diff options
Diffstat (limited to 'target/riscv/pmp.c')
| -rw-r--r-- | target/riscv/pmp.c | 218 |
1 files changed, 196 insertions, 22 deletions
diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index cff020122a..78203291de 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -19,10 +19,6 @@ * this program. If not, see <http://www.gnu.org/licenses/>. */ -/* - * PMP (Physical Memory Protection) is as-of-yet unused and needs testing. - */ - #include "qemu/osdep.h" #include "qemu/log.h" #include "qapi/error.h" @@ -59,16 +55,6 @@ static inline int pmp_is_locked(CPURISCVState *env, uint32_t pmp_index) return 0; } - /* In TOR mode, need to check the lock bit of the next pmp - * (if there is a next) - */ - const uint8_t a_field = - pmp_get_a_field(env->pmp_state.pmp[pmp_index + 1].cfg_reg); - if ((env->pmp_state.pmp[pmp_index + 1u].cfg_reg & PMP_LOCK) && - (PMP_AMATCH_TOR == a_field)) { - return 1; - } - return 0; } @@ -100,11 +86,42 @@ 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, @@ -227,6 +244,32 @@ 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 @@ -304,13 +347,94 @@ 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); @@ -380,7 +504,23 @@ void pmpaddr_csr_write(CPURISCVState *env, uint32_t addr_index, target_ulong val) { trace_pmpaddr_csr_write(env->mhartid, addr_index, val); + if (addr_index < MAX_RISCV_PMPS) { + /* + * In TOR mode, need to check the lock bit of the next pmp + * (if there is a next). + */ + if (addr_index + 1 < MAX_RISCV_PMPS) { + uint8_t pmp_cfg = env->pmp_state.pmp[addr_index + 1].cfg_reg; + + if (pmp_cfg & PMP_LOCK && + PMP_AMATCH_TOR == pmp_get_a_field(pmp_cfg)) { + qemu_log_mask(LOG_GUEST_ERROR, + "ignoring pmpaddr write - pmpcfg + 1 locked\n"); + return; + } + } + if (!pmp_is_locked(env, addr_index)) { env->pmp_state.pmp[addr_index].addr_reg = val; pmp_update_rule(env, addr_index); @@ -414,6 +554,40 @@ target_ulong pmpaddr_csr_read(CPURISCVState *env, uint32_t addr_index) } /* + * Handle a write to a mseccfg CSR + */ +void mseccfg_csr_write(CPURISCVState *env, target_ulong val) +{ + int i; + + trace_mseccfg_csr_write(env->mhartid, val); + + /* RLB cannot be enabled if it's already 0 and if any regions are locked */ + if (!MSECCFG_RLB_ISSET(env)) { + for (i = 0; i < MAX_RISCV_PMPS; i++) { + if (pmp_is_locked(env, i)) { + val &= ~MSECCFG_RLB; + break; + } + } + } + + /* Sticky bits */ + val |= (env->mseccfg & (MSECCFG_MMWP | MSECCFG_MML)); + + env->mseccfg = val; +} + +/* + * Handle a read from a mseccfg CSR + */ +target_ulong mseccfg_csr_read(CPURISCVState *env) +{ + trace_mseccfg_csr_read(env->mhartid, env->mseccfg); + return env->mseccfg; +} + +/* * Calculate the TLB size if the start address or the end address of * PMP entry is presented in thie TLB page. */ |