[PATCH 08/10] vfio/pci: Enable peer-to-peer DMA transactions by default
From: Leon Romanovsky <leon@kernel.org>
Date: 2025-07-23 13:02:24
Also in:
dri-devel, kvm, linux-iommu, linux-media, linux-mm, linux-pci, lkml
Subsystem:
the rest, vfio driver · Maintainers:
Linus Torvalds, Alex Williamson
From: Leon Romanovsky <leonro@nvidia.com> Make sure that all VFIO PCI devices have peer-to-peer capabilities enables, so we would be able to export their MMIO memory through DMABUF, Signed-off-by: Leon Romanovsky <leonro@nvidia.com> --- drivers/vfio/pci/vfio_pci_core.c | 4 ++++ include/linux/vfio_pci_core.h | 1 + 2 files changed, 5 insertions(+)
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 6328c3a05bcdd..1e675daab5753 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c@@ -29,6 +29,7 @@ #include <linux/nospec.h> #include <linux/sched/mm.h> #include <linux/iommufd.h> +#include <linux/pci-p2pdma.h> #if IS_ENABLED(CONFIG_EEH) #include <asm/eeh.h> #endif
@@ -2091,6 +2092,9 @@ int vfio_pci_core_init_dev(struct vfio_device *core_vdev) INIT_LIST_HEAD(&vdev->dummy_resources_list); INIT_LIST_HEAD(&vdev->ioeventfds_list); INIT_LIST_HEAD(&vdev->sriov_pfs_item); + vdev->provider = pci_p2pdma_enable(vdev->pdev); + if (IS_ERR(vdev->provider)) + return PTR_ERR(vdev->provider); init_rwsem(&vdev->memory_lock); xa_init(&vdev->ctx);
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index fbb472dd99b36..b017fae251811 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h@@ -94,6 +94,7 @@ struct vfio_pci_core_device { struct vfio_pci_core_device *sriov_pf_core_dev; struct notifier_block nb; struct rw_semaphore memory_lock; + struct p2pdma_provider *provider; }; /* Will be exported for vfio pci drivers usage */
--
2.50.1