A driver that doesn't implement ops->dma_unmap shouldn't be allowed to do vfio_pin/unpin_pages(), though it can use vfio_dma_rw() to access an iova range. Deny !ops->dma_unmap cases in vfio_pin/unpin_pages(). Suggested-by: Kevin Tian <kevin.tian@xxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> Reviewed-by: Yi Liu <yi.l.liu@xxxxxxxxx> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Reviewed-by: Alex Williamson <alex.williamson@xxxxxxxxxx> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx> --- drivers/vfio/vfio_main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 902f06e52c48..0da8ed81a97d 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -1483,6 +1483,8 @@ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, /* group->container cannot change while a vfio device is open */ if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device))) return -EINVAL; + if (!device->ops->dma_unmap) + return -EINVAL; if (vfio_device_has_container(device)) return vfio_device_container_pin_pages(device, iova, npage, prot, pages); @@ -1520,6 +1522,8 @@ void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage) { if (WARN_ON(!vfio_assert_device_open(device))) return; + if (WARN_ON(!device->ops->dma_unmap)) + return; if (vfio_device_has_container(device)) { vfio_device_container_unpin_pages(device, iova, npage); -- 2.41.0