> From: Matt Evans <[email protected]> > Sent: Wednesday, May 27, 2026 6:23 PM > > The P2PDMA code currently provides two features under the same > CONFIG_PCI_P2PDMA option: > > 1. Locate providers via pcim_p2pdma_provider() > 2. Manage actual P2P DMA > > Other code (such as vfio-pci) depends on 1, without having a hard > dependency on 2. > > A future commit expands the use of DMABUF in vfio-pci for non-P2P > scenarios, relying on pcim_p2pdma_provider() always being present. If > that depended on CONFIG_PCI_P2PDMA, it would make vfio-pci only > available if CONFIG_ZONE_DEVICE is present (e.g. 64-bit systems), even > when P2P is not needed. > > To resolve this, introduce CONFIG_PCI_P2PDMA_CORE which contains the > basic provider functionality to make it available even if the > CONFIG_PCI_P2PDMA feature is disabled or unavailable due to > !CONFIG_ZONE_DEVICE. Users such as vfio-pci can enable their own P2P > features based off the original CONFIG_PCI_P2PDMA (available when > CONFIG_ZONE_DEVICE is set). > > Signed-off-by: Matt Evans <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
