Currently, the max satp mode is set with the only constraint that it must be implemented in qemu, i.e. set in valid_vm_1_10_[32|64].
But we actually need to add another level of constraint: what the hw is actually capable of, because currently, a linux booting on a sifive-u54 boots in sv57 mode which is incompatible with the cpu's sv39 max capability. So add a new bitmap to RISCVSATPMap which contains this capability and initialize it in every XXX_cpu_init. Finally, we have the following chain of constraints: Qemu capability > HW capability > User choice > Software capability Signed-off-by: Alexandre Ghiti <alexgh...@rivosinc.com> --- target/riscv/cpu.c | 78 +++++++++++++++++++++++++++++++--------------- target/riscv/cpu.h | 8 +++-- 2 files changed, 59 insertions(+), 27 deletions(-) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index e409e6ab64..19a37fee2b 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -292,24 +292,39 @@ const char *satp_mode_str(uint8_t satp_mode, bool is_32_bit) g_assert_not_reached(); } -/* Sets the satp mode to the max supported */ -static void set_satp_mode_default(RISCVCPU *cpu, bool is_32_bit) +static void set_satp_mode_max_supported(RISCVCPU *cpu, + const char *satp_mode_str, + bool is_32_bit) { - if (riscv_feature(&cpu->env, RISCV_FEATURE_MMU)) { - cpu->cfg.satp_mode.map |= - (1 << satp_mode_from_str(is_32_bit ? "sv32" : "sv57")); - } else { - cpu->cfg.satp_mode.map |= (1 << satp_mode_from_str("mbare")); + uint8_t satp_mode = satp_mode_from_str(satp_mode_str); + const bool *valid_vm = is_32_bit ? valid_vm_1_10_32 : valid_vm_1_10_64; + + for (int i = 0; i <= satp_mode; ++i) { + if (valid_vm[i]) { + cpu->cfg.satp_mode.supported |= (1 << i); + } } } +/* Sets the satp mode to the max supported */ +static void set_satp_mode_default(RISCVCPU *cpu) +{ + uint8_t satp_mode = satp_mode_max_from_map(cpu->cfg.satp_mode.supported); + + cpu->cfg.satp_mode.map |= (1 << satp_mode); +} + static void riscv_any_cpu_init(Object *obj) { CPURISCVState *env = &RISCV_CPU(obj)->env; + RISCVCPU *cpu = RISCV_CPU(obj); + #if defined(TARGET_RISCV32) set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVU); + set_satp_mode_max_supported(cpu, "sv32", true); #elif defined(TARGET_RISCV64) set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVU); + set_satp_mode_max_supported(cpu, "sv57", false); #endif set_priv_version(env, PRIV_VERSION_1_12_0); register_cpu_props(obj); @@ -319,18 +334,24 @@ static void riscv_any_cpu_init(Object *obj) static void rv64_base_cpu_init(Object *obj) { CPURISCVState *env = &RISCV_CPU(obj)->env; + RISCVCPU *cpu = RISCV_CPU(obj); + /* We set this in the realise function */ set_misa(env, MXL_RV64, 0); register_cpu_props(obj); /* Set latest version of privileged specification */ set_priv_version(env, PRIV_VERSION_1_12_0); + set_satp_mode_max_supported(cpu, "sv57", false); } static void rv64_sifive_u_cpu_init(Object *obj) { CPURISCVState *env = &RISCV_CPU(obj)->env; + RISCVCPU *cpu = RISCV_CPU(obj); + set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU); set_priv_version(env, PRIV_VERSION_1_10_0); + set_satp_mode_max_supported(cpu, "sv39", false); } static void rv64_sifive_e_cpu_init(Object *obj) @@ -341,6 +362,7 @@ static void rv64_sifive_e_cpu_init(Object *obj) set_misa(env, MXL_RV64, RVI | RVM | RVA | RVC | RVU); set_priv_version(env, PRIV_VERSION_1_10_0); cpu->cfg.mmu = false; + set_satp_mode_max_supported(cpu, "mbare", false); } static void rv128_base_cpu_init(Object *obj) @@ -352,11 +374,13 @@ static void rv128_base_cpu_init(Object *obj) exit(EXIT_FAILURE); } CPURISCVState *env = &RISCV_CPU(obj)->env; + RISCVCPU *cpu = RISCV_CPU(obj); /* We set this in the realise function */ set_misa(env, MXL_RV128, 0); register_cpu_props(obj); /* Set latest version of privileged specification */ set_priv_version(env, PRIV_VERSION_1_12_0); + set_satp_mode_max_supported(cpu, "sv57", false); } #else static void rv32_base_cpu_init(Object *obj) @@ -367,13 +391,17 @@ static void rv32_base_cpu_init(Object *obj) register_cpu_props(obj); /* Set latest version of privileged specification */ set_priv_version(env, PRIV_VERSION_1_12_0); + set_satp_mode_max_supported(cpu, "sv32", true); } static void rv32_sifive_u_cpu_init(Object *obj) { CPURISCVState *env = &RISCV_CPU(obj)->env; + RISCVCPU *cpu = RISCV_CPU(obj); + set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU); set_priv_version(env, PRIV_VERSION_1_10_0); + set_satp_mode_max_supported(cpu, "sv32", true); } static void rv32_sifive_e_cpu_init(Object *obj) @@ -384,6 +412,7 @@ static void rv32_sifive_e_cpu_init(Object *obj) set_misa(env, MXL_RV32, RVI | RVM | RVA | RVC | RVU); set_priv_version(env, PRIV_VERSION_1_10_0); cpu->cfg.mmu = false; + set_satp_mode_max_supported(cpu, "mbare", true); } static void rv32_ibex_cpu_init(Object *obj) @@ -394,6 +423,7 @@ static void rv32_ibex_cpu_init(Object *obj) set_misa(env, MXL_RV32, RVI | RVM | RVC | RVU); set_priv_version(env, PRIV_VERSION_1_11_0); cpu->cfg.mmu = false; + set_satp_mode_max_supported(cpu, "mbare", true); cpu->cfg.epmp = true; } @@ -405,6 +435,7 @@ static void rv32_imafcu_nommu_cpu_init(Object *obj) set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVC | RVU); set_priv_version(env, PRIV_VERSION_1_10_0); cpu->cfg.mmu = false; + set_satp_mode_max_supported(cpu, "mbare", true); } #endif @@ -696,7 +727,9 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info) static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp) { bool rv32 = riscv_cpu_mxl(&cpu->env) == MXL_RV32; - const bool *valid_vm = rv32 ? valid_vm_1_10_32 : valid_vm_1_10_64; + uint8_t satp_mode_map_max = satp_mode_max_from_map(cpu->cfg.satp_mode.map); + uint8_t satp_mode_supported_max = + satp_mode_max_from_map(cpu->cfg.satp_mode.supported); if (cpu->cfg.satp_mode.map == 0) { /* @@ -704,7 +737,7 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp) * satp mode. */ if (cpu->cfg.satp_mode.init == 0) { - set_satp_mode_default(cpu, rv32); + set_satp_mode_default(cpu); } else { /* * Find the lowest level that was disabled and then enable the @@ -714,9 +747,9 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp) for (int i = 1; i < 16; ++i) { if (!(cpu->cfg.satp_mode.map & (1 << i)) && (cpu->cfg.satp_mode.init & (1 << i)) && - valid_vm[i]) { + (cpu->cfg.satp_mode.supported & (1 << i))) { for (int j = i - 1; j >= 0; --j) { - if (valid_vm[j]) { + if (cpu->cfg.satp_mode.supported & (1 << j)) { cpu->cfg.satp_mode.map |= (1 << j); break; } @@ -727,13 +760,12 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp) } } - /* Make sure the configuration asked is supported by qemu */ - for (int i = 0; i < 16; ++i) { - if ((cpu->cfg.satp_mode.map & (1 << i)) && !valid_vm[i]) { - error_setg(errp, "satp_mode %s is not valid", - satp_mode_str(i, rv32)); - return; - } + /* Make sure the user asked for a supported configuration (HW and qemu) */ + if (satp_mode_map_max > satp_mode_supported_max) { + error_setg(errp, "satp_mode %s is higher than hw max capability %s", + satp_mode_str(satp_mode_map_max, rv32), + satp_mode_str(satp_mode_supported_max, rv32)); + return; } /* @@ -741,17 +773,13 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU *cpu, Error **errp) * the specification. */ if (!rv32) { - uint8_t satp_mode_max; - - satp_mode_max = satp_mode_max_from_map(cpu->cfg.satp_mode.map); - - for (int i = satp_mode_max - 1; i >= 0; --i) { + for (int i = satp_mode_map_max - 1; i >= 0; --i) { if (!(cpu->cfg.satp_mode.map & (1 << i)) && (cpu->cfg.satp_mode.init & (1 << i)) && - valid_vm[i]) { + (cpu->cfg.satp_mode.supported & (1 << i))) { error_setg(errp, "cannot disable %s satp mode if %s " "is enabled", satp_mode_str(i, false), - satp_mode_str(satp_mode_max, false)); + satp_mode_str(satp_mode_map_max, false)); return; } } diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index e37177db5c..b591122099 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -416,13 +416,17 @@ struct RISCVCPUClass { /* * map is a 16-bit bitmap: the most significant set bit in map is the maximum - * satp mode that is supported. + * satp mode that is supported. It may be chosen by the user and must respect + * what qemu implements (valid_1_10_32/64) and what the hw is capable of + * (supported bitmap below). * * init is a 16-bit bitmap used to make sure the user selected a correct * configuration as per the specification. + * + * supported is a 16-bit bitmap used to reflect the hw capabilities. */ typedef struct { - uint16_t map, init; + uint16_t map, init, supported; } RISCVSATPMap; struct RISCVCPUConfig { -- 2.37.2