Re: [PATCH v7 21/22] dma: swiotlb: handle set_memory_decrypted() failures

[Jason Gunthorpe]

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 <mhklinux@xxxxxxxxxxx>
> Tested-by: Mostafa Saleh <smostafa@xxxxxxxxxx>
> Reviewed-by: Petr Tesarik <ptesarik@xxxxxxxx>
> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@xxxxxxxxxx>
> ---
>  kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++---------
>  1 file changed, 65 insertions(+), 15 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Jason