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

["Cédric Le Goater" <clg@redhat.com>]

On 4/25/24 14:55, Eric Farman wrote:
> On Thu, 2024-04-25 at 12:56 +0200, Markus Armbruster wrote:
>> 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..1c630f6e9abe93ae0c2b5615d
>>> 4409669f096c8c9 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>
>>
> 
> Don't recall why I used error_report_err() instead of something else
> (or creating info_), but probably just familiarity. There's no need for
> it (or the equivalent code in -ap) to be error, and could be another
> cleanup.

yes. I will send an extra cleanup to replace error_... with warn_...
and another one to use errp.

Thanks,

C.


> 
> Reviewed-by: Eric Farman <farman@linux.ibm.com>