Re: [PATCH 1/3] vfio: ap: realize the VFIO_DEVICE_GET_IRQ_INFO ioctl

[Cédric Le Goater <clegoate@xxxxxxxxxx>]

On 5/31/23 00:35, Tony Krowiak wrote:
> Realize the VFIO_DEVICE_GET_IRQ_INFO ioctl to retrieve the information for
> the VFIO device request IRQ.
>
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>

Reviewed-by: Cédric Le Goater <clg@xxxxxxxxxx>

Thanks,

C.


> ---
>   drivers/s390/crypto/vfio_ap_ops.c | 30 +++++++++++++++++++++++++++++-
>   include/uapi/linux/vfio.h         |  9 +++++++++
>   2 files changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index cfbcb864ab63..35cd90eee937 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -1750,7 +1750,32 @@ static int vfio_ap_mdev_get_device_info(unsigned long arg)
>   
>   	info.flags = VFIO_DEVICE_FLAGS_AP | VFIO_DEVICE_FLAGS_RESET;
>   	info.num_regions = 0;
> -	info.num_irqs = 0;
> +	info.num_irqs = VFIO_AP_NUM_IRQS;
> +
> +	return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
> +}
> +
> +static ssize_t vfio_ap_get_irq_info(unsigned long arg)
> +{
> +	unsigned long minsz;
> +	struct vfio_irq_info info;
> +
> +	minsz = offsetofend(struct vfio_irq_info, count);
> +
> +	if (copy_from_user(&info, (void __user *)arg, minsz))
> +		return -EFAULT;
> +
> +	if (info.argsz < minsz || info.index >= VFIO_AP_NUM_IRQS)
> +		return -EINVAL;
> +
> +	switch (info.index) {
> +	case VFIO_AP_REQ_IRQ_INDEX:
> +		info.count = 1;
> +		info.flags = VFIO_IRQ_INFO_EVENTFD;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
>   
>   	return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
>   }
> @@ -1770,6 +1795,9 @@ static ssize_t vfio_ap_mdev_ioctl(struct vfio_device *vdev,
>   	case VFIO_DEVICE_RESET:
>   		ret = vfio_ap_mdev_reset_queues(&matrix_mdev->qtable);
>   		break;
> +	case VFIO_DEVICE_GET_IRQ_INFO:
> +			ret = vfio_ap_get_irq_info(arg);
> +			break;
>   	default:
>   		ret = -EOPNOTSUPP;
>   		break;
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 0552e8dcf0cb..b71276bd7f91 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -646,6 +646,15 @@ enum {
>   	VFIO_CCW_NUM_IRQS
>   };
>   
> +/*
> + * The vfio-ap bus driver makes use of the following IRQ index mapping.
> + * Unimplemented IRQ types return a count of zero.
> + */
> +enum {
> +	VFIO_AP_REQ_IRQ_INDEX,
> +	VFIO_AP_NUM_IRQS
> +};
> +
>   /**
>    * VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 12,
>    *					      struct vfio_pci_hot_reset_info)