Re: [qemu-s390x] [PATCH] vfio-ccw: use vfio_set_irq_signaling

[Auger Eric]

Hi Eric,

On 6/14/19 4:30 PM, Eric Farman wrote:
> 
> 
> On 6/14/19 5:27 AM, Cornelia Huck wrote:
>> Use the new helper.
>>
>> Signed-off-by: Cornelia Huck <address@hidden>
>> ---
>>  hw/vfio/ccw.c | 68 +++++++++++----------------------------------------
>>  1 file changed, 14 insertions(+), 54 deletions(-)
>>
>> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
>> index 03a2becb3ec9..3dc08721a3db 100644
>> --- a/hw/vfio/ccw.c
>> +++ b/hw/vfio/ccw.c
>> @@ -197,10 +197,7 @@ read_err:
>>  static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error 
>> **errp)
>>  {
>>      VFIODevice *vdev = &vcdev->vdev;
>> -    struct vfio_irq_info *irq_info;
>> -    struct vfio_irq_set *irq_set;
>> -    size_t argsz;
>> -    int32_t *pfd;
>> +    int fd;
>>  
>>      if (vdev->num_irqs < VFIO_CCW_IO_IRQ_INDEX + 1) {
>>          error_setg(errp, "vfio: unexpected number of io irqs %u",
>> @@ -208,72 +205,35 @@ static void 
>> vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp)
>>          return;
>>      }
>>  
>> -    argsz = sizeof(*irq_info);
>> -    irq_info = g_malloc0(argsz);
>> -    irq_info->index = VFIO_CCW_IO_IRQ_INDEX;
>> -    irq_info->argsz = argsz;
>> -    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");
>> -        goto out_free_info;
>> -    }
>> -
> 
> Don't we still need this hunk?  (And the out_free_info label stuff that
> cleans it up.)  I don't see vfio_set_irq_signaling() covering it.

Looks this IRQ index is always implemented and exposed by the driver,
isn't it? In such a case it shouldn't be needed to test its presence?

Thanks

Eric
> 
>>      if (event_notifier_init(&vcdev->io_notifier, 0)) {
>>          error_setg_errno(errp, errno,
>>                           "vfio: Unable to init event notifier for IO");
>> -        goto out_free_info;
>> +        return;
>>      }
>>  
>> -    argsz = sizeof(*irq_set) + sizeof(*pfd);
>> -    irq_set = g_malloc0(argsz);
>> -    irq_set->argsz = argsz;
>> -    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
>> -                     VFIO_IRQ_SET_ACTION_TRIGGER;
>> -    irq_set->index = VFIO_CCW_IO_IRQ_INDEX;
>> -    irq_set->start = 0;
>> -    irq_set->count = 1;
>> -    pfd = (int32_t *) &irq_set->data;
>> -
>> -    *pfd = event_notifier_get_fd(&vcdev->io_notifier);
>> -    qemu_set_fd_handler(*pfd, vfio_ccw_io_notifier_handler, NULL, vcdev);
>> -    if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
>> -        error_setg(errp, "vfio: Failed to set up io notification");
>> -        qemu_set_fd_handler(*pfd, NULL, NULL, vcdev);
>> +    fd = event_notifier_get_fd(&vcdev->io_notifier);
>> +    qemu_set_fd_handler(fd, vfio_ccw_io_notifier_handler, NULL, vcdev);
>> +
>> +    if (vfio_set_irq_signaling(vdev, VFIO_CCW_IO_IRQ_INDEX, 0,
>> +                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
>> +        qemu_set_fd_handler(fd, NULL, NULL, vcdev);
> 
> This sure looks nice though.  :)
> 
>>          event_notifier_cleanup(&vcdev->io_notifier);
>>      }
>> -
>> -    g_free(irq_set);
>> -
>> -out_free_info:
>> -    g_free(irq_info);
>>  }
>>  
>>  static void vfio_ccw_unregister_io_notifier(VFIOCCWDevice *vcdev)
>>  {
>> -    struct vfio_irq_set *irq_set;
>> -    size_t argsz;
>> -    int32_t *pfd;
>> -
>> -    argsz = sizeof(*irq_set) + sizeof(*pfd);
>> -    irq_set = g_malloc0(argsz);
>> -    irq_set->argsz = argsz;
>> -    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
>> -                     VFIO_IRQ_SET_ACTION_TRIGGER;
>> -    irq_set->index = VFIO_CCW_IO_IRQ_INDEX;
>> -    irq_set->start = 0;
>> -    irq_set->count = 1;
>> -    pfd = (int32_t *) &irq_set->data;
>> -    *pfd = -1;
>> -
>> -    if (ioctl(vcdev->vdev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
>> -        error_report("vfio: Failed to de-assign device io fd: %m");
>> +    Error *err = NULL;
>> +
>> +    vfio_set_irq_signaling(&vcdev->vdev, VFIO_CCW_IO_IRQ_INDEX, 0,
>> +                           VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err);
>> +    if (err) {
>> +        error_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
>>      }
>>  
>>      qemu_set_fd_handler(event_notifier_get_fd(&vcdev->io_notifier),
>>                          NULL, NULL, vcdev);
>>      event_notifier_cleanup(&vcdev->io_notifier);
>> -
>> -    g_free(irq_set);
>>  }
>>  
>>  static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
>>
>