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

[Matthew Rosato]

On 9/15/20 2:16 AM, Philippe Mathieu-Daudé wrote:
> 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?

Fair question.  I did originally do this collapsing first, but I wasn't 
sure if Alex would want it so I split it out and tacked it on the end so 
it could be dropped if desired.

I'd be just fine re-arranging and putting this patch first.

> > 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,