From: Jason Gunthorpe <jgg@nvidia.com>
To: Steven Sistare <steven.sistare@oracle.com>
Cc: Alex Williamson <alex.williamson@redhat.com>, iommu@lists.linux.dev
Subject: Re: mapping files for iommufd
Date: Tue, 13 Aug 2024 11:36:20 -0300 [thread overview]
Message-ID: <20240813143620.GW8378@nvidia.com> (raw)
In-Reply-To: <b48cba98-cf51-40dc-9f57-4c1a7c493f78@oracle.com>
On Tue, Aug 13, 2024 at 10:23:10AM -0400, Steven Sistare wrote:
> The correct explanation is my test succeeded for an older kernel, based on 5.15.
> It failed in 6.9. This change in 6.4 (which Jason quotes from above) appears to be
> the reason:
> 8ac2684 mm/gup: disallow FOLL_LONGTERM GUP-nonfast writing to file-backed mappings
>
> I do not question the need for that fix, but I am surprised that QEMU users have not
> complained about new kernels failing for hugetlbfs plus vfio. Maybe most are still
> on older stable kernels (as I was).
hugetlbfs is supposed to work
Normal filesystems are not
Jason
next prev parent reply other threads:[~2024-08-13 14:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-12 18:09 mapping files for iommufd Steven Sistare
2024-08-12 18:40 ` Jason Gunthorpe
2024-08-12 18:56 ` Steven Sistare
2024-08-12 21:05 ` Alex Williamson
2024-08-13 14:23 ` Steven Sistare
2024-08-13 14:36 ` Jason Gunthorpe [this message]
2024-08-13 15:13 ` Steven Sistare
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