Re: [PATCH v6 25/34] swiotlb: Add warnings for use of bounce buffers with SME

[Christoph Hellwig]

On Wed, Jun 07, 2017 at 02:17:32PM -0500, Tom Lendacky wrote:
> Add warnings to let the user know when bounce buffers are being used for
> DMA when SME is active.  Since the bounce buffers are not in encrypted
> memory, these notifications are to allow the user to determine some
> appropriate action - if necessary.

And what would the action be?  Do we need a boot or other option to
disallow this fallback for people who care deeply?