The Ssdbltrp extension allows handling trap when being in non-reentrant state (mainly during exception handling) for S-mode [1]. This patch add support for this extension as an experimental extension.
Link: https://github.com/riscv/riscv-double-trap/releases/download/v0.56/riscv-double-trap.pdf [1] Signed-off-by: Clément Léger <cle...@rivosinc.com> --- target/riscv/cpu.c | 4 ++- target/riscv/cpu.h | 1 + target/riscv/cpu_bits.h | 7 +++++ target/riscv/cpu_cfg.h | 1 + target/riscv/cpu_helper.c | 60 ++++++++++++++++++++++++++++++++++----- target/riscv/csr.c | 44 +++++++++++++++++++++------- target/riscv/op_helper.c | 11 +++++++ 7 files changed, 110 insertions(+), 18 deletions(-) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 36e3e5fdaf..d159b0c6b6 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -182,6 +182,7 @@ const RISCVIsaExtData isa_edata_arr[] = { ISA_EXT_DATA_ENTRY(ssccptr, PRIV_VERSION_1_11_0, has_priv_1_11), ISA_EXT_DATA_ENTRY(sscofpmf, PRIV_VERSION_1_12_0, ext_sscofpmf), ISA_EXT_DATA_ENTRY(sscounterenw, PRIV_VERSION_1_12_0, has_priv_1_12), + ISA_EXT_DATA_ENTRY(ssdbltrp, PRIV_VERSION_1_12_0, ext_ssdbltrp), ISA_EXT_DATA_ENTRY(sstc, PRIV_VERSION_1_12_0, ext_sstc), ISA_EXT_DATA_ENTRY(sstvala, PRIV_VERSION_1_12_0, has_priv_1_12), ISA_EXT_DATA_ENTRY(sstvecd, PRIV_VERSION_1_12_0, has_priv_1_12), @@ -276,7 +277,7 @@ static const char * const riscv_excp_names[] = { "load_page_fault", "reserved", "store_page_fault", - "reserved", + "double_trap", "reserved", "reserved", "reserved", @@ -1572,6 +1573,7 @@ const RISCVCPUMultiExtConfig riscv_cpu_vendor_exts[] = { /* These are experimental so mark with 'x-' */ const RISCVCPUMultiExtConfig riscv_cpu_experimental_exts[] = { + MULTI_EXT_CFG_BOOL("x-ssdbltrp", ext_ssdbltrp, false), DEFINE_PROP_END_OF_LIST(), }; diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 3b1a02b944..14f83d4f05 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -505,6 +505,7 @@ void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen); bool riscv_cpu_vector_enabled(CPURISCVState *env); void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable); int riscv_env_mmu_index(CPURISCVState *env, bool ifetch); +bool riscv_env_smode_dbltrp_enabled(CPURISCVState *env); G_NORETURN void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr, MMUAccessType access_type, int mmu_idx, uintptr_t retaddr); diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h index 9ade72ff31..494a036f6e 100644 --- a/target/riscv/cpu_bits.h +++ b/target/riscv/cpu_bits.h @@ -542,6 +542,7 @@ #define MSTATUS_TVM 0x00100000 /* since: priv-1.10 */ #define MSTATUS_TW 0x00200000 /* since: priv-1.10 */ #define MSTATUS_TSR 0x00400000 /* since: priv-1.10 */ +#define MSTATUS_SDT 0x01000000 /* Ssdbltrp extension */ #define MSTATUS_GVA 0x4000000000ULL #define MSTATUS_MPV 0x8000000000ULL @@ -572,6 +573,7 @@ typedef enum { #define SSTATUS_XS 0x00018000 #define SSTATUS_SUM 0x00040000 /* since: priv-1.10 */ #define SSTATUS_MXR 0x00080000 +#define SSTATUS_SDT 0x01000000 /* Ssdbltrp extension */ #define SSTATUS64_UXL 0x0000000300000000ULL @@ -670,6 +672,7 @@ typedef enum RISCVException { RISCV_EXCP_INST_PAGE_FAULT = 0xc, /* since: priv-1.10.0 */ RISCV_EXCP_LOAD_PAGE_FAULT = 0xd, /* since: priv-1.10.0 */ RISCV_EXCP_STORE_PAGE_FAULT = 0xf, /* since: priv-1.10.0 */ + RISCV_EXCP_DOUBLE_TRAP = 0x10, /* Ssdbltrp extension */ RISCV_EXCP_SEMIHOST = 0x11, RISCV_EXCP_INST_GUEST_PAGE_FAULT = 0x14, RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT = 0x15, @@ -744,11 +747,13 @@ typedef enum RISCVException { #define MENVCFG_CBIE (3UL << 4) #define MENVCFG_CBCFE BIT(6) #define MENVCFG_CBZE BIT(7) +#define MENVCFG_DTE (1ULL << 59) /* Ssdbltrp extension */ #define MENVCFG_ADUE (1ULL << 61) #define MENVCFG_PBMTE (1ULL << 62) #define MENVCFG_STCE (1ULL << 63) /* For RV32 */ +#define MENVCFGH_DTE BIT(27) /* Ssdbltrp extension */ #define MENVCFGH_ADUE BIT(29) #define MENVCFGH_PBMTE BIT(30) #define MENVCFGH_STCE BIT(31) @@ -762,11 +767,13 @@ typedef enum RISCVException { #define HENVCFG_CBIE MENVCFG_CBIE #define HENVCFG_CBCFE MENVCFG_CBCFE #define HENVCFG_CBZE MENVCFG_CBZE +#define HENVCFG_DTE MENVCFG_DTE #define HENVCFG_ADUE MENVCFG_ADUE #define HENVCFG_PBMTE MENVCFG_PBMTE #define HENVCFG_STCE MENVCFG_STCE /* For RV32 */ +#define HENVCFGH_DTE MENVCFGH_DTE #define HENVCFGH_ADUE MENVCFGH_ADUE #define HENVCFGH_PBMTE MENVCFGH_PBMTE #define HENVCFGH_STCE MENVCFGH_STCE diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h index cb750154bd..a149c08167 100644 --- a/target/riscv/cpu_cfg.h +++ b/target/riscv/cpu_cfg.h @@ -74,6 +74,7 @@ struct RISCVCPUConfig { bool ext_ztso; bool ext_smstateen; bool ext_sstc; + bool ext_ssdbltrp; bool ext_svadu; bool ext_svinval; bool ext_svnapot; diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index fc090d729a..3d747e5bfc 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -62,6 +62,15 @@ int riscv_env_mmu_index(CPURISCVState *env, bool ifetch) #endif } +bool riscv_env_smode_dbltrp_enabled(CPURISCVState *env) +{ + if (env->virt_enabled) { + return (env->henvcfg & HENVCFG_DTE) != 0; + } else { + return (env->menvcfg & MENVCFG_DTE) != 0; + } +} + void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc, uint64_t *cs_base, uint32_t *pflags) { @@ -544,7 +553,12 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env) mstatus_mask |= MSTATUS_FS; } bool current_virt = env->virt_enabled; + uint64_t dte = current_virt ? env->menvcfg & MENVCFG_DTE : + env->henvcfg & HENVCFG_DTE; + if (riscv_cpu_cfg(env)->ext_ssdbltrp && dte) { + mstatus_mask |= MSTATUS_SDT; + } g_assert(riscv_has_ext(env, RVH)); if (current_virt) { @@ -1648,7 +1662,10 @@ void riscv_cpu_do_interrupt(CPUState *cs) RISCVCPU *cpu = RISCV_CPU(cs); CPURISCVState *env = &cpu->env; + const RISCVCPUConfig *cfg = riscv_cpu_cfg(env); bool write_gva = false; + bool smode_exception; + bool vsmode_exception; uint64_t s; /* @@ -1662,6 +1679,8 @@ void riscv_cpu_do_interrupt(CPUState *cs) !(env->mip & (1 << cause)); bool vs_injected = env->hvip & (1 << cause) & env->hvien && !(env->mip & (1 << cause)); + bool smode_double_trap = false; + uint64_t hdeleg = async ? env->hideleg : env->hedeleg; target_ulong tval = 0; target_ulong tinst = 0; target_ulong htval = 0; @@ -1750,14 +1769,33 @@ void riscv_cpu_do_interrupt(CPUState *cs) __func__, env->mhartid, async, cause, env->pc, tval, riscv_cpu_get_trap_name(cause, async)); - if (env->priv <= PRV_S && cause < 64 && - (((deleg >> cause) & 1) || s_injected || vs_injected)) { - /* handle the trap in S-mode */ + smode_exception = env->priv <= PRV_S && cause < 64 && + (((deleg >> cause) & 1) || s_injected || vs_injected); + vsmode_exception = env->virt_enabled && + (((hdeleg >> cause) & 1) || vs_injected); + /* Check S-mode double trap condition */ + if (cfg->ext_ssdbltrp && smode_exception) { + uint64_t dte = env->menvcfg & MENVCFG_DTE; if (riscv_has_ext(env, RVH)) { - uint64_t hdeleg = async ? env->hideleg : env->hedeleg; + if (vsmode_exception) { + /* Trap to VS mode, use henvcfg instead of menvcfg*/ + dte = env->henvcfg & HENVCFG_DTE; + } else if (env->virt_enabled) { + /* Trap into HS mode, from virt + * We can not have a double trap when switching from one mode to + * another since sret clears the SDT flag, so when trapping in + * S-mode, SDT is cleared + * */ + dte = 0; + } + } + smode_double_trap = dte && (env->mstatus & MSTATUS_SDT); + } - if (env->virt_enabled && - (((hdeleg >> cause) & 1) || vs_injected)) { + if (smode_exception && !smode_double_trap) { + /* handle the trap in S-mode */ + if (riscv_has_ext(env, RVH)) { + if (vsmode_exception) { /* Trap to VS mode */ /* * See if we need to adjust cause. Yes if its VS mode interrupt @@ -1790,6 +1828,9 @@ void riscv_cpu_do_interrupt(CPUState *cs) s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE)); s = set_field(s, MSTATUS_SPP, env->priv); s = set_field(s, MSTATUS_SIE, 0); + if (riscv_env_smode_dbltrp_enabled(env)) { + s = set_field(s, MSTATUS_SDT, 1); + } env->mstatus = s; env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1)); env->sepc = env->pc; @@ -1823,9 +1864,14 @@ void riscv_cpu_do_interrupt(CPUState *cs) s = set_field(s, MSTATUS_MIE, 0); env->mstatus = s; env->mcause = cause | ~(((target_ulong)-1) >> async); + if (smode_double_trap) { + env->mtval2 = env->mcause; + env->mcause = RISCV_EXCP_DOUBLE_TRAP; + } else { + env->mtval2 = mtval2; + } env->mepc = env->pc; env->mtval = tval; - env->mtval2 = mtval2; env->mtinst = tinst; env->pc = (env->mtvec >> 2 << 2) + ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0); diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 726096444f..1a2e739947 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -514,6 +514,15 @@ static RISCVException aia_hmode32(CPURISCVState *env, int csrno) return hmode32(env, csrno); } +static RISCVException dbltrp_hmode(CPURISCVState *env, int csrno) +{ + if (riscv_cpu_cfg(env)->ext_ssdbltrp) { + return RISCV_EXCP_NONE; + } + + return hmode(env, csrno); +} + static RISCVException pmp(CPURISCVState *env, int csrno) { if (riscv_cpu_cfg(env)->pmp) { @@ -1182,7 +1191,7 @@ static const target_ulong vs_delegable_excps = DELEGABLE_EXCPS & (1ULL << (RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT))); static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE | SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS | - SSTATUS_SUM | SSTATUS_MXR | SSTATUS_VS; + SSTATUS_SUM | SSTATUS_MXR | SSTATUS_VS | SSTATUS_SDT; /* * Spec allows for bits 13:63 to be either read-only or writable. @@ -1380,6 +1389,13 @@ static RISCVException write_mstatus(CPURISCVState *env, int csrno, mask |= MSTATUS_VS; } + if (riscv_env_smode_dbltrp_enabled(env)) { + mask |= MSTATUS_SDT; + if ((val & MSTATUS_SDT) != 0) { + mask &= ~MSTATUS_SIE; + } + } + if (xl != MXL_RV32 || env->debugger) { if (riscv_has_ext(env, RVH)) { mask |= MSTATUS_MPV | MSTATUS_GVA; @@ -2089,7 +2105,8 @@ static RISCVException write_menvcfg(CPURISCVState *env, int csrno, if (riscv_cpu_mxl(env) == MXL_RV64) { mask |= (cfg->ext_svpbmt ? MENVCFG_PBMTE : 0) | (cfg->ext_sstc ? MENVCFG_STCE : 0) | - (cfg->ext_svadu ? MENVCFG_ADUE : 0); + (cfg->ext_svadu ? MENVCFG_ADUE : 0) | + (cfg->ext_ssdbltrp ? MENVCFG_DTE : 0); } env->menvcfg = (env->menvcfg & ~mask) | (val & mask); @@ -2109,7 +2126,8 @@ static RISCVException write_menvcfgh(CPURISCVState *env, int csrno, const RISCVCPUConfig *cfg = riscv_cpu_cfg(env); uint64_t mask = (cfg->ext_svpbmt ? MENVCFG_PBMTE : 0) | (cfg->ext_sstc ? MENVCFG_STCE : 0) | - (cfg->ext_svadu ? MENVCFG_ADUE : 0); + (cfg->ext_svadu ? MENVCFG_ADUE : 0) | + (cfg->ext_ssdbltrp ? MENVCFG_DTE : 0); uint64_t valh = (uint64_t)val << 32; env->menvcfg = (env->menvcfg & ~mask) | (valh & mask); @@ -2160,9 +2178,10 @@ static RISCVException read_henvcfg(CPURISCVState *env, int csrno, * henvcfg.pbmte is read_only 0 when menvcfg.pbmte = 0 * henvcfg.stce is read_only 0 when menvcfg.stce = 0 * henvcfg.adue is read_only 0 when menvcfg.adue = 0 + * henvcfg.dte is read_only 0 when menvcfg.dte = 0 */ - *val = env->henvcfg & (~(HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE) | - env->menvcfg); + *val = env->henvcfg & (~(HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE | + HENVCFG_DTE) | env->menvcfg); return RISCV_EXCP_NONE; } @@ -2170,6 +2189,7 @@ static RISCVException write_henvcfg(CPURISCVState *env, int csrno, target_ulong val) { uint64_t mask = HENVCFG_FIOM | HENVCFG_CBIE | HENVCFG_CBCFE | HENVCFG_CBZE; + uint64_t menvcfg_mask; RISCVException ret; ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG); @@ -2178,7 +2198,11 @@ static RISCVException write_henvcfg(CPURISCVState *env, int csrno, } if (riscv_cpu_mxl(env) == MXL_RV64) { - mask |= env->menvcfg & (HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE); + menvcfg_mask = HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE; + if (riscv_cpu_cfg(env)->ext_ssdbltrp) { + menvcfg_mask |= HENVCFG_DTE; + } + mask |= env->menvcfg & menvcfg_mask; } env->henvcfg = (env->henvcfg & ~mask) | (val & mask); @@ -2196,8 +2220,8 @@ static RISCVException read_henvcfgh(CPURISCVState *env, int csrno, return ret; } - *val = (env->henvcfg & (~(HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE) | - env->menvcfg)) >> 32; + *val = (env->henvcfg & (~(HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE | + HENVCFG_DTE) | env->menvcfg)) >> 32; return RISCV_EXCP_NONE; } @@ -2205,7 +2229,7 @@ static RISCVException write_henvcfgh(CPURISCVState *env, int csrno, target_ulong val) { uint64_t mask = env->menvcfg & (HENVCFG_PBMTE | HENVCFG_STCE | - HENVCFG_ADUE); + HENVCFG_ADUE | HENVCFG_DTE); uint64_t valh = (uint64_t)val << 32; RISCVException ret; @@ -4801,7 +4825,7 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { [CSR_VSATP] = { "vsatp", hmode, read_vsatp, write_vsatp, .min_priv_ver = PRIV_VERSION_1_12_0 }, - [CSR_MTVAL2] = { "mtval2", hmode, read_mtval2, write_mtval2, + [CSR_MTVAL2] = { "mtval2", dbltrp_hmode, read_mtval2, write_mtval2, .min_priv_ver = PRIV_VERSION_1_12_0 }, [CSR_MTINST] = { "mtinst", hmode, read_mtinst, write_mtinst, .min_priv_ver = PRIV_VERSION_1_12_0 }, diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c index f414aaebdb..468ee58a00 100644 --- a/target/riscv/op_helper.c +++ b/target/riscv/op_helper.c @@ -289,6 +289,17 @@ target_ulong helper_sret(CPURISCVState *env) get_field(mstatus, MSTATUS_SPIE)); mstatus = set_field(mstatus, MSTATUS_SPIE, 1); mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U); + if (riscv_cpu_cfg(env)->ext_ssdbltrp) { + if (env->virt_enabled) { + if (get_field(env->henvcfg, HENVCFG_DTE)) { + mstatus = set_field(mstatus, MSTATUS_SDT, 0); + } + } else { + if (get_field(env->menvcfg, MENVCFG_DTE)) { + mstatus = set_field(mstatus, MSTATUS_SDT, 0); + } + } + } if (env->priv_ver >= PRIV_VERSION_1_12_0) { mstatus = set_field(mstatus, MSTATUS_MPRV, 0); } -- 2.43.0