Re: [PATCH v2 3/3] vfio: Create shared routine for scanning info capabilities

[Philippe Mathieu-Daudé]

On 9/15/20 12:29 AM, Matthew Rosato wrote:
> Rather than duplicating the same loop in multiple locations,
> create a static function to do the work.

Why not do that first in your series?

> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
>  hw/vfio/common.c | 33 +++++++++++++++------------------
>  1 file changed, 15 insertions(+), 18 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 7f4a338..bfbbfe4 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -825,17 +825,12 @@ static void vfio_listener_release(VFIOContainer 
> *container)
>      }
>  }
>  
> -struct vfio_info_cap_header *
> -vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id)
> +static struct vfio_info_cap_header *
> +vfio_get_cap(void *ptr, uint32_t cap_offset, uint16_t id)
>  {
>      struct vfio_info_cap_header *hdr;
> -    void *ptr = info;
> -
> -    if (!(info->flags & VFIO_REGION_INFO_FLAG_CAPS)) {
> -        return NULL;
> -    }
>  
> -    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
> +    for (hdr = ptr + cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
>          if (hdr->id == id) {
>              return hdr;
>          }
> @@ -844,23 +839,25 @@ vfio_get_region_info_cap(struct vfio_region_info *info, 
> uint16_t id)
>      return NULL;
>  }
>  
> +
> +struct vfio_info_cap_header *
> +vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id)
> +{
> +    if (!(info->flags & VFIO_REGION_INFO_FLAG_CAPS)) {
> +        return NULL;
> +    }
> +
> +    return vfio_get_cap((void *)info, info->cap_offset, id);
> +}
> +
>  static struct vfio_info_cap_header *
>  vfio_get_iommu_type1_info_cap(struct vfio_iommu_type1_info *info, uint16_t 
> id)
>  {
> -    struct vfio_info_cap_header *hdr;
> -    void *ptr = info;
> -
>      if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {
>          return NULL;
>      }
>  
> -    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
> -        if (hdr->id == id) {
> -            return hdr;
> -        }
> -    }
> -
> -    return NULL;
> +    return vfio_get_cap((void *)info, info->cap_offset, id);
>  }
>  
>  bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info,
>