Re: [PATCH v2 2/2] xen/arm: fix iomem_ranges cfg in map_range_to_domain()

[Julien Grall <julien@xxxxxxx>]

Hi Grygorii,

On 18/02/2025 11:22, Grygorii Strashko wrote:
> Now the following code in map_range_to_domain()
>
>   res = rangeset_add_range(mr_data->iomem_ranges,
>                            paddr_to_pfn(addr),
>                            paddr_to_pfn_aligned(addr + len - 1));
>   where
>    paddr_to_pfn_aligned(paddr) defined as paddr_to_pfn(PAGE_ALIGN(paddr))
>
> calculates the iomem range end address by rounding it up to the next Xen
> page with incorrect assumption that iomem range end address passed to
> rangeset_add_range() is exclusive, while it is expected to be inclusive.
>
> For example, if requested range is [00e6140000:00e6141004] then it expected
> to add [e6140:e6141] range (num_pages=2) to the mr_data->iomem_ranges
> rangeset, but will add [e6140:e6142] (num_pages=3) instead.
>
> To fix it, drop PAGE_ALIGN() from the iomem range end address calculation
> formula and just use paddr_to_pfn(addr + len - 1).
>
> Fixes: 57d4d7d4e8f3b (arm/asm/setup.h: Update struct map_range_data to add
> rangeset.")
> Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall