Re: [PATCH v4 RESEND 4/11] x86/asm: Fix pud/pmd interfaces to handle large PAT bit

From: Toshi Kani
Date: Mon Nov 09 2015 - 19:44:53 EST


On Mon, 2015-11-09 at 16:18 -0700, Toshi Kani wrote:
> On Mon, 2015-11-09 at 17:36 -0500, Boris Ostrovsky wrote:
> > On 11/09/2015 03:47 PM, Kirill A. Shutemov wrote:
> > > On Mon, Nov 09, 2015 at 02:39:31PM -0500, Boris Ostrovsky wrote:
> > > > On 11/09/2015 02:16 PM, Toshi Kani wrote:
:
> > > >
> > > > FWIW, it looks like pmd_pfn_mask() inline is causing this. Reverting it
> > > > alone makes this crash go away.
> > > Could you check the patch below?
> >
> >
> > I does fix the problem on baremetal, thanks. My 32-bit Xen guests still
> > fail which I thought was the same issue but now that I looked at it more
> > carefully it has different signature.
>
> I do not think Xen is hitting this, but I think page_level_mask() has the same
> issue for a long time. I will set up 32-bit env on a system with >4GB memory
> to verify this.

As Kirill explained me in his code review comment for *PAGE_MASK, page_level_mas
k() is fine as it is used for virtual addresses.

-Toshi
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