[Linaro-mm-sig] Sharing dma-bufs using a driver-private interconnect

Hi!

I previously discussed this with Simona on IRC but would like to get some feedback also from a wider audience:

We're planning to share dma-bufs using a fast interconnect in a way similar to pcie-p2p:

The rough plan is to identify dma-bufs capable of sharing this way by looking at the address of either the dma-buf ops and / or the importer_ops to conclude it's a device using the same driver (or possibly child driver) and then take special action when the dma- addresses are obtained. Nothing visible outside of the xe driver or its child driver.

Are there any absolute "DON'T"s or recommendations to keep in mind WRT to this approach?

Thanks, Thomas