On Sun, 26 Apr 2020 14:35:42 +0800
Yingtai Xie <xieyingtai@xxxxxxxxxx> wrote:
> This is setup the same way as vfio-pci to indicate
> userspace that the device should be released.
Is there an in-kernel user?
> Signed-off-by: Yingtai Xie <xieyingtai@xxxxxxxxxx>
> ---
> drivers/vfio/mdev/vfio_mdev.c | 10 ++++++++++
> include/linux/mdev.h | 4 ++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
> index 30964a4e0..74695c116 100644
> --- a/drivers/vfio/mdev/vfio_mdev.c
> +++ b/drivers/vfio/mdev/vfio_mdev.c
> @@ -98,6 +98,15 @@ static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
> return parent->ops->mmap(mdev, vma);
> }
>
> +static void vfio_mdev_request(void *device_data, unsigned int count)
> +{
> + struct mdev_device *mdev = device_data;
> + struct mdev_parent *parent = mdev->parent;
> +
> + if (likely(!parent->ops->request))
> + parent->ops->request(mdev, count);
> +}
> +
> static const struct vfio_device_ops vfio_mdev_dev_ops = {
> .name = "vfio-mdev",
> .open = vfio_mdev_open,
> @@ -106,6 +115,7 @@ static const struct vfio_device_ops vfio_mdev_dev_ops = {
> .read = vfio_mdev_read,
> .write = vfio_mdev_write,
> .mmap = vfio_mdev_mmap,
> + .request = vfio_mdev_request,
> };
>
> static int vfio_mdev_probe(struct device *dev)
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 0ce30ca78..1ab0b0b9b 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -72,6 +72,9 @@ struct device *mdev_get_iommu_device(struct device *dev);
> * @mmap: mmap callback
> * @mdev: mediated device structure
> * @vma: vma structure
> + * @request request callback
> + * @mdev: mediated device structure
> + * @count: counter to allow driver to release the device
> * Parent device that support mediated device should be registered with mdev
> * module with mdev_parent_ops structure.
> **/
> @@ -92,6 +95,7 @@ struct mdev_parent_ops {
> long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
> unsigned long arg);
> int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
> + int (*request)(struct mdev_device *mdev, unsigned int count);
> };
>
> /* interface for exporting mdev supported type attributes */
