Re: [PATCH] target/riscv: Smepmp: Skip applying default rules when address matches

[Daniel Henrique Barboza]

On 2/9/23 02:52, Himanshu Chauhan wrote:
> When MSECCFG.MML is set, after checking the address range in PMP if the
> asked permissions are not same as programmed in PMP, the default
> permissions are applied. This should only be the case when there
> is no matching address is found.
>
> This patch skips applying default rules when matching address range
> is found. It returns the index of the match PMP entry.
>
> fixes: 824cac681c3 (target/riscv: Fix PMP propagation for tlb)

Nit: tag starts with capital "F":

Fixes: 824cac681c3 (target/riscv: Fix PMP propagation for tlb)

> Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
> ---

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

>   target/riscv/pmp.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
> index d85ad07caa..0dfdb35828 100644
> --- a/target/riscv/pmp.c
> +++ b/target/riscv/pmp.c
> @@ -446,9 +446,12 @@ int pmp_hart_has_privs(CPURISCVState *env, target_ulong 
> addr,
>                   }
>               }
>   
> -            if ((privs & *allowed_privs) == privs) {
> -                ret = i;
> -            }
> +            /*
> +             * If matching address range was found, the protection bits
> +             * defined with PMP must be used. We shouldn't fallback on
> +             * finding default privileges.
> +             */
> +            ret = i;
>               break;
>           }
>       }