Re: [PATCH v2 4/4] vfio/ccw: Make vfio_ccw_register_irq_notifier() return a bool

[Markus Armbruster <armbru@redhat.com>]

Cédric Le Goater <clg@redhat.com> writes:

> Since vfio_ccw_register_irq_notifier() takes an 'Error **' argument,
> best practices suggest to return a bool. See the qapi/error.h Rules
> section.
>
> Signed-off-by: Cédric Le Goater <clg@redhat.com>
> ---
>  hw/vfio/ccw.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index 6764388bc47a970329fce2233626ccb8178e0165..1c630f6e9abe93ae0c2b5615d4409669f096c8c9 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -379,7 +379,7 @@ read_err:
>      css_inject_io_interrupt(sch);
>  }
>  
> -static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
> +static bool vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
>                                             unsigned int irq,
>                                             Error **errp)
>  {
> @@ -405,13 +405,13 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
>          break;
>      default:
>          error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
> -        return;
> +        return false;
>      }
>  
>      if (vdev->num_irqs < irq + 1) {
>          error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
>                     irq, vdev->num_irqs);
> -        return;
> +        return false;
>      }
>  
>      argsz = sizeof(*irq_info);
> @@ -421,14 +421,14 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
>      if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
>                irq_info) < 0 || irq_info->count < 1) {
>          error_setg_errno(errp, errno, "vfio: Error getting irq info");
> -        return;
> +        return false;
>      }
>  
>      if (event_notifier_init(notifier, 0)) {
>          error_setg_errno(errp, errno,
>                           "vfio: Unable to init event notifier for irq (%d)",
>                           irq);
> -        return;
> +        return false;
>      }
>  
>      fd = event_notifier_get_fd(notifier);
> @@ -439,6 +439,8 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
>          qemu_set_fd_handler(fd, NULL, NULL, vcdev);
>          event_notifier_cleanup(notifier);
>      }
> +
> +    return true;
>  }
>  
>  static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
> @@ -602,20 +604,18 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
>          goto out_region_err;
>      }
>  
> -    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
> -    if (err) {
> +    if (!vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err)) {

Please pass errp instead of &err.

>          goto out_io_notifier_err;
>      }
>  
>      if (vcdev->crw_region) {
> -        vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
> -        if (err) {
> +        if (!vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX,
> +                                            &err)) {

Likewise.

>              goto out_irq_notifier_err;
>          }
>      }
>  
> -    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
> -    if (err) {
> +    if (!vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err)) {
>          /*
>           * Report this error, but do not make it a failing condition.
>           * Lack of this IRQ in the host does not prevent normal operation.
            */
           error_report_err(err);

Not this patch's problem, but here goes anyway: since this isn't an
error, we shouldn't use error_report_err().  Would warn_report_err() be
appropriate?  info_report_err() doesn't exist, but it could.

Preferably with errp instead of &err (two times):
Reviewed-by: Markus Armbruster <armbru@redhat.com>