Re: [dpdk-dev] [PATCH 14/15] net/virtio: add vDPA op to get notification area

[Tiwei Bie <tiwei.bie@intel.com>]

On Thu, Aug 29, 2019 at 09:59:59AM +0200, Maxime Coquelin wrote:
> This patch implements the vDPA .get_notify_area()
> callback.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_vdpa.c | 33 ++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/net/virtio/virtio_vdpa.c b/drivers/net/virtio/virtio_vdpa.c
> index e0b2f99ba..e681f527a 100644
> --- a/drivers/net/virtio/virtio_vdpa.c
> +++ b/drivers/net/virtio/virtio_vdpa.c
> @@ -707,6 +707,38 @@ virtio_vdpa_get_vfio_device_fd(int vid)
>  	return list->dev->vfio_dev_fd;
>  }
>  
> +static int
> +virtio_vdpa_get_notify_area(int vid, int qid, uint64_t *offset, uint64_t *size)
> +{
> +	int did;
> +	struct internal_list *list;
> +	struct virtio_vdpa_device *dev;
> +	struct vfio_region_info reg = { .argsz = sizeof(reg) };
> +	int ret;
> +
> +	did = rte_vhost_get_vdpa_device_id(vid);
> +	list = find_internal_resource_by_did(did);
> +	if (list == NULL) {
> +		DRV_LOG(ERR, "Invalid device id: %d", did);
> +		return -1;
> +	}
> +
> +	dev = list->dev;
> +
> +	reg.index = dev->hw.notify_region;
> +	ret = ioctl(dev->vfio_dev_fd, VFIO_DEVICE_GET_REGION_INFO, &reg);
> +	if (ret) {
> +		DRV_LOG(ERR, "Get not get device region info: %s",
> +				strerror(errno));
> +		return -1;
> +	}
> +
> +	*offset = dev->vqs[qid].notify_addr - dev->hw.notify_base + reg.offset;
> +	*size = 0x1000;

It would be better to check whether the size is no less
than 0x1000, otherwise it's possible to give guest the
access to other registers of the vdpa device.

Regards,
Tiwei

> +
> +	return 0;
> +}
> +
>  static struct rte_vdpa_dev_ops virtio_vdpa_ops = {
>  	.get_queue_num = virtio_vdpa_get_queue_num,
>  	.get_features = virtio_vdpa_get_features,
> @@ -716,6 +748,7 @@ static struct rte_vdpa_dev_ops virtio_vdpa_ops = {
>  	.set_features = virtio_vdpa_set_features,
>  	.get_vfio_group_fd = virtio_vdpa_get_vfio_group_fd,
>  	.get_vfio_device_fd = virtio_vdpa_get_vfio_device_fd,
> +	.get_notify_area = virtio_vdpa_get_notify_area,
>  };
>  
>  static inline int
> -- 
> 2.21.0
>