Merge tag 'vfio-v6.19-rc8' of https://github.com/awilliam/linux-vfio

Pull VFIO fix from Alex Williamson:

 - Fix a gap in the initial VFIO DMABUF implementation where it's
   required to explicitly implement a failing pin callback to prevent
   pinned importers that cannot properly support move_notify.
   (Leon Romanovsky)

* tag 'vfio-v6.19-rc8' of https://github.com/awilliam/linux-vfio:
  vfio: Prevent from pinned DMABUF importers to attach to VFIO DMABUF

Author: torvalds

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,