target/riscv: Legalize MPP value in write_mstatus

mstatus.MPP field is a WARL field since priv version 1.11, so we
remain it unchanged if an invalid value is written into it. And
after this, RVH shouldn't be passed to riscv_cpu_set_mode().

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230407014743.18779-4-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Weiwei Li 2023-04-07 09:47:43 +08:00 committed by Alistair Francis
parent 44b8f74b00
commit 0c98ccef49
2 changed files with 34 additions and 6 deletions

View file

@ -647,12 +647,8 @@ void riscv_cpu_set_aia_ireg_rmw_fn(CPURISCVState *env, uint32_t priv,
void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
{
if (newpriv > PRV_M) {
g_assert_not_reached();
}
if (newpriv == PRV_RESERVED) {
newpriv = PRV_U;
}
g_assert(newpriv <= PRV_M && newpriv != PRV_RESERVED);
if (icount_enabled() && newpriv != env->priv) {
riscv_itrigger_update_priv(env);
}

View file

@ -1230,6 +1230,32 @@ static bool validate_vm(CPURISCVState *env, target_ulong vm)
satp_mode_max_from_map(riscv_cpu_cfg(env)->satp_mode.map);
}
static target_ulong legalize_mpp(CPURISCVState *env, target_ulong old_mpp,
target_ulong val)
{
bool valid = false;
target_ulong new_mpp = get_field(val, MSTATUS_MPP);
switch (new_mpp) {
case PRV_M:
valid = true;
break;
case PRV_S:
valid = riscv_has_ext(env, RVS);
break;
case PRV_U:
valid = riscv_has_ext(env, RVU);
break;
}
/* Remain field unchanged if new_mpp value is invalid */
if (!valid) {
val = set_field(val, MSTATUS_MPP, old_mpp);
}
return val;
}
static RISCVException write_mstatus(CPURISCVState *env, int csrno,
target_ulong val)
{
@ -1237,6 +1263,12 @@ static RISCVException write_mstatus(CPURISCVState *env, int csrno,
uint64_t mask = 0;
RISCVMXL xl = riscv_cpu_mxl(env);
/*
* MPP field have been made WARL since priv version 1.11. However,
* legalization for it will not break any software running on 1.10.
*/
val = legalize_mpp(env, get_field(mstatus, MSTATUS_MPP), val);
/* flush tlb on mstatus fields that affect VM */
if ((val ^ mstatus) & (MSTATUS_MXR | MSTATUS_MPP | MSTATUS_MPV |
MSTATUS_MPRV | MSTATUS_SUM)) {