From: Leon Romanovsky <[email protected]> An importer attached to a VFIO dma-buf cannot tell whether its peer-to-peer traffic would reach the exported BAR directly, because the &struct p2pdma_provider describing it stays in vfio_pci_dma_buf.
Implement @p2pdma_provider so dma_buf_p2pdma_map_type() can reach it. Refuse once the buffer is revoked: vfio_pci_dma_buf_cleanup() revokes before it drops the device registration that keeps the provider allocated, so a revoked buffer has nothing left to describe. Tested-by: Tushar Dave <[email protected]> Signed-off-by: Leon Romanovsky <[email protected]> --- 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 c16f460c01d6..fcf392cfc3c5 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -99,11 +99,23 @@ static void vfio_pci_dma_buf_release(struct dma_buf *dmabuf) kfree(priv); } +static struct p2pdma_provider * +vfio_pci_dma_buf_provider(struct dma_buf *dmabuf) +{ + struct vfio_pci_dma_buf *priv = dmabuf->priv; + + if (priv->revoked) + return NULL; + + return priv->provider; +} + static const struct dma_buf_ops vfio_pci_dmabuf_ops = { .attach = vfio_pci_dma_buf_attach, .map_dma_buf = vfio_pci_dma_buf_map, .unmap_dma_buf = vfio_pci_dma_buf_unmap, .release = vfio_pci_dma_buf_release, + .p2pdma_provider = vfio_pci_dma_buf_provider, }; /* -- 2.55.0
