Re: [RFC PATCH 1/4] xen/arm: Add wrapper find_unused_regions

["Orzel, Michal" <michal.orzel@xxxxxxx>]

On 21/06/2025 17:11, Koichiro Den wrote:
> This is preparatory work for the upcoming commits that implement the
> standard PV time interface (ARM DEN 0057A).
I personally don't find such messages useful. If at all, reasoning should be
given first and then this message could appear.

> 
> No functional changes intended.
> 
> Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
> ---
>  xen/arch/arm/domain_build.c | 29 ++++++++++++++++++-----------
>  1 file changed, 18 insertions(+), 11 deletions(-)
> 
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 4ff161887ec3..9d44b6fa9470 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -1070,6 +1070,23 @@ static int __init find_host_extended_regions(const 
> struct kernel_info *kinfo,
>      return res;
>  }
>  
> +static int __init find_unused_regions(struct domain *d,
> +                                      const struct kernel_info *kinfo,
Let's not propagate unjustified (IMO) behavior of passing both domain and kinfo
pointers. The latter contains the domain member and therefore is sufficient as
argument.

> +                                      struct membanks *ext_regions)
> +{
> +    if ( domain_use_host_layout(d) )
> +    {
> +        if ( !is_iommu_enabled(d) )
> +            return find_host_extended_regions(kinfo, ext_regions);
> +        else
> +            return find_memory_holes(kinfo, ext_regions);
> +    }
> +    else
> +    {
You can take opportunity to drop unneeded braces

Otherwise, LGTM.

~Michal