Re: [PATCH] xen/arm: p2m: fix pa_range_info for 52-bit pa range

[Julien Grall <julien@xxxxxxx>]

Hi Xenia,

On 17/10/2022 18:32, Xenia Ragiadakou wrote:
> Currently the pa_range_info for the 52-bit pa range advertizes that the
> p2m root table consists of 8 concatenated tables at level 3, which does
> not make much sense.
> In order to support the 52-bit pa size with 4KB granule, the p2m root
> table needs to be configured either as a single table at level -1 or
> as 16 concatenated tables at level 0.
> Since, currently there is not support for level -1, set the
> root_order and sl0 fields of the corresponding pa_range_info according
> to the second approach.
Please add a Fixes tag. Also, it would be good to provide a reference to 
the Arm Arm (paragraph + version) so it is easier to find where your 
values come from.
Cheers,

> Signed-off-by: Xenia Ragiadakou <burzalodowa@xxxxxxxxx>
> ---
>   xen/arch/arm/p2m.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index f17500ddf3..c824d62806 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -2251,7 +2251,7 @@ void __init setup_virt_paging(void)
>           [3] = { 42,      22/*22*/,  3,          1 },
>           [4] = { 44,      20/*20*/,  0,          2 },
>           [5] = { 48,      16/*16*/,  0,          2 },
> -        [6] = { 52,      12/*12*/,  3,          3 },
> +        [6] = { 52,      12/*12*/,  4,          2 },
>           [7] = { 0 }  /* Invalid */
>       };
>   
--
Julien Grall