On Wed, Jul 01, 2026 at 11:19:25AM +0530, Aneesh Kumar K.V (Arm) wrote:

Check the return value when converting swiotlb pools between encrypted and
decrypted mappings. If the default pool cannot be decrypted after early
initialization, mark the pool fully used so it cannot satisfy future bounce
allocations.

For late initialization, return the `set_memory_decrypted()` failure. For
restricted DMA pools, fail device initialization if the reserved pool
cannot be decrypted.

This prevents swiotlb from using pools whose encryption attributes do not
match their metadata, and avoids returning pages with uncertain encryption
state back to the allocator.

Tested-by: Michael Kelley <redacted>
Tested-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Petr Tesarik <redacted>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++---------
 1 file changed, 65 insertions(+), 15 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason