Re: [PATCH v3 1/3] dma: Fix encryption bit clearing for dma_to_phys

[Gavin Shan]

On 2/28/25 12:41 AM, Suzuki K Poulose wrote:
> phys_to_dma() sets the encryption bit on the translated DMA address. But
> dma_to_phys() clears the encryption bit after it has been translated back
> to the physical address, which could fail if the device uses DMA ranges.
>
> AMD SME doesn't use the DMA ranges and thus this is harmless. But as we
> are about to add support for other architectures, let us fix this.
>
> Reported-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxx>
> Link: https://lkml.kernel.org/r/yq5amsen9stc.fsf@xxxxxxxxxx
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Steven Price <steven.price@xxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
> Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> ---
>   include/linux/dma-direct.h | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>