[PATCH 0/2] mm/cma: accept memory of CMA areas reserved with memblock_reserve()

[Mike Rapoport (Microsoft)]

Pages of allocated CMA areas are released to the buddy allocator with
__free_pages(), which does not check for unaccepted memory.

This usually works because memblock accepts the memory it allocates.

However, multi-range CMA areas, used by hugetlb_cma, and fixed CMA areas
requested with cma=<size>@<base> are reserved with memblock_reserve() and
their memory is never accepted.

On TDX and SEV-SNP guests the first access to such a page is fatal.

To ease the backporting, each case is addressed by a separate patch:
- patch 1 accepts the memory of multi-range CMA areas
- patch 2 does the same for the fixed CMA areas

The second patch won't apply cleanly to 6.6 and 6.12, but I believe the
stable team LLMs will take care of that :)

---
Mike Rapoport (Microsoft) (2):
      mm/cma: accept memory of multi-range CMA areas
      mm/cma: accept memory of CMA areas reserved at a fixed address

 mm/cma.c | 4 ++++
 1 file changed, 4 insertions(+)
---
base-commit: 5b0764a53235d3c77e1ed674e836e1b3fe1a4b1f
change-id: 20261029-cma-multi-97fd4e58aa08

--
Sincerely yours,
Mike.