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Date: Fri, 24 Aug 2018 14:19:07 -0700
From: Guenter Roeck <linux@roeck-us.net>
To: Roland Dreier <roland@purestorage.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Ben Hutchings <ben.hutchings@codethink.co.uk>,
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        linux-efi@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
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Subject: Re: [PATCH 4.4 103/105] Revert "x86/mm/pat: Ensure cpa->pfn only
 contains page frame numbers"
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+Andi Kleen <ak@linux.intel.com>

On Fri, Aug 24, 2018 at 01:04:09PM -0700, Roland Dreier wrote:
> > Ok, so what patch should be reverted?  I'm seeing other reports of
> > problems all around this same area, but I can't figure out exactly what
> > to do.
> 
> Are any of those reports public?  If so can you point me at them, I'm
> curious if the symptoms match up.
> 
> I don't think we want to revert anything.  I think you should pull in
> edc3b9129cec and at least the first three patches that Ben listed:
> 
> 21cdb6b56843 x86/mm: Page align the '_end' symbol to avoid pfn conversion bugs
> b61a76f8850d x86/efi: Map RAM into the identity page table for mixed mode
> 753b11ef8e92 x86/efi: Setup separate EFI page tables in kexec paths
> 
> the first patch takes a bit of massaging (mostly because some of it is
> already touched by 02ff2769edbc, which keeps the changes from
> edc3b9129cec, and so we can drop a good bit when applying).  The other
> three apply cleanly.
> 
> I'm currently testing that and can send you the state of my tree in a bit.
> 
>  - R.