[Linaro-mm-sig] Re: [PATCH 4/9] vfio/pci: Convert BAR mmap() to use a DMABUF

On Mon, May 04, 2026 at 04:40:41AM -0300, Jason Gunthorpe wrote:

On Fri, May 01, 2026 at 04:19:15PM -0600, Alex Williamson wrote:

...

Exporting dma-bufs from vfio-pci is a feature, but mmap of MMIO BARs is a legacy requirement. That legacy requirement now depends on PCI_P2PDMA, which depends on 64BIT and ZONE_DEVICE.

That should be split up now, Leon missed it when he added the new APIs that didn't require ZONE_DEVICE..

Sorry, what did I miss here? VFIO_DMABUF is an optional feature and is enabled only when P2P support is available. It does not affect legacy systems where P2P cannot be enabled.

Thanks