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

Leon Romanovsky
2026-05-05T10:49:18Z

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