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Date: Mon, 20 Jul 2026 16:17:28 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>, Andy Lutomirski
 <luto@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Thomas Gleixner
 <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov
 <bp@alien8.de>, x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
 "Mike Rapoport (Microsoft)" <rppt@kernel.org>, Jason Gunthorpe
 <jgg@ziepe.ca>, Lu Baolu <baolu.lu@linux.intel.com>, David Hildenbrand
 <david@kernel.org>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Kiryl
 Shutsemau <kas@kernel.org>, iommu@lists.linux.dev, Kevin Tian
 <kevin.tian@intel.com>, stable@vger.kernel.org
Subject: Re: [PATCH] x86/mm/pat: allocate split page tables as kernel page
 tables
Message-Id: <20260720161728.1e5e5d848bcb53bc8757ede5@linux-foundation.org>
In-Reply-To: <20260720-fix-cpa-kernel-pagetables-v1-1-0766e782cefe@kernel.org>
References: <20260720-fix-cpa-kernel-pagetables-v1-1-0766e782cefe@kernel.org>
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On Mon, 20 Jul 2026 10:27:29 +0100 "Lorenzo Stoakes (ARM)" <ljs@kernel.org> wrote:

> When splitting a large page in CPA in __split_large_page() we allocate a
> PTE directly without going through the standard page table allocation
> routines such as pte_alloc_one_kernel().
> 
> This means the page table constructor is never called nor is the page table
> marked as a kernel page table.

Thanks, I'll await x86 review on this (Dave?).  Also, Sashiko might
have found a pre-existing thing:

	https://sashiko.dev/#/patchset/20260720-fix-cpa-kernel-pagetables-v1-1-0766e782cefe@kernel.org