Re: [Qemu-devel] [PATCH v5] vfio/common: Introduce vfio_set_irq_signaling helper

[Auger Eric <eric.auger@redhat.com>]

Hi Connie,

On 6/12/19 6:46 PM, Cornelia Huck wrote:
> On Wed, 12 Jun 2019 14:40:04 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
> 
>> The code used to assign an interrupt index/subindex to an
>> eventfd is duplicated many times. Let's introduce an helper that
>> allows to set/unset the signaling for an ACTION_TRIGGER,
>> ACTION_MASK or ACTION_UNMASK action.
>>
>> In the error message, we now use errno in case of any
>> VFIO_DEVICE_SET_IRQS ioctl failure.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> Looks good to me.
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>

thank you!
> 
> I currently have the following, still untested patch on top (vfio-ap
> doesn't use this ioctl):
> 
> From 9c2efe73d6139e8c7b2109ac2df79fe073d942fb Mon Sep 17 00:00:00 2001
> From: Cornelia Huck <cohuck@redhat.com>
> Date: Wed, 12 Jun 2019 18:42:29 +0200
> Subject: [PATCH] vfio-ccw: use vfio_set_irq_signaling()
> 
> Make use of the new helper.
> 
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
>  hw/vfio/ccw.c | 50 +++++++++++++-------------------------------------
>  1 file changed, 13 insertions(+), 37 deletions(-)
> 
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index 03a2becb3ec9..3643be0ee254 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -198,9 +198,9 @@ 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;
> +    Error *local_err = NULL;
>  
>      if (vdev->num_irqs < VFIO_CCW_IO_IRQ_INDEX + 1) {
>          error_setg(errp, "vfio: unexpected number of io irqs %u",
> @@ -224,56 +224,32 @@ static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp)
>          goto out_free_info;
>      }
>  
> -    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, &local_err)) {
> +        error_propagate(errp, local_err);
> +        qemu_set_fd_handler(fd, NULL, NULL, vcdev);
>          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 *local_err = NULL;
> +
> +    if (vfio_set_irq_signaling(&vcdev->vdev, VFIO_CCW_IO_IRQ_INDEX, 0,
> +                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &local_err)) {
> +        error_report_err(local_err);
>      }
>  
>      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)
> 
Looks good. Looking forward to reviewing it formally.

Best Regards

Eric