From b93777e1b4999b1f51f1fa3398f5d400f75a4aab Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Sat, 16 Jan 2021 13:41:22 +0800 Subject: [PATCH] target/riscv: Generate the GDB XML file for CSR registers dynamically At present QEMU RISC-V uses a hardcoded XML to report the feature "org.gnu.gdb.riscv.csr" [1]. There are two major issues with the approach being used currently: - The XML does not specify the "regnum" field of a CSR entry, hence consecutive numbers are used by the remote GDB client to access CSRs. In QEMU we have to maintain a map table to convert the GDB number to the hardware number which is error prone. - The XML contains some CSRs that QEMU does not implement at all, which causes an "E14" response sent to remote GDB client. Change to generate the CSR register list dynamically, based on the availability presented in the CSR function table. This new approach will reflect a correct list of CSRs that QEMU actually implements. [1] https://sourceware.org/gdb/current/onlinedocs/gdb/RISC_002dV-Features.html#RISC_002dV-Features Signed-off-by: Bin Meng Reviewed-by: Alistair Francis Message-id: 20210116054123.5457-2-bmeng.cn@gmail.com Signed-off-by: Alistair Francis --- target/riscv/cpu.c | 12 ++ target/riscv/cpu.h | 2 + target/riscv/gdbstub.c | 308 ++++++----------------------------------- 3 files changed, 58 insertions(+), 264 deletions(-) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 6aafe4e62c..27788021eb 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -569,6 +569,17 @@ static gchar *riscv_gdb_arch_name(CPUState *cs) } } +static const char *riscv_gdb_get_dynamic_xml(CPUState *cs, const char *xmlname) +{ + RISCVCPU *cpu = RISCV_CPU(cs); + + if (strcmp(xmlname, "riscv-csr.xml") == 0) { + return cpu->dyn_csr_xml; + } + + return NULL; +} + static void riscv_cpu_class_init(ObjectClass *c, void *data) { RISCVCPUClass *mcc = RISCV_CPU_CLASS(c); @@ -605,6 +616,7 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data) cc->vmsd = &vmstate_riscv_cpu; #endif cc->gdb_arch_name = riscv_gdb_arch_name; + cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml; #ifdef CONFIG_TCG cc->tcg_initialize = riscv_translate_init; cc->tlb_fill = riscv_cpu_tlb_fill; diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 2718617ef4..02758ae0eb 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -272,6 +272,8 @@ struct RISCVCPU { CPUNegativeOffsetState neg; CPURISCVState env; + char *dyn_csr_xml; + /* Configuration Settings */ struct { bool ext_i; diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c index eba12a86f2..5f96b7ea2a 100644 --- a/target/riscv/gdbstub.c +++ b/target/riscv/gdbstub.c @@ -20,256 +20,6 @@ #include "exec/gdbstub.h" #include "cpu.h" -/* - * The GDB CSR xml files list them in documentation order, not numerical order, - * and are missing entries for unnamed CSRs. So we need to map the gdb numbers - * to the hardware numbers. - */ - -static int csr_register_map[] = { - CSR_USTATUS, - CSR_UIE, - CSR_UTVEC, - CSR_USCRATCH, - CSR_UEPC, - CSR_UCAUSE, - CSR_UTVAL, - CSR_UIP, - CSR_FFLAGS, - CSR_FRM, - CSR_FCSR, - CSR_CYCLE, - CSR_TIME, - CSR_INSTRET, - CSR_HPMCOUNTER3, - CSR_HPMCOUNTER4, - CSR_HPMCOUNTER5, - CSR_HPMCOUNTER6, - CSR_HPMCOUNTER7, - CSR_HPMCOUNTER8, - CSR_HPMCOUNTER9, - CSR_HPMCOUNTER10, - CSR_HPMCOUNTER11, - CSR_HPMCOUNTER12, - CSR_HPMCOUNTER13, - CSR_HPMCOUNTER14, - CSR_HPMCOUNTER15, - CSR_HPMCOUNTER16, - CSR_HPMCOUNTER17, - CSR_HPMCOUNTER18, - CSR_HPMCOUNTER19, - CSR_HPMCOUNTER20, - CSR_HPMCOUNTER21, - CSR_HPMCOUNTER22, - CSR_HPMCOUNTER23, - CSR_HPMCOUNTER24, - CSR_HPMCOUNTER25, - CSR_HPMCOUNTER26, - CSR_HPMCOUNTER27, - CSR_HPMCOUNTER28, - CSR_HPMCOUNTER29, - CSR_HPMCOUNTER30, - CSR_HPMCOUNTER31, - CSR_CYCLEH, - CSR_TIMEH, - CSR_INSTRETH, - CSR_HPMCOUNTER3H, - CSR_HPMCOUNTER4H, - CSR_HPMCOUNTER5H, - CSR_HPMCOUNTER6H, - CSR_HPMCOUNTER7H, - CSR_HPMCOUNTER8H, - CSR_HPMCOUNTER9H, - CSR_HPMCOUNTER10H, - CSR_HPMCOUNTER11H, - CSR_HPMCOUNTER12H, - CSR_HPMCOUNTER13H, - CSR_HPMCOUNTER14H, - CSR_HPMCOUNTER15H, - CSR_HPMCOUNTER16H, - CSR_HPMCOUNTER17H, - CSR_HPMCOUNTER18H, - CSR_HPMCOUNTER19H, - CSR_HPMCOUNTER20H, - CSR_HPMCOUNTER21H, - CSR_HPMCOUNTER22H, - CSR_HPMCOUNTER23H, - CSR_HPMCOUNTER24H, - CSR_HPMCOUNTER25H, - CSR_HPMCOUNTER26H, - CSR_HPMCOUNTER27H, - CSR_HPMCOUNTER28H, - CSR_HPMCOUNTER29H, - CSR_HPMCOUNTER30H, - CSR_HPMCOUNTER31H, - CSR_SSTATUS, - CSR_SEDELEG, - CSR_SIDELEG, - CSR_SIE, - CSR_STVEC, - CSR_SCOUNTEREN, - CSR_SSCRATCH, - CSR_SEPC, - CSR_SCAUSE, - CSR_STVAL, - CSR_SIP, - CSR_SATP, - CSR_MVENDORID, - CSR_MARCHID, - CSR_MIMPID, - CSR_MHARTID, - CSR_MSTATUS, - CSR_MISA, - CSR_MEDELEG, - CSR_MIDELEG, - CSR_MIE, - CSR_MTVEC, - CSR_MCOUNTEREN, - CSR_MSCRATCH, - CSR_MEPC, - CSR_MCAUSE, - CSR_MTVAL, - CSR_MIP, - CSR_MTINST, - CSR_MTVAL2, - CSR_PMPCFG0, - CSR_PMPCFG1, - CSR_PMPCFG2, - CSR_PMPCFG3, - CSR_PMPADDR0, - CSR_PMPADDR1, - CSR_PMPADDR2, - CSR_PMPADDR3, - CSR_PMPADDR4, - CSR_PMPADDR5, - CSR_PMPADDR6, - CSR_PMPADDR7, - CSR_PMPADDR8, - CSR_PMPADDR9, - CSR_PMPADDR10, - CSR_PMPADDR11, - CSR_PMPADDR12, - CSR_PMPADDR13, - CSR_PMPADDR14, - CSR_PMPADDR15, - CSR_MCYCLE, - CSR_MINSTRET, - CSR_MHPMCOUNTER3, - CSR_MHPMCOUNTER4, - CSR_MHPMCOUNTER5, - CSR_MHPMCOUNTER6, - CSR_MHPMCOUNTER7, - CSR_MHPMCOUNTER8, - CSR_MHPMCOUNTER9, - CSR_MHPMCOUNTER10, - CSR_MHPMCOUNTER11, - CSR_MHPMCOUNTER12, - CSR_MHPMCOUNTER13, - CSR_MHPMCOUNTER14, - CSR_MHPMCOUNTER15, - CSR_MHPMCOUNTER16, - CSR_MHPMCOUNTER17, - CSR_MHPMCOUNTER18, - CSR_MHPMCOUNTER19, - CSR_MHPMCOUNTER20, - CSR_MHPMCOUNTER21, - CSR_MHPMCOUNTER22, - CSR_MHPMCOUNTER23, - CSR_MHPMCOUNTER24, - CSR_MHPMCOUNTER25, - CSR_MHPMCOUNTER26, - CSR_MHPMCOUNTER27, - CSR_MHPMCOUNTER28, - CSR_MHPMCOUNTER29, - CSR_MHPMCOUNTER30, - CSR_MHPMCOUNTER31, - CSR_MCYCLEH, - CSR_MINSTRETH, - CSR_MHPMCOUNTER3H, - CSR_MHPMCOUNTER4H, - CSR_MHPMCOUNTER5H, - CSR_MHPMCOUNTER6H, - CSR_MHPMCOUNTER7H, - CSR_MHPMCOUNTER8H, - CSR_MHPMCOUNTER9H, - CSR_MHPMCOUNTER10H, - CSR_MHPMCOUNTER11H, - CSR_MHPMCOUNTER12H, - CSR_MHPMCOUNTER13H, - CSR_MHPMCOUNTER14H, - CSR_MHPMCOUNTER15H, - CSR_MHPMCOUNTER16H, - CSR_MHPMCOUNTER17H, - CSR_MHPMCOUNTER18H, - CSR_MHPMCOUNTER19H, - CSR_MHPMCOUNTER20H, - CSR_MHPMCOUNTER21H, - CSR_MHPMCOUNTER22H, - CSR_MHPMCOUNTER23H, - CSR_MHPMCOUNTER24H, - CSR_MHPMCOUNTER25H, - CSR_MHPMCOUNTER26H, - CSR_MHPMCOUNTER27H, - CSR_MHPMCOUNTER28H, - CSR_MHPMCOUNTER29H, - CSR_MHPMCOUNTER30H, - CSR_MHPMCOUNTER31H, - CSR_MHPMEVENT3, - CSR_MHPMEVENT4, - CSR_MHPMEVENT5, - CSR_MHPMEVENT6, - CSR_MHPMEVENT7, - CSR_MHPMEVENT8, - CSR_MHPMEVENT9, - CSR_MHPMEVENT10, - CSR_MHPMEVENT11, - CSR_MHPMEVENT12, - CSR_MHPMEVENT13, - CSR_MHPMEVENT14, - CSR_MHPMEVENT15, - CSR_MHPMEVENT16, - CSR_MHPMEVENT17, - CSR_MHPMEVENT18, - CSR_MHPMEVENT19, - CSR_MHPMEVENT20, - CSR_MHPMEVENT21, - CSR_MHPMEVENT22, - CSR_MHPMEVENT23, - CSR_MHPMEVENT24, - CSR_MHPMEVENT25, - CSR_MHPMEVENT26, - CSR_MHPMEVENT27, - CSR_MHPMEVENT28, - CSR_MHPMEVENT29, - CSR_MHPMEVENT30, - CSR_MHPMEVENT31, - CSR_TSELECT, - CSR_TDATA1, - CSR_TDATA2, - CSR_TDATA3, - CSR_DCSR, - CSR_DPC, - CSR_DSCRATCH, - CSR_HSTATUS, - CSR_HEDELEG, - CSR_HIDELEG, - CSR_HIE, - CSR_HCOUNTEREN, - CSR_HTVAL, - CSR_HIP, - CSR_HTINST, - CSR_HGATP, - CSR_MBASE, - CSR_MBOUND, - CSR_MIBASE, - CSR_MIBOUND, - CSR_MDBASE, - CSR_MDBOUND, - CSR_MUCOUNTEREN, - CSR_MSCOUNTEREN, - CSR_MHCOUNTEREN, -}; - int riscv_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n) { RISCVCPU *cpu = RISCV_CPU(cs); @@ -315,11 +65,11 @@ static int riscv_gdb_get_fpu(CPURISCVState *env, GByteArray *buf, int n) target_ulong val = 0; int result; /* - * CSR_FFLAGS is at index 8 in csr_register, and gdb says it is FP + * CSR_FFLAGS is at index 1 in csr_register, and gdb says it is FP * register 33, so we recalculate the map index. * This also works for CSR_FRM and CSR_FCSR. */ - result = riscv_csrrw_debug(env, n - 33 + csr_register_map[8], &val, + result = riscv_csrrw_debug(env, n - 32, &val, 0, 0); if (result == 0) { return gdb_get_regl(buf, val); @@ -338,11 +88,11 @@ static int riscv_gdb_set_fpu(CPURISCVState *env, uint8_t *mem_buf, int n) target_ulong val = ldtul_p(mem_buf); int result; /* - * CSR_FFLAGS is at index 8 in csr_register, and gdb says it is FP + * CSR_FFLAGS is at index 1 in csr_register, and gdb says it is FP * register 33, so we recalculate the map index. * This also works for CSR_FRM and CSR_FCSR. */ - result = riscv_csrrw_debug(env, n - 33 + csr_register_map[8], NULL, + result = riscv_csrrw_debug(env, n - 32, NULL, val, -1); if (result == 0) { return sizeof(target_ulong); @@ -353,11 +103,11 @@ static int riscv_gdb_set_fpu(CPURISCVState *env, uint8_t *mem_buf, int n) static int riscv_gdb_get_csr(CPURISCVState *env, GByteArray *buf, int n) { - if (n < ARRAY_SIZE(csr_register_map)) { + if (n < CSR_TABLE_SIZE) { target_ulong val = 0; int result; - result = riscv_csrrw_debug(env, csr_register_map[n], &val, 0, 0); + result = riscv_csrrw_debug(env, n, &val, 0, 0); if (result == 0) { return gdb_get_regl(buf, val); } @@ -367,11 +117,11 @@ static int riscv_gdb_get_csr(CPURISCVState *env, GByteArray *buf, int n) static int riscv_gdb_set_csr(CPURISCVState *env, uint8_t *mem_buf, int n) { - if (n < ARRAY_SIZE(csr_register_map)) { + if (n < CSR_TABLE_SIZE) { target_ulong val = ldtul_p(mem_buf); int result; - result = riscv_csrrw_debug(env, csr_register_map[n], NULL, val, -1); + result = riscv_csrrw_debug(env, n, NULL, val, -1); if (result == 0) { return sizeof(target_ulong); } @@ -405,6 +155,38 @@ static int riscv_gdb_set_virtual(CPURISCVState *cs, uint8_t *mem_buf, int n) return 0; } +static int riscv_gen_dynamic_csr_xml(CPUState *cs, int base_reg) +{ + RISCVCPU *cpu = RISCV_CPU(cs); + CPURISCVState *env = &cpu->env; + GString *s = g_string_new(NULL); + riscv_csr_predicate_fn predicate; + int bitsize = riscv_cpu_is_32bit(env) ? 32 : 64; + int i; + + g_string_printf(s, ""); + g_string_append_printf(s, ""); + g_string_append_printf(s, ""); + + for (i = 0; i < CSR_TABLE_SIZE; i++) { + predicate = csr_ops[i].predicate; + if (predicate && !predicate(env, i)) { + if (csr_ops[i].name) { + g_string_append_printf(s, "", base_reg + i); + } + } + + g_string_append_printf(s, ""); + + cpu->dyn_csr_xml = g_string_free(s, false); + return CSR_TABLE_SIZE; +} + void riscv_cpu_register_gdb_regs_for_features(CPUState *cs) { RISCVCPU *cpu = RISCV_CPU(cs); @@ -417,16 +199,14 @@ void riscv_cpu_register_gdb_regs_for_features(CPUState *cs) 36, "riscv-32bit-fpu.xml", 0); } #if defined(TARGET_RISCV32) - gdb_register_coprocessor(cs, riscv_gdb_get_csr, riscv_gdb_set_csr, - 240, "riscv-32bit-csr.xml", 0); - gdb_register_coprocessor(cs, riscv_gdb_get_virtual, riscv_gdb_set_virtual, 1, "riscv-32bit-virtual.xml", 0); #elif defined(TARGET_RISCV64) - gdb_register_coprocessor(cs, riscv_gdb_get_csr, riscv_gdb_set_csr, - 240, "riscv-64bit-csr.xml", 0); - gdb_register_coprocessor(cs, riscv_gdb_get_virtual, riscv_gdb_set_virtual, 1, "riscv-64bit-virtual.xml", 0); #endif + + gdb_register_coprocessor(cs, riscv_gdb_get_csr, riscv_gdb_set_csr, + riscv_gen_dynamic_csr_xml(cs, cs->gdb_num_regs), + "riscv-csr.xml", 0); }