Re: [RFC 5/8] virtio-ccw: Handle extra notification data

On 01/03/2024 14.43, Jonah Palmer wrote:
> Add support to virtio-ccw devices for handling the extra data sent from
> the driver to the device when the VIRTIO_F_NOTIFICATION_DATA transport
> feature has been negotiated.
> 
> The extra data that's passed to the virtio-ccw device when this feature
> is enabled varies depending on the device's virtqueue layout.
> 
> That data passed to the virtio-ccw device is in the same format as the
> data passed to virtio-pci devices.
> 
> Signed-off-by: Jonah Palmer <[email protected]>
> ---
>   hw/s390x/s390-virtio-ccw.c | 18 ++++++++++++++----
>   1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 62804cc228..b8e193956c 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -140,9 +140,11 @@ static void subsystem_reset(void)
>   static int virtio_ccw_hcall_notify(const uint64_t *args)
>   {
>       uint64_t subch_id = args[0];
> -    uint64_t queue = args[1];
> +    uint64_t data = args[1];
>       SubchDev *sch;
> +    VirtIODevice *vdev;
>       int cssid, ssid, schid, m;
> +    uint16_t vq_idx;
>   
>       if (ioinst_disassemble_sch_ident(subch_id, &m, &cssid, &ssid, &schid)) {
>           return -EINVAL;
> @@ -151,12 +153,20 @@ static int virtio_ccw_hcall_notify(const uint64_t *args)
>       if (!sch || !css_subch_visible(sch)) {
>           return -EINVAL;
>       }
> -    if (queue >= VIRTIO_QUEUE_MAX) {
> +
> +    vdev = virtio_ccw_get_vdev(sch);
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
> +        vq_idx = data & 0xFFFF;
> +        virtio_set_notification_data(vdev, vq_idx, data);
> +    } else {
> +        vq_idx = data;
> +    }
> +
> +    if (vq_idx >= VIRTIO_QUEUE_MAX) {
>           return -EINVAL;
>       }
> -    virtio_queue_notify(virtio_ccw_get_vdev(sch), queue);
> +    virtio_queue_notify(vdev, vq_idx);
>       return 0;
> -
>   }

Acked-by: Thomas Huth <[email protected]>