Re: [PATCH vhost 2/2] vdpa/mlx5: Fix suboptimal range on iotlb iteration

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Oct 21, 2024 at 04:40:40PM +0300, Dragos Tatulea wrote:
> From: Si-Wei Liu <si-wei.liu@oracle.com>
> 
> The starting iova address to iterate iotlb map entry within a range
> was set to an irrelevant value when passing to the itree_next()
> iterator, although luckily it doesn't affect the outcome of finding
> out the granule of the smallest iotlb map size. Fix the code to make
> it consistent with the following for-loop.
> 
> Fixes: 94abbccdf291 ("vdpa/mlx5: Add shared memory registration code")


But the cover letter says "that's why it does not have a fixes tag".
Confused.

> Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
> Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
> ---
>  drivers/vdpa/mlx5/core/mr.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> index 7d0c83b5b071..8455f08f5d40 100644
> --- a/drivers/vdpa/mlx5/core/mr.c
> +++ b/drivers/vdpa/mlx5/core/mr.c
> @@ -368,7 +368,6 @@ static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
>  	unsigned long lgcd = 0;
>  	int log_entity_size;
>  	unsigned long size;
> -	u64 start = 0;
>  	int err;
>  	struct page *pg;
>  	unsigned int nsg;
> @@ -379,10 +378,9 @@ static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr
>  	struct device *dma = mvdev->vdev.dma_dev;
>  
>  	for (map = vhost_iotlb_itree_first(iotlb, mr->start, mr->end - 1);
> -	     map; map = vhost_iotlb_itree_next(map, start, mr->end - 1)) {
> +	     map; map = vhost_iotlb_itree_next(map, mr->start, mr->end - 1)) {
>  		size = maplen(map, mr);
>  		lgcd = gcd(lgcd, size);
> -		start += size;
>  	}
>  	log_entity_size = ilog2(lgcd);
>  
> -- 
> 2.46.1