On Sat, Apr 29, 2023 at 12:37 AM Weiwei Li wrote:
>
> RLB/MML/MMWP bits in mseccfg CSR are introduced by Smepmp extension.
> So they can only be writable and set to 1s when cfg.epmp is true.
> Then we also need't check on epmp in pmp_hart_has_privs_default().
>
> Signed-off-by: Weiwei Li
> Signed-off-by: Junqiang Wang
Reviewed-by: Alistair Francis
Alistair
> ---
> target/riscv/pmp.c | 50 --
> 1 file changed, 26 insertions(+), 24 deletions(-)
>
> diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
> index b5808538aa..e745842973 100644
> --- a/target/riscv/pmp.c
> +++ b/target/riscv/pmp.c
> @@ -243,30 +243,28 @@ static bool pmp_hart_has_privs_default(CPURISCVState
> *env, target_ulong addr,
> {
> bool ret;
>
> -if (riscv_cpu_cfg(env)->epmp) {
> -if (MSECCFG_MMWP_ISSET(env)) {
> -/*
> - * The Machine Mode Whitelist Policy (mseccfg.MMWP) is set
> - * so we default to deny all, even for M-mode.
> - */
> +if (MSECCFG_MMWP_ISSET(env)) {
> +/*
> + * The Machine Mode Whitelist Policy (mseccfg.MMWP) is set
> + * so we default to deny all, even for M-mode.
> + */
> +*allowed_privs = 0;
> +return false;
> +} else if (MSECCFG_MML_ISSET(env)) {
> +/*
> + * The Machine Mode Lockdown (mseccfg.MML) bit is set
> + * so we can only execute code in M-mode with an applicable
> + * rule. Other modes are disabled.
> + */
> +if (mode == PRV_M && !(privs & PMP_EXEC)) {
> +ret = true;
> +*allowed_privs = PMP_READ | PMP_WRITE;
> +} else {
> +ret = false;
> *allowed_privs = 0;
> -return false;
> -} else if (MSECCFG_MML_ISSET(env)) {
> -/*
> - * The Machine Mode Lockdown (mseccfg.MML) bit is set
> - * so we can only execute code in M-mode with an applicable
> - * rule. Other modes are disabled.
> - */
> -if (mode == PRV_M && !(privs & PMP_EXEC)) {
> -ret = true;
> -*allowed_privs = PMP_READ | PMP_WRITE;
> -} else {
> -ret = false;
> -*allowed_privs = 0;
> -}
> -
> -return ret;
> }
> +
> +return ret;
> }
>
> if (!riscv_cpu_cfg(env)->pmp || (mode == PRV_M)) {
> @@ -580,8 +578,12 @@ void mseccfg_csr_write(CPURISCVState *env, target_ulong
> val)
> }
> }
>
> -/* Sticky bits */
> -val |= (env->mseccfg & (MSECCFG_MMWP | MSECCFG_MML));
> +if (riscv_cpu_cfg(env)->epmp) {
> +/* Sticky bits */
> +val |= (env->mseccfg & (MSECCFG_MMWP | MSECCFG_MML));
> +} else {
> +val &= ~(MSECCFG_MMWP | MSECCFG_MML | MSECCFG_RLB);
> +}
>
> env->mseccfg = val;
> }
> --
> 2.25.1
>
>
