[PATCH 08/10] vfio/pci: Enable peer-to-peer DMA transactions by default

[Leon Romanovsky]

From: Leon Romanovsky <leonro at 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 at 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