Re: [PATCH v14 15/22] vfio: Introduce vfio_set_irqs_validate_and_prepare()

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

Hi,
On 16/11/2016 21:46, Kirti Wankhede wrote:
> Vendor driver using mediated device framework would use same mechnism to
> validate and prepare IRQs. Introducing this function to reduce code
> replication in multiple drivers.
> 
> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> Signed-off-by: Neo Jia <cjia@nvidia.com>
> Change-Id: Ie201f269dda0713ca18a07dc4852500bd8b48309
> ---
>  drivers/vfio/vfio.c  | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/vfio.h |  4 ++++
>  2 files changed, 52 insertions(+)
> 
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 82257cf30f52..2c044af09a2c 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1858,6 +1858,54 @@ int vfio_info_add_capability(struct vfio_info_cap *caps, int cap_type_id,
>  }
>  EXPORT_SYMBOL(vfio_info_add_capability);
>  
> +int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
> +				       int max_irq_type, size_t *data_size)
> +{
> +	unsigned long minsz;
> +	size_t size;
> +
> +	minsz = offsetofend(struct vfio_irq_set, count);
> +
> +	if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
> +	    (hdr->count >= (U32_MAX - hdr->start)) ||
> +	    (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
> +				VFIO_IRQ_SET_ACTION_TYPE_MASK)))
> +		return -EINVAL;
> +
> +	if (data_size)
> +		*data_size = 0;
> +
> +	if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
> +		return -EINVAL;
> +
> +	switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
> +	case VFIO_IRQ_SET_DATA_NONE:
> +		size = 0;
> +		break;
> +	case VFIO_IRQ_SET_DATA_BOOL:
> +		size = sizeof(uint8_t);
> +		break;
> +	case VFIO_IRQ_SET_DATA_EVENTFD:
> +		size = sizeof(int32_t);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (size) {
> +		if (hdr->argsz - minsz < hdr->count * size)
> +			return -EINVAL;
> +
> +		if (!data_size)
> +			return -EINVAL;
nit: this could have done on the first check above.

Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric

> +
> +		*data_size = hdr->count * size;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
> +
>  /*
>   * Pin a set of guest PFNs and return their associated host PFNs for local
>   * domain only.
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index e26f7ccab564..15ff0421b423 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -129,6 +129,10 @@ extern void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
>  extern int vfio_info_add_capability(struct vfio_info_cap *caps,
>  				    int cap_type_id, void *cap_type);
>  
> +extern int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
> +					      int num_irqs, int max_irq_type,
> +					      size_t *data_size);
> +
>  struct pci_dev;
>  #ifdef CONFIG_EEH
>  extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
>