From f2f68a78b793808b84367bc708d632969d4440aa Mon Sep 17 00:00:00 2001 From: Rebecca Cran Date: Tue, 16 Feb 2021 15:45:41 -0700 Subject: [PATCH] target/arm: Add support for FEAT_SSBS, Speculative Store Bypass Safe Add support for FEAT_SSBS. SSBS (Speculative Store Bypass Safe) is an optional feature in ARMv8.0, and mandatory in ARMv8.5. Signed-off-by: Rebecca Cran Reviewed-by: Richard Henderson Message-id: 20210216224543.16142-2-rebecca@nuviainc.com Signed-off-by: Peter Maydell --- target/arm/cpu.h | 15 ++++++++++++++- target/arm/helper.c | 37 +++++++++++++++++++++++++++++++++++++ target/arm/internals.h | 6 ++++++ target/arm/translate-a64.c | 12 ++++++++++++ 4 files changed, 69 insertions(+), 1 deletion(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index efa1618c4d..193a49ec7f 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1206,6 +1206,7 @@ void pmu_init(ARMCPU *cpu); #define SCTLR_TE (1U << 30) /* AArch32 only */ #define SCTLR_EnIB (1U << 30) /* v8.3, AArch64 only */ #define SCTLR_EnIA (1U << 31) /* v8.3, AArch64 only */ +#define SCTLR_DSSBS_32 (1U << 31) /* v8.5, AArch32 only */ #define SCTLR_BT0 (1ULL << 35) /* v8.5-BTI */ #define SCTLR_BT1 (1ULL << 36) /* v8.5-BTI */ #define SCTLR_ITFSB (1ULL << 37) /* v8.5-MemTag */ @@ -1213,7 +1214,7 @@ void pmu_init(ARMCPU *cpu); #define SCTLR_TCF (3ULL << 40) /* v8.5-MemTag */ #define SCTLR_ATA0 (1ULL << 42) /* v8.5-MemTag */ #define SCTLR_ATA (1ULL << 43) /* v8.5-MemTag */ -#define SCTLR_DSSBS (1ULL << 44) /* v8.5 */ +#define SCTLR_DSSBS_64 (1ULL << 44) /* v8.5, AArch64 only */ #define CPTR_TCPAC (1U << 31) #define CPTR_TTA (1U << 20) @@ -1250,6 +1251,7 @@ void pmu_init(ARMCPU *cpu); #define CPSR_IL (1U << 20) #define CPSR_DIT (1U << 21) #define CPSR_PAN (1U << 22) +#define CPSR_SSBS (1U << 23) #define CPSR_J (1U << 24) #define CPSR_IT_0_1 (3U << 25) #define CPSR_Q (1U << 27) @@ -1312,6 +1314,7 @@ void pmu_init(ARMCPU *cpu); #define PSTATE_A (1U << 8) #define PSTATE_D (1U << 9) #define PSTATE_BTYPE (3U << 10) +#define PSTATE_SSBS (1U << 12) #define PSTATE_IL (1U << 20) #define PSTATE_SS (1U << 21) #define PSTATE_PAN (1U << 22) @@ -3915,6 +3918,11 @@ static inline bool isar_feature_aa32_dit(const ARMISARegisters *id) return FIELD_EX32(id->id_pfr0, ID_PFR0, DIT) != 0; } +static inline bool isar_feature_aa32_ssbs(const ARMISARegisters *id) +{ + return FIELD_EX32(id->id_pfr2, ID_PFR2, SSBS) != 0; +} + /* * 64-bit feature tests via id registers. */ @@ -4169,6 +4177,11 @@ static inline bool isar_feature_aa64_dit(const ARMISARegisters *id) return FIELD_EX64(id->id_aa64pfr0, ID_AA64PFR0, DIT) != 0; } +static inline bool isar_feature_aa64_ssbs(const ARMISARegisters *id) +{ + return FIELD_EX64(id->id_aa64pfr1, ID_AA64PFR1, SSBS) != 0; +} + /* * Feature tests for "does this exist in either 32-bit or 64-bit?" */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 0e1a3b9421..fedcf2e739 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -4450,6 +4450,24 @@ static const ARMCPRegInfo dit_reginfo = { .readfn = aa64_dit_read, .writefn = aa64_dit_write }; +static uint64_t aa64_ssbs_read(CPUARMState *env, const ARMCPRegInfo *ri) +{ + return env->pstate & PSTATE_SSBS; +} + +static void aa64_ssbs_write(CPUARMState *env, const ARMCPRegInfo *ri, + uint64_t value) +{ + env->pstate = (env->pstate & ~PSTATE_SSBS) | (value & PSTATE_SSBS); +} + +static const ARMCPRegInfo ssbs_reginfo = { + .name = "SSBS", .state = ARM_CP_STATE_AA64, + .opc0 = 3, .opc1 = 3, .crn = 4, .crm = 2, .opc2 = 6, + .type = ARM_CP_NO_RAW, .access = PL0_RW, + .readfn = aa64_ssbs_read, .writefn = aa64_ssbs_write +}; + static CPAccessResult aa64_cacheop_poc_access(CPUARMState *env, const ARMCPRegInfo *ri, bool isread) @@ -8244,6 +8262,9 @@ void register_cp_regs_for_features(ARMCPU *cpu) if (cpu_isar_feature(aa64_dit, cpu)) { define_one_arm_cp_reg(cpu, &dit_reginfo); } + if (cpu_isar_feature(aa64_ssbs, cpu)) { + define_one_arm_cp_reg(cpu, &ssbs_reginfo); + } if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) { define_arm_cp_regs(cpu, vhe_reginfo); @@ -9463,6 +9484,14 @@ static void take_aarch32_exception(CPUARMState *env, int new_mode, env->uncached_cpsr &= ~(CPSR_IL | CPSR_J); env->daif |= mask; + if (cpu_isar_feature(aa32_ssbs, env_archcpu(env))) { + if (env->cp15.sctlr_el[new_el] & SCTLR_DSSBS_32) { + env->uncached_cpsr |= CPSR_SSBS; + } else { + env->uncached_cpsr &= ~CPSR_SSBS; + } + } + if (new_mode == ARM_CPU_MODE_HYP) { env->thumb = (env->cp15.sctlr_el[2] & SCTLR_TE) != 0; env->elr_el[2] = env->regs[15]; @@ -9973,6 +10002,14 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs) new_mode |= PSTATE_TCO; } + if (cpu_isar_feature(aa64_ssbs, cpu)) { + if (env->cp15.sctlr_el[new_el] & SCTLR_DSSBS_64) { + new_mode |= PSTATE_SSBS; + } else { + new_mode &= ~PSTATE_SSBS; + } + } + pstate_write(env, PSTATE_DAIF | new_mode); env->aarch64 = 1; aarch64_restore_sp(env, new_el); diff --git a/target/arm/internals.h b/target/arm/internals.h index 05cebc8597..f11bd32696 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -987,6 +987,9 @@ static inline uint32_t aarch32_cpsr_valid_mask(uint64_t features, if (isar_feature_aa32_dit(id)) { valid |= CPSR_DIT; } + if (isar_feature_aa32_ssbs(id)) { + valid |= CPSR_SSBS; + } return valid; } @@ -1008,6 +1011,9 @@ static inline uint32_t aarch64_pstate_valid_mask(const ARMISARegisters *id) if (isar_feature_aa64_dit(id)) { valid |= PSTATE_DIT; } + if (isar_feature_aa64_ssbs(id)) { + valid |= PSTATE_SSBS; + } if (isar_feature_aa64_mte(id)) { valid |= PSTATE_TCO; } diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index b23a8975d5..3aebdb4af9 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1703,6 +1703,18 @@ static void handle_msr_i(DisasContext *s, uint32_t insn, tcg_temp_free_i32(t1); break; + case 0x19: /* SSBS */ + if (!dc_isar_feature(aa64_ssbs, s)) { + goto do_unallocated; + } + if (crm & 1) { + set_pstate_bits(PSTATE_SSBS); + } else { + clear_pstate_bits(PSTATE_SSBS); + } + /* Don't need to rebuild hflags since SSBS is a nop */ + break; + case 0x1a: /* DIT */ if (!dc_isar_feature(aa64_dit, s)) { goto do_unallocated;