Re: [PATCH v7 13/22] dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED
Jason Gunthorpe <[email protected]>
| Newsgroups | dev.linux.lists.linux-coco,dev.linux.lists.iommu,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-s390,org.ozlabs.lists.linuxppc-dev |
|---|---|
| Message-ID | <[email protected]> |
On Wed, Jul 01, 2026 at 11:19:17AM +0530, Aneesh Kumar K.V (Arm) wrote:
> Teach swiotlb to distinguish between encrypted and decrypted bounce
> buffer pools, and make allocation and mapping paths select a pool whose
> state matches the requested DMA attributes.
>
> Add a cc_shared flag to io_tlb_mem, initialize it for the default and
> restricted pools, and propagate __DMA_ATTR_ALLOC_CC_SHARED into swiotlb
> pool allocation. Reject swiotlb alloc/map requests when the selected pool
> does not match the required encrypted/decrypted state.
>
> Also return DMA addresses with the matching phys_to_dma_{encrypted,
> unencrypted} helper so the DMA address encoding stays consistent with the
> chosen pool.
>
> Tested-by: Jiri Pirko <[email protected]>
> Tested-by: Michael Kelley <[email protected]>
> Tested-by: Mostafa Saleh <[email protected]>
> Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]>
> ---
> include/linux/dma-direct.h | 10 +++
> include/linux/swiotlb.h | 10 ++-
> kernel/dma/direct.c | 13 ++-
> kernel/dma/swiotlb.c | 177 ++++++++++++++++++++++++++++---------
> 4 files changed, 162 insertions(+), 48 deletions(-)
Reviewed-by: Jason Gunthorpe <[email protected]>
Jason