Update vfio_pci_core_mmap() & vfio_pci_core_feature_dma_buf() to enforce mutual exclusivity with ZONE_DEVICE P2P registration. If a BAR has been registered for native P2P (via VFIO_DEVICE_FEATURE_P2P_REGISTER), subsequent requests to mmap the BAR or export it as a DMABUF are rejected with -EBUSY. Signed-off-by: Pranjal Shrivastava --- drivers/vfio/pci/vfio_pci_core.c | 7 +++++++ drivers/vfio/pci/vfio_pci_dmabuf.c | 6 ++++++ 2 files changed, 13 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 1e922e3aaeb3..9cf494b765e7 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -1828,6 +1828,13 @@ int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma if (!vdev->bar_mmap_supported[index]) return -EINVAL; + if (vdev->p2p_registered_bars & (1 << index)) { + pci_warn(vdev->pdev, + "BAR %d registered for P2P. Use sysfs to allocate\n", + index); + return -EBUSY; + } + phys_len = PAGE_ALIGN(pci_resource_len(pdev, index)); req_len = vma->vm_end - vma->vm_start; pgoff = vma->vm_pgoff & diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index c16f460c01d6..6635a8681291 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -251,6 +251,12 @@ int vfio_pci_core_feature_dma_buf(struct vfio_pci_core_device *vdev, u32 flags, IS_ERR(vfio_pci_core_get_iomap(vdev, get_dma_buf.region_index))) return -ENODEV; + if (vdev->p2p_registered_bars & (1 << get_dma_buf.region_index)) { + pci_warn(vdev->pdev, "BAR %d registered for native P2P. Use sysfs for allocation.\n", + get_dma_buf.region_index); + return -EBUSY; + } + dma_ranges = memdup_array_user(&arg->dma_ranges, get_dma_buf.nr_ranges, sizeof(*dma_ranges)); if (IS_ERR(dma_ranges)) -- 2.54.0.1099.g489fc7bff1-goog