From: Leon Romanovsky leonro@nvidia.com
DMABUF ->pin() interface is called when the DMABUF importer perform its DMA mapping, so let's use this opportunity to check if DMABUF exporter revoked its buffer or not.
Signed-off-by: Leon Romanovsky leonro@nvidia.com --- drivers/vfio/pci/vfio_pci_dmabuf.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index d4d0f7d08c53..af9c315ddf71 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -20,6 +20,20 @@ struct vfio_pci_dma_buf { u8 revoked : 1; };
+static int vfio_pci_dma_buf_pin(struct dma_buf_attachment *attachment) +{ + struct vfio_pci_dma_buf *priv = attachment->dmabuf->priv; + + dma_resv_assert_held(priv->dmabuf->resv); + + return dma_buf_attachment_is_revoke(attachment) ? 0 : -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 +90,8 @@ 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,