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 <liwei...@iscas.ac.cn> Signed-off-by: Junqiang Wang <wangjunqi...@iscas.ac.cn> --- target/riscv/cpu_helper.c | 5 +---- target/riscv/csr.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 2310c7905f..6148f221c3 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -647,12 +647,9 @@ 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) { + if (newpriv > PRV_M || newpriv == PRV_H) { g_assert_not_reached(); } - if (newpriv == PRV_H) { - newpriv = PRV_U; - } if (icount_enabled() && newpriv != env->priv) { riscv_itrigger_update_priv(env); } diff --git a/target/riscv/csr.c b/target/riscv/csr.c index e0b871f6dc..f3ae726853 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -1230,6 +1230,18 @@ 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) +{ + target_ulong new_mpp = get_field(val, MSTATUS_MPP); + bool mpp_invalid = (new_mpp == PRV_S && !riscv_has_ext(env, RVS)) || + (new_mpp == PRV_U && !riscv_has_ext(env, RVU)) || + (new_mpp == PRV_H); + + /* Remain field unchanged if new_mpp value is invalid */ + return mpp_invalid ? set_field(val, MSTATUS_MPP, old_mpp) : val; +} + static RISCVException write_mstatus(CPURISCVState *env, int csrno, target_ulong val) { @@ -1237,6 +1249,12 @@ 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)) { -- 2.25.1