On Tue, Aug 04, 2026 at 10:19:11AM -0600, Logan Gunthorpe wrote:

There's a vague convention for this already: the term 'p2pmem' is often used for cases where the driver uses the allocator, etc. (I think I had this intention when I wrote the code and have since forgotten about it).

I've been calling it the genalloc layer and the core layer. p2pmem would be OK to refer to the genalloc stuff. So if you want to have CONFIG_PCI_P2PDMA and CONFIG_PCI_P2PMEM that seem sOk

code into it's own file, potentially renaming some functions. Then, in the end, we would probably have a pcim_p2pdma_supported() function and a pcim_p2pmem_supported() function, the latter being used by existing use cases.

Not quite sure why we need this?

Matt, the mlx5 stuff is the same as VFIO, it just uses the "core" layer and does not use the genalloc. So there shouldn't be an issue here, if the genalloc is off then the mlx5 stuff should still work. There shouldn't be a case where CONFIG_PCI_P2PDMA=y and mlx5 is broken?

Did some of APIs get mixed into the genalloc family that should not have?

Jason