From 61ceaf236115f20f4fdd7cf60f883ada1063349a Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Wed, 21 Jan 2026 17:45:02 +0200 Subject: [PATCH] vfio: Prevent from pinned DMABUF importers to attach to VFIO DMABUF Some pinned importers, such as non-ODP RDMA ones, cannot invalidate their mappings and therefore must be prevented from attaching to this exporter. Fixes: 5d74781ebc86 ("vfio/pci: Add dma-buf export support for MMIO regions") Signed-off-by: Leon Romanovsky Reviewed-by: Pranjal Shrivastava Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20260121-vfio-add-pin-v1-1-4e04916b17f1@nvidia.com Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci_dmabuf.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index d4d0f7d08c53..4be4a85005cb 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -20,6 +20,16 @@ struct vfio_pci_dma_buf { u8 revoked : 1; }; +static int vfio_pci_dma_buf_pin(struct dma_buf_attachment *attachment) +{ + return -EOPNOTSUPP; +} + +static void vfio_pci_dma_buf_unpin(struct dma_buf_attachment *attachment) +{ + /* Do nothing */ +} + static int vfio_pci_dma_buf_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment) { @@ -76,6 +86,8 @@ static void vfio_pci_dma_buf_release(struct dma_buf *dmabuf) } static const struct dma_buf_ops vfio_pci_dmabuf_ops = { + .pin = vfio_pci_dma_buf_pin, + .unpin = vfio_pci_dma_buf_unpin, .attach = vfio_pci_dma_buf_attach, .map_dma_buf = vfio_pci_dma_buf_map, .unmap_dma_buf = vfio_pci_dma_buf_unmap, -- 2.47.3