On Tue, Jan 31, 2023 at 10:36 PM Alexandre Ghiti <alexgh...@rivosinc.com> wrote:
> 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: > - valid_vm_1_10_[32|64] constrains which satp mode the CPU can use > - the CPU hw capabilities constrains what the user may select > - the user's selection then constrains what's available to the guest > OS. > > Signed-off-by: Alexandre Ghiti <alexgh...@rivosinc.com> > Reviewed-by: Andrew Jones <ajo...@ventanamicro.com> > --- > target/riscv/cpu.c | 79 +++++++++++++++++++++++++++++++--------------- > target/riscv/cpu.h | 8 +++-- > 2 files changed, 60 insertions(+), 27 deletions(-) > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index 3a7a1746aa..6dd76355ec 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -292,26 +292,36 @@ 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_map(RISCVCPU *cpu) > +static void set_satp_mode_max_supported(RISCVCPU *cpu, > + uint8_t satp_mode) > { > bool rv32 = riscv_cpu_mxl(&cpu->env) == MXL_RV32; > + const bool *valid_vm = rv32 ? valid_vm_1_10_32 : valid_vm_1_10_64; > This will break user-mode QEMU. valid_vm_1_10_32 and valid_vm_1_10_64 are defined in !CONFIG_USER_ONLY section. This issue also exists in patch 3. You have to move valid_vm_1_10_32 and valid_vm_1_10_64 out from !CONFIG_USER_ONLY. Regards, Frank Chang > - if (riscv_feature(&cpu->env, RISCV_FEATURE_MMU)) { > - cpu->cfg.satp_mode.map |= > - (1 << satp_mode_from_str(rv32 ? "sv32" : "sv57")); > - } else { > - cpu->cfg.satp_mode.map |= (1 << satp_mode_from_str("mbare")); > + for (int i = 0; i <= satp_mode; ++i) { > + if (valid_vm[i]) { > + cpu->cfg.satp_mode.supported |= (1 << i); > + } > } > } > > +/* Set the satp mode to the max supported */ > +static void set_satp_mode_default_map(RISCVCPU *cpu) > +{ > + cpu->cfg.satp_mode.map = cpu->cfg.satp_mode.supported; > +} > + > 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, VM_1_10_SV32); > #elif defined(TARGET_RISCV64) > set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVU); > + set_satp_mode_max_supported(cpu, VM_1_10_SV57); > #endif > set_priv_version(env, PRIV_VERSION_1_12_0); > register_cpu_props(obj); > @@ -321,18 +331,24 @@ 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, VM_1_10_SV57); > } > > 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, VM_1_10_SV39); > } > > static void rv64_sifive_e_cpu_init(Object *obj) > @@ -343,6 +359,7 @@ 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, VM_1_10_MBARE); > } > > static void rv128_base_cpu_init(Object *obj) > @@ -354,28 +371,36 @@ 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, VM_1_10_SV57); > } > #else > static void rv32_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_RV32, 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, VM_1_10_SV32); > } > > 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, VM_1_10_SV32); > } > > static void rv32_sifive_e_cpu_init(Object *obj) > @@ -386,6 +411,7 @@ 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, VM_1_10_MBARE); > } > > static void rv32_ibex_cpu_init(Object *obj) > @@ -396,6 +422,7 @@ 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, VM_1_10_MBARE); > cpu->cfg.epmp = true; > } > > @@ -407,6 +434,7 @@ 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, VM_1_10_MBARE); > } > #endif > > @@ -698,8 +726,9 @@ 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_max; > + uint8_t satp_mode_map_max; > + uint8_t satp_mode_supported_max = > + > satp_mode_max_from_map(cpu->cfg.satp_mode.supported); > > if (cpu->cfg.satp_mode.map == 0) { > if (cpu->cfg.satp_mode.init == 0) { > @@ -712,9 +741,10 @@ static void riscv_cpu_satp_mode_finalize(RISCVCPU > *cpu, Error **errp) > * valid_vm_1_10_32/64. > */ > for (int i = 1; i < 16; ++i) { > - if ((cpu->cfg.satp_mode.init & (1 << i)) && valid_vm[i]) { > + if ((cpu->cfg.satp_mode.init & (1 << 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; > } > @@ -725,37 +755,36 @@ 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; > - } > + satp_mode_map_max = satp_mode_max_from_map(cpu->cfg.satp_mode.map); > + > + /* 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; > } > > /* > * Make sure the user did not ask for an invalid configuration as per > * the specification. > */ > - satp_mode_max = satp_mode_max_from_map(cpu->cfg.satp_mode.map); > - > if (!rv32) { > - 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; > } > } > } > > /* Finally expand the map so that all valid modes are set */ > - for (int i = satp_mode_max - 1; i >= 0; --i) { > - if (valid_vm[i]) { > + for (int i = satp_mode_map_max - 1; i >= 0; --i) { > + if (cpu->cfg.satp_mode.supported & (1 << i)) { > cpu->cfg.satp_mode.map |= (1 << i); > } > } > 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 > > >