paca allocation in radix
> 
> On return from RTAS we access the paca variables and we have 64 bit
> disabled. This requires us to limit paca in 32 bit range.
> 
> Fix this by setting ppc64_rma_size to first_memblock_size/1G range.

That should be fixable with better use of temporaries...

Ben.