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

[Matthew Rosato <mjrosato@linux.ibm.com>]

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,
>>
>