On Fri, Mar 15, 2024 at 6:31 PM gavin.liu <gavin.liu@xxxxxxxxxxxxxxx> wrote:
>
> From: Yuxue Liu <yuxue.liu@xxxxxxxxxxxxxxx>
>
> Under the VDPA framework, when the VDPA driver of a device sets the status
> to DRIVER OK,success is not guaranteed. The virtio driver should provide
> some protection or notification.
>
> Signed-off-by: Yuxue Liu <yuxue.liu@xxxxxxxxxxxxxxx>
> ---
> drivers/block/virtio_blk.c | 4 +++-
> drivers/net/virtio_net.c | 7 ++++++-
> include/linux/virtio_config.h | 14 ++++++++++++++
> 3 files changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 42dea7601d87..14cabf662705 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -1535,7 +1535,9 @@ static int virtblk_probe(struct virtio_device *vdev)
> set_disk_ro(vblk->disk, 1);
>
> virtblk_update_capacity(vblk, false);
> - virtio_device_ready(vdev);
> + err = virtio_device_ready_safe(vdev);
> + if (err)
> + goto out_cleanup_disk;
>
> /*
> * All steps that follow use the VQs therefore they need to be
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index d7ce4a1011ea..0431fc9095ae 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -4808,7 +4808,12 @@ static int virtnet_probe(struct virtio_device *vdev)
> goto free_failover;
> }
>
> - virtio_device_ready(vdev);
> + err = virtio_device_ready_safe(vdev);
> + if (err) {
> + pr_debug("virtio_net: setting device ready failed\n");
> + rtnl_unlock();
> + goto free_unregister_netdev;
> + }
>
> _virtnet_set_queues(vi, vi->curr_queue_pairs);
>
> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> index da9b271b54db..de4e864952ef 100644
> --- a/include/linux/virtio_config.h
> +++ b/include/linux/virtio_config.h
> @@ -301,6 +301,20 @@ void virtio_device_ready(struct virtio_device *dev)
> dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
> }
>
> +static inline
> +int virtio_device_ready_safe(struct virtio_device *dev)
> +{
> + u8 status;
> +
> + virtio_device_ready(dev);
> + status = dev->config->get_status(dev);
> + if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
> + WARN_ON(1);
> + return -EINVAL;
The seems to be a violation of the virtio spec:
Section 3.1.1 Driver Requirements: Device Initialization said
"""
Set the DRIVER_OK status bit. At this point the device is “live”.
"""
Or why did you need to read the status back and check?
Thanks
> + }
> + return 0;
> +}
> +
> static inline
> const char *virtio_bus_name(struct virtio_device *vdev)
> {
> --
> 2.43.0
>
