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Date:   Wed, 2 Feb 2022 06:04:17 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     John Hubbard <jhubbard@nvidia.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Peter Xu <peterx@redhat.com>, Jason Gunthorpe <jgg@ziepe.ca>,
        Jan Kara <jack@suse.cz>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>, linux-mm@kvack.org
Subject: Re: [PATCH 1/4] mm: Fix invalid page pointer returned with FOLL_PIN
 gups
Message-ID: <YfqPYbxGKoeHNhGv@infradead.org>
References: <20220131051752.447699-1-jhubbard@nvidia.com>
 <20220131051752.447699-2-jhubbard@nvidia.com>
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On Sun, Jan 30, 2022 at 09:17:49PM -0800, John Hubbard wrote:
> From: Peter Xu <peterx@redhat.com>
> 
> Alex reported invalid page pointer returned with pin_user_pages_remote() from
> vfio after upstream commit 4b6c33b32296 ("vfio/type1: Prepare for batched
> pinning with struct vfio_batch").  This problem breaks NVIDIA vfio mdev.

I haven't actually seen any nvidia mdev module in the tree.