From: Hou Weiying <weiying_...@outlook.com> This commit adds support for ePMP v0.9.1.
The ePMP spec can be found in: https://docs.google.com/document/d/1Mh_aiHYxemL0umN3GTTw8vsbmzHZ_nxZXgjgOUzbvc8 Signed-off-by: Hongzheng-Li <ethan.lee....@gmail.com> Signed-off-by: Hou Weiying <weiying_...@outlook.com> Signed-off-by: Myriad-Dreamin <camiy...@gmail.com> Message-Id: <sg2pr02mb263462ccdbcbbad36983c2cd93...@sg2pr02mb2634.apcprd02.prod.outlook.com> [ Changes by AF: - Rebase on master - Update to latest spec - Use a switch case to handle ePMP MML permissions - Fix a few bugs ] Signed-off-by: Alistair Francis <alistair.fran...@wdc.com> --- target/riscv/pmp.c | 165 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 153 insertions(+), 12 deletions(-) diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index 1d071b044b..3794c808e8 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -90,11 +90,42 @@ static inline uint8_t pmp_read_cfg(CPURISCVState *env, uint32_t pmp_index) static void pmp_write_cfg(CPURISCVState *env, uint32_t pmp_index, uint8_t val) { if (pmp_index < MAX_RISCV_PMPS) { - if (!pmp_is_locked(env, pmp_index)) { - env->pmp_state.pmp[pmp_index].cfg_reg = val; - pmp_update_rule(env, pmp_index); + bool locked = true; + + if (riscv_feature(env, RISCV_FEATURE_EPMP)) { + /* mseccfg.RLB is set */ + if (MSECCFG_RLB_ISSET(env)) { + locked = false; + } + + /* mseccfg.MML is not set */ + if (!MSECCFG_MML_ISSET(env) && !pmp_is_locked(env, pmp_index)) { + locked = false; + } + + /* mseccfg.MML is set */ + if (MSECCFG_MML_ISSET(env)) { + /* not adding execute bit */ + if ((val & PMP_LOCK) != 0 && (val & PMP_EXEC) != PMP_EXEC) { + locked = false; + } + /* shared region and not adding X bit*/ + if ((val & PMP_LOCK) != PMP_LOCK && + (val & 0x7) != (PMP_WRITE | PMP_EXEC)) { + locked = false; + } + } } else { + if (!pmp_is_locked(env, pmp_index)) { + locked = false; + } + } + + if (locked) { qemu_log_mask(LOG_GUEST_ERROR, "ignoring pmpcfg write - locked\n"); + } else { + env->pmp_state.pmp[pmp_index].cfg_reg = val; + pmp_update_rule(env, pmp_index); } } else { qemu_log_mask(LOG_GUEST_ERROR, @@ -217,6 +248,33 @@ static bool pmp_hart_has_privs_default(CPURISCVState *env, target_ulong addr, { bool ret; + if (riscv_feature(env, RISCV_FEATURE_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. + */ + *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; + } + } + if ((!riscv_feature(env, RISCV_FEATURE_PMP)) || (mode == PRV_M)) { /* * Privileged spec v1.10 states if HW doesn't implement any PMP entry @@ -294,13 +352,94 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr, pmp_get_a_field(env->pmp_state.pmp[i].cfg_reg); /* - * If the PMP entry is not off and the address is in range, do the priv - * check + * Convert the PMP permissions to match the truth table in the + * ePMP spec. */ + const uint8_t epmp_operation = + ((env->pmp_state.pmp[i].cfg_reg & PMP_LOCK) >> 4) | + ((env->pmp_state.pmp[i].cfg_reg & PMP_READ) << 2) | + (env->pmp_state.pmp[i].cfg_reg & PMP_WRITE) | + ((env->pmp_state.pmp[i].cfg_reg & PMP_EXEC) >> 2); + if (((s + e) == 2) && (PMP_AMATCH_OFF != a_field)) { - *allowed_privs = PMP_READ | PMP_WRITE | PMP_EXEC; - if ((mode != PRV_M) || pmp_is_locked(env, i)) { - *allowed_privs &= env->pmp_state.pmp[i].cfg_reg; + /* + * If the PMP entry is not off and the address is in range, + * do the priv check + */ + if (!MSECCFG_MML_ISSET(env)) { + /* + * If mseccfg.MML Bit is not set, do pmp priv check + * This will always apply to regular PMP. + */ + *allowed_privs = PMP_READ | PMP_WRITE | PMP_EXEC; + if ((mode != PRV_M) || pmp_is_locked(env, i)) { + *allowed_privs &= env->pmp_state.pmp[i].cfg_reg; + } + } else { + /* + * If mseccfg.MML Bit set, do the enhanced pmp priv check + */ + if (mode == PRV_M) { + switch (epmp_operation) { + case 0: + case 1: + case 4: + case 5: + case 6: + case 7: + case 8: + *allowed_privs = 0; + break; + case 2: + case 3: + case 14: + *allowed_privs = PMP_READ | PMP_WRITE; + break; + case 9: + case 10: + *allowed_privs = PMP_EXEC; + break; + case 11: + case 13: + *allowed_privs = PMP_READ | PMP_EXEC; + break; + case 12: + case 15: + *allowed_privs = PMP_READ; + break; + } + } else { + switch (epmp_operation) { + case 0: + case 8: + case 9: + case 12: + case 13: + case 14: + *allowed_privs = 0; + break; + case 1: + case 10: + case 11: + *allowed_privs = PMP_EXEC; + break; + case 2: + case 4: + case 15: + *allowed_privs = PMP_READ; + break; + case 3: + case 6: + *allowed_privs = PMP_READ | PMP_WRITE; + break; + case 5: + *allowed_privs = PMP_READ | PMP_EXEC; + break; + case 7: + *allowed_privs = PMP_READ | PMP_WRITE | PMP_EXEC; + break; + } + } } ret = ((privs & *allowed_privs) == privs); @@ -328,10 +467,12 @@ void pmpcfg_csr_write(CPURISCVState *env, uint32_t reg_index, trace_pmpcfg_csr_write(env->mhartid, reg_index, val); - if ((reg_index & 1) && (sizeof(target_ulong) == 8)) { - qemu_log_mask(LOG_GUEST_ERROR, - "ignoring pmpcfg write - incorrect address\n"); - return; + if (!riscv_feature(env, RISCV_FEATURE_EPMP) || !MSECCFG_RLB_ISSET(env)) { + if ((reg_index & 1) && (sizeof(target_ulong) == 8)) { + qemu_log_mask(LOG_GUEST_ERROR, + "ignoring pmpcfg write - incorrect address\n"); + return; + } } for (i = 0; i < sizeof(target_ulong); i++) { -- 2.31.0
