[PATCH v2 07/10] vfio/pci: Add dma-buf export config for MMIO regions

Leon Romanovsky
2025-09-11T11:34:09Z

From: Leon Romanovsky <leonro@nvidia.com>

Add new kernel config which indicates support for dma-buf export
of MMIO regions, which implementation is provided in next patches.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/vfio/pci/Kconfig | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index 2b0172f546652..55ae888bf26ae 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -55,6 +55,26 @@ config VFIO_PCI_ZDEV_KVM

To enable s390x KVM vfio-pci extensions, say Y.

+config VFIO_PCI_DMABUF
+ bool "VFIO PCI extensions for DMA-BUF"
+ depends on VFIO_PCI_CORE
+ depends on PCI_P2PDMA && DMA_SHARED_BUFFER
+ default y
+ help
+ Enable support for VFIO PCI extensions that allow exporting
+ device MMIO regions as DMA-BUFs for peer devices to access via
+ peer-to-peer (P2P) DMA.
+
+ This feature enables a VFIO-managed PCI device to export a portion
+ of its MMIO BAR as a DMA-BUF file descriptor, which can be passed
+ to other userspace drivers or kernel subsystems capable of
+ initiating DMA to that region.
+
+ Say Y here if you want to enable VFIO DMABUF-based MMIO export
+ support for peer-to-peer DMA use cases.
+
+ If unsure, say N.
+
source "drivers/vfio/pci/mlx5/Kconfig"

source "drivers/vfio/pci/hisilicon/Kconfig"
--
2.51.0