Re: [PATCH v3 1/4] mm: Fix invalid page pointer returned with FOLL_PIN gups

From: John Hubbard
Date: Thu Feb 03 2022 - 16:13:58 EST


On 2/3/22 06:00, Christoph Hellwig wrote:
On Thu, Feb 03, 2022 at 01:32:29AM -0800, John Hubbard wrote:
From: Peter Xu <peterx@xxxxxxxxxx>

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.

There still isn't any nvidia vfio mdev driver in the tree, so this
changelog stilldoesn't make sense.

I'll remove that last sentence (and put in a tiny note that I'm scribbling
on Peter's commit description a little bit more), in order to avoid any
references to out of tree things.

thanks,
--
John Hubbard
NVIDIA