Re: [qemu-s390x] [PATCH v3 14/33] hw/s390x/s390-virtio-ccw.c: remove qdev_reset_all call

[Cornelia Huck]

On Mon, 29 Jul 2019 16:56:35 +0200
Damien Hedde <address@hidden> wrote:

> Replace deprecated qdev_reset_all by device_reset_warm.
> 
> This does not impact the behavior.

Not so sure about that; see below.

> 
> Signed-off-by: Damien Hedde <address@hidden>
> ---
>  hw/s390x/s390-virtio-ccw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 5b6a9a4e55..1d6b966817 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -104,7 +104,7 @@ static void subsystem_reset(void)
>      for (i = 0; i < ARRAY_SIZE(reset_dev_types); i++) {
>          dev = DEVICE(object_resolve_path_type("", reset_dev_types[i], NULL));
>          if (dev) {
> -            qdev_reset_all(dev);
> +            device_reset_warm(dev);
>          }
>      }
>  }

This resets various different devices:

- the diag288 watchdog, which does not have kids
- the flic also seems fine (both non-kvm and kvm versions)
- the sclp event facility, however, does have kids:
  - I'm a bit unsure about the sclp cpu hotplug thing; it does not have
    a ->reset function, though
  - the quiesce event does have a ->reset callback; so presumably this
    is already called in a different path
- the css bridge is basically the root of all things css; its ->reset
  function currently calls css_reset(), which resets some state of the
  css per se, but does not call down into the device tree
  - might we end up with calling some stuff twice for devices in the
    css?

Would be good if someone else from the s390 folks could take a look,
just to make sure I'm not confused here.