Re: [PATCH] target/arm: fix s2mmu input size check

[Richard Henderson <richard.henderson@linaro.org>]

On 5/4/22 22:12, mkei@sfc.wide.ad.jp wrote:
> From: Keisuke Iida <mkei@sfc.wide.ad.jp>
> 
> The maximum IPA size('inputsize') is constrained by the implemented PA size that is
> specified by ID_AA64MMFR0_EL1.PARange. Please reference Arm Architecture Reference
> Manual for A-profile architecture "Supported IPA size" on page D5-4788.
> 
> Signed-off-by: Keisuke Iida <mkei@sfc.wide.ad.jp>
> ---
>   target/arm/helper.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 5a244c3ed9..868e7a2c0b 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -11116,7 +11116,7 @@ static bool check_s2_mmu_setup(ARMCPU *cpu, bool is_aa64, int level,
>           }
>   
>           /* Inputsize checks.  */
> -        if (inputsize > outputsize &&
> +        if (inputsize > arm_pamax(cpu) &&


This is incorrect -- arm_pamax has already been taken into account in computing 
outputsize.  There are many more constraints than just this.

You need to have a look at the computation of ps and tsz in aa64_va_parameters, and then 
the computation of outputsize near the beginning of get_phys_addr_lpae, which takes 
arm_pamax into account by bounding ps against ID_AA64MMFR0.PARANGE, and pamax_map.

What problem are you encountering?


r~