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Subject: Re: kernel bug in "Drop WIMG in favour of new constants"?
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, "Darrick J. Wong"
 <darrick.wong@oracle.com>, Michael Ellerman <mpe@ellerman.id.au>
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Date: Fri, 17 Jun 2016 08:30:36 +1000
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On Thu, 2016-06-16 at 20:01 +0530, Aneesh Kumar K.V wrote:
> The pHyp part of the comment was added by you in 
> 3c726f8dee6f55e96475574e9f645327e461884c ([PATCH] ppc64: support 64k
> page) really an old commit. I also remember we having the discussion and
> concluding that it should be safe to assume that we can always enable
> memory coherence. Should we do the below patch of get Qemu fixed up ?
> like below
> 
> -        if ((ptel & (HPTE64_R_W | HPTE64_R_I | HPTE64_R_M)) != HPTE64_R_I) {
> +        wimg_flags = (ptel & (HPTE64_R_W | HPTE64_R_I | HPTE64_R_M));
> +
> +        if (wimg_flags != HPTE64_R_I && wimg_flags != (HPTE64_R_I | HPTE64_R_M)) {
>              return H_PARAMETER;
>          }

Makes sense.

Cheers,
Ben.