Hi Thomas, On 5/16/25 10:33, Thomas Hellström wrote: > 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.
As far as I can see that should work and we have recommended doing exactly that to multiple people in the past. > Are there any absolute "DON'T"s or recommendations to keep in mind WRT > to this approach? My only requirement is that you write up some documentation (preferable either in drivers/dma-buf/dma-buf.c or Documentation/driver-api/dma-buf.rst) how drivers should do this, what the implications with the rest of the DMA-buf interface is etc... etc... The goal is to nail down how to do driver private interfaces without breaking interoperability with drivers who don't participate in that. Regards, Christian. > > Thanks, > Thomas > )
