Re: [PATCH v4 04/13] dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED

[Jason Gunthorpe]

On Tue, May 19, 2026 at 02:27:54PM +0000, Mostafa Saleh wrote:
> However, as I mentioned to Jason, I think with some tweaks to
> force_dma_unencrypted() we can make it work under pKVM for aligned
> memory which eliminates some of the bouncing.
> I am currently investigating that.

force_dma_unencrypted() literally means that memory passed into the
DMA API *without* DMA_ATTR_CC_SHARED cannot be DMA'd from.

It should not mean anything else. The DMA API should never decrypt
passed in memory. You always have to bounce.

Jason