The patch titled
Subject: mm: re-allow pinning of zero pfns (again)
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-re-allow-pinning-of-zero-pfns-again.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-re-allow-pinning-of-zero-pfns-again.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Alex Williamson <alex.williamson@xxxxxxxxxx>
Subject: mm: re-allow pinning of zero pfns (again)
Date: Mon, 08 Aug 2022 22:42:24 -0600
The below referenced commit makes the same error as 1c563432588d ("mm: fix
is_pinnable_page against a cma page"), re-interpreting the logic to
exclude pinning of the zero page, which breaks device assignment with
vfio.
Link: https://lore.kernel.org/all/165490039431.944052.12458624139225785964.stgit@omen
Link: https://lkml.kernel.org/r/166002010021.381133.11357879752637949308.stgit@omen
Fixes: f25cbb7a95a2 ("mm: add zone device coherent type memory support")
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Alex Sierra <alex.sierra@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Felix Kuehling <felix.kuehling@xxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/include/linux/mm.h~mm-re-allow-pinning-of-zero-pfns-again
+++ a/include/linux/mm.h
@@ -1544,9 +1544,8 @@ static inline bool is_longterm_pinnable_
if (mt == MIGRATE_CMA || mt == MIGRATE_ISOLATE)
return false;
#endif
- return !(is_device_coherent_page(page) ||
- is_zone_movable_page(page) ||
- is_zero_pfn(page_to_pfn(page)));
+ return !(is_device_coherent_page(page) || is_zone_movable_page(page)) ||
+ is_zero_pfn(page_to_pfn(page));
}
#else
static inline bool is_longterm_pinnable_page(struct page *page)
_
Patches currently in -mm which might be from alex.williamson@xxxxxxxxxx are
mm-re-allow-pinning-of-zero-pfns-again.patch
