diff mbox series

[v1,1/4] target/riscv: Add itrigger support when icount is not enabled

Message ID 20221013062946.7530-2-zhiwei_liu@linux.alibaba.com
State New
Headers show
Series Support native debug icount trigger | expand

Commit Message

LIU Zhiwei Oct. 13, 2022, 6:29 a.m. UTC
When icount is not enabled, there is no API in QEMU that can get the
guest instruction number.

Translate the guest code in a way that each TB only has one instruction.
After executing the instruction, decrease the count by 1 until it reaches 0
where the itrigger fires.

Note that only when priviledge matches the itrigger configuration,
the count will decrease.

Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 target/riscv/cpu.h                            |  2 +
 target/riscv/cpu_helper.c                     |  6 ++
 target/riscv/debug.c                          | 71 +++++++++++++++++++
 target/riscv/debug.h                          | 12 ++++
 target/riscv/helper.h                         |  2 +
 .../riscv/insn_trans/trans_privileged.c.inc   |  4 +-
 target/riscv/insn_trans/trans_rvi.c.inc       |  8 +--
 target/riscv/insn_trans/trans_rvv.c.inc       |  4 +-
 target/riscv/translate.c                      | 33 ++++++++-
 9 files changed, 131 insertions(+), 11 deletions(-)

Comments

Alistair Francis Nov. 7, 2022, 1:37 a.m. UTC | #1
On Thu, Oct 13, 2022 at 4:32 PM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> When icount is not enabled, there is no API in QEMU that can get the
> guest instruction number.
>
> Translate the guest code in a way that each TB only has one instruction.

I don't think this is a great idea.

Why can't we just require icount be enabled if a user wants this? Or singlestep?

Alistair

> After executing the instruction, decrease the count by 1 until it reaches 0
> where the itrigger fires.
>
> Note that only when priviledge matches the itrigger configuration,
> the count will decrease.
>
> Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> ---
>  target/riscv/cpu.h                            |  2 +
>  target/riscv/cpu_helper.c                     |  6 ++
>  target/riscv/debug.c                          | 71 +++++++++++++++++++
>  target/riscv/debug.h                          | 12 ++++
>  target/riscv/helper.h                         |  2 +
>  .../riscv/insn_trans/trans_privileged.c.inc   |  4 +-
>  target/riscv/insn_trans/trans_rvi.c.inc       |  8 +--
>  target/riscv/insn_trans/trans_rvv.c.inc       |  4 +-
>  target/riscv/translate.c                      | 33 ++++++++-
>  9 files changed, 131 insertions(+), 11 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index b131fa8c8e..24bafda27d 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -621,6 +621,8 @@ FIELD(TB_FLAGS, PM_MASK_ENABLED, 22, 1)
>  FIELD(TB_FLAGS, PM_BASE_ENABLED, 23, 1)
>  FIELD(TB_FLAGS, VTA, 24, 1)
>  FIELD(TB_FLAGS, VMA, 25, 1)
> +/* Native debug itrigger */
> +FIELD(TB_FLAGS, ITRIGGER, 26, 1)
>
>  #ifdef TARGET_RISCV32
>  #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 278d163803..263282f230 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -27,7 +27,9 @@
>  #include "tcg/tcg-op.h"
>  #include "trace.h"
>  #include "semihosting/common-semi.h"
> +#include "sysemu/cpu-timers.h"
>  #include "cpu_bits.h"
> +#include "debug.h"
>
>  int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
>  {
> @@ -103,6 +105,10 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
>          flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
>                             get_field(env->mstatus_hs, MSTATUS_VS));
>      }
> +    if (riscv_feature(env, RISCV_FEATURE_DEBUG) && !icount_enabled()) {
> +        flags = FIELD_DP32(flags, TB_FLAGS, ITRIGGER,
> +                           riscv_itrigger_enabled(env));
> +    }
>  #endif
>
>      flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
> diff --git a/target/riscv/debug.c b/target/riscv/debug.c
> index 26ea764407..45a3537d5c 100644
> --- a/target/riscv/debug.c
> +++ b/target/riscv/debug.c
> @@ -29,6 +29,7 @@
>  #include "cpu.h"
>  #include "trace.h"
>  #include "exec/exec-all.h"
> +#include "exec/helper-proto.h"
>
>  /*
>   * The following M-mode trigger CSRs are implemented:
> @@ -498,6 +499,76 @@ static void type6_reg_write(CPURISCVState *env, target_ulong index,
>      return;
>  }
>
> +/* icount trigger type */
> +static inline int
> +itrigger_get_count(CPURISCVState *env, int index)
> +{
> +    return get_field(env->tdata1[index], ITRIGGER_COUNT);
> +}
> +
> +static inline void
> +itrigger_set_count(CPURISCVState *env, int index, int value)
> +{
> +    env->tdata1[index] = set_field(env->tdata1[index],
> +                                   ITRIGGER_COUNT, value);
> +}
> +
> +static bool check_itrigger_priv(CPURISCVState *env, int index)
> +{
> +    target_ulong tdata1 = env->tdata1[index];
> +    if (riscv_cpu_virt_enabled(env)) {
> +        /* check VU/VS bit against current privilege level */
> +        return (get_field(tdata1, ITRIGGER_VS) == env->priv) ||
> +               (get_field(tdata1, ITRIGGER_VU) == env->priv);
> +    } else {
> +        /* check U/S/M bit against current privilege level */
> +        return (get_field(tdata1, ITRIGGER_M) == env->priv) ||
> +               (get_field(tdata1, ITRIGGER_S) == env->priv) ||
> +               (get_field(tdata1, ITRIGGER_U) == env->priv);
> +    }
> +}
> +
> +bool riscv_itrigger_enabled(CPURISCVState *env)
> +{
> +    int count;
> +    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
> +        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
> +            continue;
> +        }
> +        if (check_itrigger_priv(env, i)) {
> +            continue;
> +        }
> +        count = itrigger_get_count(env, i);
> +        if (!count) {
> +            continue;
> +        }
> +        return true;
> +    }
> +
> +    return false;
> +}
> +
> +void helper_itrigger_match(CPURISCVState *env)
> +{
> +    int count;
> +    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
> +        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
> +            continue;
> +        }
> +        if (check_itrigger_priv(env, i)) {
> +            continue;
> +        }
> +        count = itrigger_get_count(env, i);
> +        if (!count) {
> +            continue;
> +        }
> +        itrigger_set_count(env, i, count--);
> +        if (!count) {
> +            do_trigger_action(env, i);
> +        }
> +    }
> +}
> +
>  target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
>  {
>      switch (tdata_index) {
> diff --git a/target/riscv/debug.h b/target/riscv/debug.h
> index a1226b4d29..cc3358e69b 100644
> --- a/target/riscv/debug.h
> +++ b/target/riscv/debug.h
> @@ -118,6 +118,17 @@ enum {
>      SIZE_NUM = 16
>  };
>
> +/* itrigger filed masks */
> +#define ITRIGGER_ACTION       0x3f
> +#define ITRIGGER_U            BIT(6)
> +#define ITRIGGER_S            BIT(7)
> +#define ITRIGGER_PENDING      BIT(8)
> +#define ITRIGGER_M            BIT(9)
> +#define ITRIGGER_COUNT        (0x3fff << 10)
> +#define ITRIGGER_HIT          BIT(24)
> +#define ITRIGGER_VU           BIT(25)
> +#define ITRIGGER_VS           BIT(26)
> +
>  bool tdata_available(CPURISCVState *env, int tdata_index);
>
>  target_ulong tselect_csr_read(CPURISCVState *env);
> @@ -134,4 +145,5 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
>
>  void riscv_trigger_init(CPURISCVState *env);
>
> +bool riscv_itrigger_enabled(CPURISCVState *env);
>  #endif /* RISCV_DEBUG_H */
> diff --git a/target/riscv/helper.h b/target/riscv/helper.h
> index a03014fe67..227c7122ef 100644
> --- a/target/riscv/helper.h
> +++ b/target/riscv/helper.h
> @@ -109,6 +109,8 @@ DEF_HELPER_1(sret, tl, env)
>  DEF_HELPER_1(mret, tl, env)
>  DEF_HELPER_1(wfi, void, env)
>  DEF_HELPER_1(tlb_flush, void, env)
> +/* Native Debug */
> +DEF_HELPER_1(itrigger_match, void, env)
>  #endif
>
>  /* Hypervisor functions */
> diff --git a/target/riscv/insn_trans/trans_privileged.c.inc b/target/riscv/insn_trans/trans_privileged.c.inc
> index 3281408a87..59501b2780 100644
> --- a/target/riscv/insn_trans/trans_privileged.c.inc
> +++ b/target/riscv/insn_trans/trans_privileged.c.inc
> @@ -78,7 +78,7 @@ static bool trans_sret(DisasContext *ctx, arg_sret *a)
>      if (has_ext(ctx, RVS)) {
>          decode_save_opc(ctx);
>          gen_helper_sret(cpu_pc, cpu_env);
> -        tcg_gen_exit_tb(NULL, 0); /* no chaining */
> +        exit_tb(ctx); /* no chaining */
>          ctx->base.is_jmp = DISAS_NORETURN;
>      } else {
>          return false;
> @@ -94,7 +94,7 @@ static bool trans_mret(DisasContext *ctx, arg_mret *a)
>  #ifndef CONFIG_USER_ONLY
>      decode_save_opc(ctx);
>      gen_helper_mret(cpu_pc, cpu_env);
> -    tcg_gen_exit_tb(NULL, 0); /* no chaining */
> +    exit_tb(ctx); /* no chaining */
>      ctx->base.is_jmp = DISAS_NORETURN;
>      return true;
>  #else
> diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
> index c49dbec0eb..5c69b88d1e 100644
> --- a/target/riscv/insn_trans/trans_rvi.c.inc
> +++ b/target/riscv/insn_trans/trans_rvi.c.inc
> @@ -66,7 +66,7 @@ static bool trans_jalr(DisasContext *ctx, arg_jalr *a)
>      }
>
>      gen_set_gpri(ctx, a->rd, ctx->pc_succ_insn);
> -    tcg_gen_lookup_and_goto_ptr();
> +    lookup_and_goto_ptr(ctx);
>
>      if (misaligned) {
>          gen_set_label(misaligned);
> @@ -803,7 +803,7 @@ static bool trans_pause(DisasContext *ctx, arg_pause *a)
>       * end the TB and return to main loop
>       */
>      gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> -    tcg_gen_exit_tb(NULL, 0);
> +    exit_tb(ctx);
>      ctx->base.is_jmp = DISAS_NORETURN;
>
>      return true;
> @@ -827,7 +827,7 @@ static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a)
>       * however we need to end the translation block
>       */
>      gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> -    tcg_gen_exit_tb(NULL, 0);
> +    exit_tb(ctx);
>      ctx->base.is_jmp = DISAS_NORETURN;
>      return true;
>  }
> @@ -838,7 +838,7 @@ static bool do_csr_post(DisasContext *ctx)
>      decode_save_opc(ctx);
>      /* We may have changed important cpu state -- exit to main loop. */
>      gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> -    tcg_gen_exit_tb(NULL, 0);
> +    exit_tb(ctx);
>      ctx->base.is_jmp = DISAS_NORETURN;
>      return true;
>  }
> diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
> index 4dea4413ae..d455acedbf 100644
> --- a/target/riscv/insn_trans/trans_rvv.c.inc
> +++ b/target/riscv/insn_trans/trans_rvv.c.inc
> @@ -196,7 +196,7 @@ static bool do_vsetvl(DisasContext *s, int rd, int rs1, TCGv s2)
>      mark_vs_dirty(s);
>
>      gen_set_pc_imm(s, s->pc_succ_insn);
> -    tcg_gen_lookup_and_goto_ptr();
> +    lookup_and_goto_ptr(s);
>      s->base.is_jmp = DISAS_NORETURN;
>
>      if (rd == 0 && rs1 == 0) {
> @@ -222,7 +222,7 @@ static bool do_vsetivli(DisasContext *s, int rd, TCGv s1, TCGv s2)
>      gen_set_gpr(s, rd, dst);
>      mark_vs_dirty(s);
>      gen_set_pc_imm(s, s->pc_succ_insn);
> -    tcg_gen_lookup_and_goto_ptr();
> +    lookup_and_goto_ptr(s);
>      s->base.is_jmp = DISAS_NORETURN;
>
>      return true;
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index db123da5ec..d704265a37 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -111,6 +111,8 @@ typedef struct DisasContext {
>      /* PointerMasking extension */
>      bool pm_mask_enabled;
>      bool pm_base_enabled;
> +    /* Use icount trigger for native debug */
> +    bool itrigger;
>      /* TCG of the current insn_start */
>      TCGOp *insn_start;
>  } DisasContext;
> @@ -252,15 +254,39 @@ static void gen_exception_inst_addr_mis(DisasContext *ctx)
>      generate_exception(ctx, RISCV_EXCP_INST_ADDR_MIS);
>  }
>
> +static void lookup_and_goto_ptr(DisasContext *ctx)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    if (ctx->itrigger) {
> +        gen_helper_itrigger_match(cpu_env);
> +    }
> +#endif
> +    tcg_gen_lookup_and_goto_ptr();
> +}
> +
> +static void exit_tb(DisasContext *ctx)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    if (ctx->itrigger) {
> +        gen_helper_itrigger_match(cpu_env);
> +    }
> +#endif
> +    tcg_gen_exit_tb(NULL, 0);
> +}
> +
>  static void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
>  {
> -    if (translator_use_goto_tb(&ctx->base, dest)) {
> +     /*
> +      * Under itrigger, instruction executes one by one like singlestep,
> +      * direct block chain benefits will be small.
> +      */
> +    if (translator_use_goto_tb(&ctx->base, dest) && !ctx->itrigger) {
>          tcg_gen_goto_tb(n);
>          gen_set_pc_imm(ctx, dest);
>          tcg_gen_exit_tb(ctx->base.tb, n);
>      } else {
>          gen_set_pc_imm(ctx, dest);
> -        tcg_gen_lookup_and_goto_ptr();
> +        lookup_and_goto_ptr(ctx);
>      }
>  }
>
> @@ -1136,6 +1162,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
>      memset(ctx->ftemp, 0, sizeof(ctx->ftemp));
>      ctx->pm_mask_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_MASK_ENABLED);
>      ctx->pm_base_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_BASE_ENABLED);
> +    ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
>      ctx->zero = tcg_constant_tl(0);
>  }
>
> @@ -1175,7 +1202,7 @@ static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
>
>      /* Only the first insn within a TB is allowed to cross a page boundary. */
>      if (ctx->base.is_jmp == DISAS_NEXT) {
> -        if (!is_same_page(&ctx->base, ctx->base.pc_next)) {
> +        if (ctx->itrigger || !is_same_page(&ctx->base, ctx->base.pc_next)) {
>              ctx->base.is_jmp = DISAS_TOO_MANY;
>          } else {
>              unsigned page_ofs = ctx->base.pc_next & ~TARGET_PAGE_MASK;
> --
> 2.17.1
>
>
LIU Zhiwei Nov. 7, 2022, 2:01 a.m. UTC | #2
On 2022/11/7 9:37, Alistair Francis wrote:
> On Thu, Oct 13, 2022 at 4:32 PM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>> When icount is not enabled, there is no API in QEMU that can get the
>> guest instruction number.
>>
>> Translate the guest code in a way that each TB only has one instruction.
> I don't think this is a great idea.
>
> Why can't we just require icount be enabled if a user wants this? Or singlestep?

This feature will only be used by users who want to  run the native gdb 
on Linux. If we run QEMU as a service,  after booting the kernel, we 
can't predicate whether the users will use native gdb.

Besides, icount can't be enabled on MTTCG currently (I am working on 
this problem) and I don't want to constraint the use of MTTCG even  when 
it is possible the users use native gdb (which may only occupy just a 
little time).


Thus, I give this fallback way to implement the itrigger.  The icount 
parameter can be used as an accelerated way.

Thanks,
Zhiwei

>
> Alistair
>
>> After executing the instruction, decrease the count by 1 until it reaches 0
>> where the itrigger fires.
>>
>> Note that only when priviledge matches the itrigger configuration,
>> the count will decrease.
>>
>> Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
>> ---
>>   target/riscv/cpu.h                            |  2 +
>>   target/riscv/cpu_helper.c                     |  6 ++
>>   target/riscv/debug.c                          | 71 +++++++++++++++++++
>>   target/riscv/debug.h                          | 12 ++++
>>   target/riscv/helper.h                         |  2 +
>>   .../riscv/insn_trans/trans_privileged.c.inc   |  4 +-
>>   target/riscv/insn_trans/trans_rvi.c.inc       |  8 +--
>>   target/riscv/insn_trans/trans_rvv.c.inc       |  4 +-
>>   target/riscv/translate.c                      | 33 ++++++++-
>>   9 files changed, 131 insertions(+), 11 deletions(-)
>>
>> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
>> index b131fa8c8e..24bafda27d 100644
>> --- a/target/riscv/cpu.h
>> +++ b/target/riscv/cpu.h
>> @@ -621,6 +621,8 @@ FIELD(TB_FLAGS, PM_MASK_ENABLED, 22, 1)
>>   FIELD(TB_FLAGS, PM_BASE_ENABLED, 23, 1)
>>   FIELD(TB_FLAGS, VTA, 24, 1)
>>   FIELD(TB_FLAGS, VMA, 25, 1)
>> +/* Native debug itrigger */
>> +FIELD(TB_FLAGS, ITRIGGER, 26, 1)
>>
>>   #ifdef TARGET_RISCV32
>>   #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
>> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
>> index 278d163803..263282f230 100644
>> --- a/target/riscv/cpu_helper.c
>> +++ b/target/riscv/cpu_helper.c
>> @@ -27,7 +27,9 @@
>>   #include "tcg/tcg-op.h"
>>   #include "trace.h"
>>   #include "semihosting/common-semi.h"
>> +#include "sysemu/cpu-timers.h"
>>   #include "cpu_bits.h"
>> +#include "debug.h"
>>
>>   int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
>>   {
>> @@ -103,6 +105,10 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
>>           flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
>>                              get_field(env->mstatus_hs, MSTATUS_VS));
>>       }
>> +    if (riscv_feature(env, RISCV_FEATURE_DEBUG) && !icount_enabled()) {
>> +        flags = FIELD_DP32(flags, TB_FLAGS, ITRIGGER,
>> +                           riscv_itrigger_enabled(env));
>> +    }
>>   #endif
>>
>>       flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
>> diff --git a/target/riscv/debug.c b/target/riscv/debug.c
>> index 26ea764407..45a3537d5c 100644
>> --- a/target/riscv/debug.c
>> +++ b/target/riscv/debug.c
>> @@ -29,6 +29,7 @@
>>   #include "cpu.h"
>>   #include "trace.h"
>>   #include "exec/exec-all.h"
>> +#include "exec/helper-proto.h"
>>
>>   /*
>>    * The following M-mode trigger CSRs are implemented:
>> @@ -498,6 +499,76 @@ static void type6_reg_write(CPURISCVState *env, target_ulong index,
>>       return;
>>   }
>>
>> +/* icount trigger type */
>> +static inline int
>> +itrigger_get_count(CPURISCVState *env, int index)
>> +{
>> +    return get_field(env->tdata1[index], ITRIGGER_COUNT);
>> +}
>> +
>> +static inline void
>> +itrigger_set_count(CPURISCVState *env, int index, int value)
>> +{
>> +    env->tdata1[index] = set_field(env->tdata1[index],
>> +                                   ITRIGGER_COUNT, value);
>> +}
>> +
>> +static bool check_itrigger_priv(CPURISCVState *env, int index)
>> +{
>> +    target_ulong tdata1 = env->tdata1[index];
>> +    if (riscv_cpu_virt_enabled(env)) {
>> +        /* check VU/VS bit against current privilege level */
>> +        return (get_field(tdata1, ITRIGGER_VS) == env->priv) ||
>> +               (get_field(tdata1, ITRIGGER_VU) == env->priv);
>> +    } else {
>> +        /* check U/S/M bit against current privilege level */
>> +        return (get_field(tdata1, ITRIGGER_M) == env->priv) ||
>> +               (get_field(tdata1, ITRIGGER_S) == env->priv) ||
>> +               (get_field(tdata1, ITRIGGER_U) == env->priv);
>> +    }
>> +}
>> +
>> +bool riscv_itrigger_enabled(CPURISCVState *env)
>> +{
>> +    int count;
>> +    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
>> +        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
>> +            continue;
>> +        }
>> +        if (check_itrigger_priv(env, i)) {
>> +            continue;
>> +        }
>> +        count = itrigger_get_count(env, i);
>> +        if (!count) {
>> +            continue;
>> +        }
>> +        return true;
>> +    }
>> +
>> +    return false;
>> +}
>> +
>> +void helper_itrigger_match(CPURISCVState *env)
>> +{
>> +    int count;
>> +    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
>> +        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
>> +            continue;
>> +        }
>> +        if (check_itrigger_priv(env, i)) {
>> +            continue;
>> +        }
>> +        count = itrigger_get_count(env, i);
>> +        if (!count) {
>> +            continue;
>> +        }
>> +        itrigger_set_count(env, i, count--);
>> +        if (!count) {
>> +            do_trigger_action(env, i);
>> +        }
>> +    }
>> +}
>> +
>>   target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
>>   {
>>       switch (tdata_index) {
>> diff --git a/target/riscv/debug.h b/target/riscv/debug.h
>> index a1226b4d29..cc3358e69b 100644
>> --- a/target/riscv/debug.h
>> +++ b/target/riscv/debug.h
>> @@ -118,6 +118,17 @@ enum {
>>       SIZE_NUM = 16
>>   };
>>
>> +/* itrigger filed masks */
>> +#define ITRIGGER_ACTION       0x3f
>> +#define ITRIGGER_U            BIT(6)
>> +#define ITRIGGER_S            BIT(7)
>> +#define ITRIGGER_PENDING      BIT(8)
>> +#define ITRIGGER_M            BIT(9)
>> +#define ITRIGGER_COUNT        (0x3fff << 10)
>> +#define ITRIGGER_HIT          BIT(24)
>> +#define ITRIGGER_VU           BIT(25)
>> +#define ITRIGGER_VS           BIT(26)
>> +
>>   bool tdata_available(CPURISCVState *env, int tdata_index);
>>
>>   target_ulong tselect_csr_read(CPURISCVState *env);
>> @@ -134,4 +145,5 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
>>
>>   void riscv_trigger_init(CPURISCVState *env);
>>
>> +bool riscv_itrigger_enabled(CPURISCVState *env);
>>   #endif /* RISCV_DEBUG_H */
>> diff --git a/target/riscv/helper.h b/target/riscv/helper.h
>> index a03014fe67..227c7122ef 100644
>> --- a/target/riscv/helper.h
>> +++ b/target/riscv/helper.h
>> @@ -109,6 +109,8 @@ DEF_HELPER_1(sret, tl, env)
>>   DEF_HELPER_1(mret, tl, env)
>>   DEF_HELPER_1(wfi, void, env)
>>   DEF_HELPER_1(tlb_flush, void, env)
>> +/* Native Debug */
>> +DEF_HELPER_1(itrigger_match, void, env)
>>   #endif
>>
>>   /* Hypervisor functions */
>> diff --git a/target/riscv/insn_trans/trans_privileged.c.inc b/target/riscv/insn_trans/trans_privileged.c.inc
>> index 3281408a87..59501b2780 100644
>> --- a/target/riscv/insn_trans/trans_privileged.c.inc
>> +++ b/target/riscv/insn_trans/trans_privileged.c.inc
>> @@ -78,7 +78,7 @@ static bool trans_sret(DisasContext *ctx, arg_sret *a)
>>       if (has_ext(ctx, RVS)) {
>>           decode_save_opc(ctx);
>>           gen_helper_sret(cpu_pc, cpu_env);
>> -        tcg_gen_exit_tb(NULL, 0); /* no chaining */
>> +        exit_tb(ctx); /* no chaining */
>>           ctx->base.is_jmp = DISAS_NORETURN;
>>       } else {
>>           return false;
>> @@ -94,7 +94,7 @@ static bool trans_mret(DisasContext *ctx, arg_mret *a)
>>   #ifndef CONFIG_USER_ONLY
>>       decode_save_opc(ctx);
>>       gen_helper_mret(cpu_pc, cpu_env);
>> -    tcg_gen_exit_tb(NULL, 0); /* no chaining */
>> +    exit_tb(ctx); /* no chaining */
>>       ctx->base.is_jmp = DISAS_NORETURN;
>>       return true;
>>   #else
>> diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
>> index c49dbec0eb..5c69b88d1e 100644
>> --- a/target/riscv/insn_trans/trans_rvi.c.inc
>> +++ b/target/riscv/insn_trans/trans_rvi.c.inc
>> @@ -66,7 +66,7 @@ static bool trans_jalr(DisasContext *ctx, arg_jalr *a)
>>       }
>>
>>       gen_set_gpri(ctx, a->rd, ctx->pc_succ_insn);
>> -    tcg_gen_lookup_and_goto_ptr();
>> +    lookup_and_goto_ptr(ctx);
>>
>>       if (misaligned) {
>>           gen_set_label(misaligned);
>> @@ -803,7 +803,7 @@ static bool trans_pause(DisasContext *ctx, arg_pause *a)
>>        * end the TB and return to main loop
>>        */
>>       gen_set_pc_imm(ctx, ctx->pc_succ_insn);
>> -    tcg_gen_exit_tb(NULL, 0);
>> +    exit_tb(ctx);
>>       ctx->base.is_jmp = DISAS_NORETURN;
>>
>>       return true;
>> @@ -827,7 +827,7 @@ static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a)
>>        * however we need to end the translation block
>>        */
>>       gen_set_pc_imm(ctx, ctx->pc_succ_insn);
>> -    tcg_gen_exit_tb(NULL, 0);
>> +    exit_tb(ctx);
>>       ctx->base.is_jmp = DISAS_NORETURN;
>>       return true;
>>   }
>> @@ -838,7 +838,7 @@ static bool do_csr_post(DisasContext *ctx)
>>       decode_save_opc(ctx);
>>       /* We may have changed important cpu state -- exit to main loop. */
>>       gen_set_pc_imm(ctx, ctx->pc_succ_insn);
>> -    tcg_gen_exit_tb(NULL, 0);
>> +    exit_tb(ctx);
>>       ctx->base.is_jmp = DISAS_NORETURN;
>>       return true;
>>   }
>> diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
>> index 4dea4413ae..d455acedbf 100644
>> --- a/target/riscv/insn_trans/trans_rvv.c.inc
>> +++ b/target/riscv/insn_trans/trans_rvv.c.inc
>> @@ -196,7 +196,7 @@ static bool do_vsetvl(DisasContext *s, int rd, int rs1, TCGv s2)
>>       mark_vs_dirty(s);
>>
>>       gen_set_pc_imm(s, s->pc_succ_insn);
>> -    tcg_gen_lookup_and_goto_ptr();
>> +    lookup_and_goto_ptr(s);
>>       s->base.is_jmp = DISAS_NORETURN;
>>
>>       if (rd == 0 && rs1 == 0) {
>> @@ -222,7 +222,7 @@ static bool do_vsetivli(DisasContext *s, int rd, TCGv s1, TCGv s2)
>>       gen_set_gpr(s, rd, dst);
>>       mark_vs_dirty(s);
>>       gen_set_pc_imm(s, s->pc_succ_insn);
>> -    tcg_gen_lookup_and_goto_ptr();
>> +    lookup_and_goto_ptr(s);
>>       s->base.is_jmp = DISAS_NORETURN;
>>
>>       return true;
>> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
>> index db123da5ec..d704265a37 100644
>> --- a/target/riscv/translate.c
>> +++ b/target/riscv/translate.c
>> @@ -111,6 +111,8 @@ typedef struct DisasContext {
>>       /* PointerMasking extension */
>>       bool pm_mask_enabled;
>>       bool pm_base_enabled;
>> +    /* Use icount trigger for native debug */
>> +    bool itrigger;
>>       /* TCG of the current insn_start */
>>       TCGOp *insn_start;
>>   } DisasContext;
>> @@ -252,15 +254,39 @@ static void gen_exception_inst_addr_mis(DisasContext *ctx)
>>       generate_exception(ctx, RISCV_EXCP_INST_ADDR_MIS);
>>   }
>>
>> +static void lookup_and_goto_ptr(DisasContext *ctx)
>> +{
>> +#ifndef CONFIG_USER_ONLY
>> +    if (ctx->itrigger) {
>> +        gen_helper_itrigger_match(cpu_env);
>> +    }
>> +#endif
>> +    tcg_gen_lookup_and_goto_ptr();
>> +}
>> +
>> +static void exit_tb(DisasContext *ctx)
>> +{
>> +#ifndef CONFIG_USER_ONLY
>> +    if (ctx->itrigger) {
>> +        gen_helper_itrigger_match(cpu_env);
>> +    }
>> +#endif
>> +    tcg_gen_exit_tb(NULL, 0);
>> +}
>> +
>>   static void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
>>   {
>> -    if (translator_use_goto_tb(&ctx->base, dest)) {
>> +     /*
>> +      * Under itrigger, instruction executes one by one like singlestep,
>> +      * direct block chain benefits will be small.
>> +      */
>> +    if (translator_use_goto_tb(&ctx->base, dest) && !ctx->itrigger) {
>>           tcg_gen_goto_tb(n);
>>           gen_set_pc_imm(ctx, dest);
>>           tcg_gen_exit_tb(ctx->base.tb, n);
>>       } else {
>>           gen_set_pc_imm(ctx, dest);
>> -        tcg_gen_lookup_and_goto_ptr();
>> +        lookup_and_goto_ptr(ctx);
>>       }
>>   }
>>
>> @@ -1136,6 +1162,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
>>       memset(ctx->ftemp, 0, sizeof(ctx->ftemp));
>>       ctx->pm_mask_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_MASK_ENABLED);
>>       ctx->pm_base_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_BASE_ENABLED);
>> +    ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
>>       ctx->zero = tcg_constant_tl(0);
>>   }
>>
>> @@ -1175,7 +1202,7 @@ static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
>>
>>       /* Only the first insn within a TB is allowed to cross a page boundary. */
>>       if (ctx->base.is_jmp == DISAS_NEXT) {
>> -        if (!is_same_page(&ctx->base, ctx->base.pc_next)) {
>> +        if (ctx->itrigger || !is_same_page(&ctx->base, ctx->base.pc_next)) {
>>               ctx->base.is_jmp = DISAS_TOO_MANY;
>>           } else {
>>               unsigned page_ofs = ctx->base.pc_next & ~TARGET_PAGE_MASK;
>> --
>> 2.17.1
>>
>>
Alex Bennée Nov. 7, 2022, 3:58 p.m. UTC | #3
LIU Zhiwei <zhiwei_liu@linux.alibaba.com> writes:

> On 2022/11/7 9:37, Alistair Francis wrote:
>> On Thu, Oct 13, 2022 at 4:32 PM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>>> When icount is not enabled, there is no API in QEMU that can get the
>>> guest instruction number.
>>>
>>> Translate the guest code in a way that each TB only has one instruction.
>> I don't think this is a great idea.
>>
>> Why can't we just require icount be enabled if a user wants this? Or singlestep?
>
> This feature will only be used by users who want to  run the native
> gdb on Linux. If we run QEMU as a service,  after booting the kernel,
> we can't predicate whether the users will use native gdb.
>
> Besides, icount can't be enabled on MTTCG currently (I am working on
> this problem)

I'm curious as to what your approach is going to be to solve this one?
LIU Zhiwei Nov. 8, 2022, 1:54 a.m. UTC | #4
On 2022/11/7 23:58, Alex Bennée wrote:
> LIU Zhiwei<zhiwei_liu@linux.alibaba.com>  writes:
>
>> On 2022/11/7 9:37, Alistair Francis wrote:
>>> On Thu, Oct 13, 2022 at 4:32 PM LIU Zhiwei<zhiwei_liu@linux.alibaba.com>  wrote:
>>>> When icount is not enabled, there is no API in QEMU that can get the
>>>> guest instruction number.
>>>>
>>>> Translate the guest code in a way that each TB only has one instruction.
>>> I don't think this is a great idea.
>>>
>>> Why can't we just require icount be enabled if a user wants this? Or singlestep?
>> This feature will only be used by users who want to  run the native
>> gdb on Linux. If we run QEMU as a service,  after booting the kernel,
>> we can't predicate whether the users will use native gdb.
>>
>> Besides, icount can't be enabled on MTTCG currently (I am working on
>> this problem)
> I'm curious as to what your approach is going to be to solve this one?

Yes, I am interested in this problem.  But actually, I don't find a 
clear way.

For RR or MTTCG, timers using QEMU_CLOCK_VIRTUAL will set the total 
icount_budget.

  * For RR smp, every cpu has configured the total icount_budget.

  * For MTTCG smp, every cpu can't be configured the total
    icount_budget.  But we can split the icount_budget, such as divide
    by smp.cpus, to each core. If one core consumed its budget, it will
    wait for other cores.  Another way is to kick other cores and split
    the remaining icount_budget.

I am not sure if there are many other problems related.  It a difficult 
problem. Looking forward to your advice.

Thanks,
Zhiwei

>
Alistair Francis Nov. 9, 2022, 10:33 p.m. UTC | #5
On Mon, Nov 7, 2022 at 12:01 PM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
>
> On 2022/11/7 9:37, Alistair Francis wrote:
> > On Thu, Oct 13, 2022 at 4:32 PM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
> >> When icount is not enabled, there is no API in QEMU that can get the
> >> guest instruction number.
> >>
> >> Translate the guest code in a way that each TB only has one instruction.
> > I don't think this is a great idea.
> >
> > Why can't we just require icount be enabled if a user wants this? Or singlestep?
>
> This feature will only be used by users who want to  run the native gdb
> on Linux. If we run QEMU as a service,  after booting the kernel, we
> can't predicate whether the users will use native gdb.

I understand. It just seems like an invasive change. It does seem like
x86 does something similar though.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

>
> Besides, icount can't be enabled on MTTCG currently (I am working on
> this problem) and I don't want to constraint the use of MTTCG even  when
> it is possible the users use native gdb (which may only occupy just a
> little time).
>
>
> Thus, I give this fallback way to implement the itrigger.  The icount
> parameter can be used as an accelerated way.
>
> Thanks,
> Zhiwei
>
> >
> > Alistair
> >
> >> After executing the instruction, decrease the count by 1 until it reaches 0
> >> where the itrigger fires.
> >>
> >> Note that only when priviledge matches the itrigger configuration,
> >> the count will decrease.
> >>
> >> Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> >> ---
> >>   target/riscv/cpu.h                            |  2 +
> >>   target/riscv/cpu_helper.c                     |  6 ++
> >>   target/riscv/debug.c                          | 71 +++++++++++++++++++
> >>   target/riscv/debug.h                          | 12 ++++
> >>   target/riscv/helper.h                         |  2 +
> >>   .../riscv/insn_trans/trans_privileged.c.inc   |  4 +-
> >>   target/riscv/insn_trans/trans_rvi.c.inc       |  8 +--
> >>   target/riscv/insn_trans/trans_rvv.c.inc       |  4 +-
> >>   target/riscv/translate.c                      | 33 ++++++++-
> >>   9 files changed, 131 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> >> index b131fa8c8e..24bafda27d 100644
> >> --- a/target/riscv/cpu.h
> >> +++ b/target/riscv/cpu.h
> >> @@ -621,6 +621,8 @@ FIELD(TB_FLAGS, PM_MASK_ENABLED, 22, 1)
> >>   FIELD(TB_FLAGS, PM_BASE_ENABLED, 23, 1)
> >>   FIELD(TB_FLAGS, VTA, 24, 1)
> >>   FIELD(TB_FLAGS, VMA, 25, 1)
> >> +/* Native debug itrigger */
> >> +FIELD(TB_FLAGS, ITRIGGER, 26, 1)
> >>
> >>   #ifdef TARGET_RISCV32
> >>   #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
> >> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> >> index 278d163803..263282f230 100644
> >> --- a/target/riscv/cpu_helper.c
> >> +++ b/target/riscv/cpu_helper.c
> >> @@ -27,7 +27,9 @@
> >>   #include "tcg/tcg-op.h"
> >>   #include "trace.h"
> >>   #include "semihosting/common-semi.h"
> >> +#include "sysemu/cpu-timers.h"
> >>   #include "cpu_bits.h"
> >> +#include "debug.h"
> >>
> >>   int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
> >>   {
> >> @@ -103,6 +105,10 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
> >>           flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
> >>                              get_field(env->mstatus_hs, MSTATUS_VS));
> >>       }
> >> +    if (riscv_feature(env, RISCV_FEATURE_DEBUG) && !icount_enabled()) {
> >> +        flags = FIELD_DP32(flags, TB_FLAGS, ITRIGGER,
> >> +                           riscv_itrigger_enabled(env));
> >> +    }
> >>   #endif
> >>
> >>       flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
> >> diff --git a/target/riscv/debug.c b/target/riscv/debug.c
> >> index 26ea764407..45a3537d5c 100644
> >> --- a/target/riscv/debug.c
> >> +++ b/target/riscv/debug.c
> >> @@ -29,6 +29,7 @@
> >>   #include "cpu.h"
> >>   #include "trace.h"
> >>   #include "exec/exec-all.h"
> >> +#include "exec/helper-proto.h"
> >>
> >>   /*
> >>    * The following M-mode trigger CSRs are implemented:
> >> @@ -498,6 +499,76 @@ static void type6_reg_write(CPURISCVState *env, target_ulong index,
> >>       return;
> >>   }
> >>
> >> +/* icount trigger type */
> >> +static inline int
> >> +itrigger_get_count(CPURISCVState *env, int index)
> >> +{
> >> +    return get_field(env->tdata1[index], ITRIGGER_COUNT);
> >> +}
> >> +
> >> +static inline void
> >> +itrigger_set_count(CPURISCVState *env, int index, int value)
> >> +{
> >> +    env->tdata1[index] = set_field(env->tdata1[index],
> >> +                                   ITRIGGER_COUNT, value);
> >> +}
> >> +
> >> +static bool check_itrigger_priv(CPURISCVState *env, int index)
> >> +{
> >> +    target_ulong tdata1 = env->tdata1[index];
> >> +    if (riscv_cpu_virt_enabled(env)) {
> >> +        /* check VU/VS bit against current privilege level */
> >> +        return (get_field(tdata1, ITRIGGER_VS) == env->priv) ||
> >> +               (get_field(tdata1, ITRIGGER_VU) == env->priv);
> >> +    } else {
> >> +        /* check U/S/M bit against current privilege level */
> >> +        return (get_field(tdata1, ITRIGGER_M) == env->priv) ||
> >> +               (get_field(tdata1, ITRIGGER_S) == env->priv) ||
> >> +               (get_field(tdata1, ITRIGGER_U) == env->priv);
> >> +    }
> >> +}
> >> +
> >> +bool riscv_itrigger_enabled(CPURISCVState *env)
> >> +{
> >> +    int count;
> >> +    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
> >> +        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
> >> +            continue;
> >> +        }
> >> +        if (check_itrigger_priv(env, i)) {
> >> +            continue;
> >> +        }
> >> +        count = itrigger_get_count(env, i);
> >> +        if (!count) {
> >> +            continue;
> >> +        }
> >> +        return true;
> >> +    }
> >> +
> >> +    return false;
> >> +}
> >> +
> >> +void helper_itrigger_match(CPURISCVState *env)
> >> +{
> >> +    int count;
> >> +    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
> >> +        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
> >> +            continue;
> >> +        }
> >> +        if (check_itrigger_priv(env, i)) {
> >> +            continue;
> >> +        }
> >> +        count = itrigger_get_count(env, i);
> >> +        if (!count) {
> >> +            continue;
> >> +        }
> >> +        itrigger_set_count(env, i, count--);
> >> +        if (!count) {
> >> +            do_trigger_action(env, i);
> >> +        }
> >> +    }
> >> +}
> >> +
> >>   target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
> >>   {
> >>       switch (tdata_index) {
> >> diff --git a/target/riscv/debug.h b/target/riscv/debug.h
> >> index a1226b4d29..cc3358e69b 100644
> >> --- a/target/riscv/debug.h
> >> +++ b/target/riscv/debug.h
> >> @@ -118,6 +118,17 @@ enum {
> >>       SIZE_NUM = 16
> >>   };
> >>
> >> +/* itrigger filed masks */
> >> +#define ITRIGGER_ACTION       0x3f
> >> +#define ITRIGGER_U            BIT(6)
> >> +#define ITRIGGER_S            BIT(7)
> >> +#define ITRIGGER_PENDING      BIT(8)
> >> +#define ITRIGGER_M            BIT(9)
> >> +#define ITRIGGER_COUNT        (0x3fff << 10)
> >> +#define ITRIGGER_HIT          BIT(24)
> >> +#define ITRIGGER_VU           BIT(25)
> >> +#define ITRIGGER_VS           BIT(26)
> >> +
> >>   bool tdata_available(CPURISCVState *env, int tdata_index);
> >>
> >>   target_ulong tselect_csr_read(CPURISCVState *env);
> >> @@ -134,4 +145,5 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
> >>
> >>   void riscv_trigger_init(CPURISCVState *env);
> >>
> >> +bool riscv_itrigger_enabled(CPURISCVState *env);
> >>   #endif /* RISCV_DEBUG_H */
> >> diff --git a/target/riscv/helper.h b/target/riscv/helper.h
> >> index a03014fe67..227c7122ef 100644
> >> --- a/target/riscv/helper.h
> >> +++ b/target/riscv/helper.h
> >> @@ -109,6 +109,8 @@ DEF_HELPER_1(sret, tl, env)
> >>   DEF_HELPER_1(mret, tl, env)
> >>   DEF_HELPER_1(wfi, void, env)
> >>   DEF_HELPER_1(tlb_flush, void, env)
> >> +/* Native Debug */
> >> +DEF_HELPER_1(itrigger_match, void, env)
> >>   #endif
> >>
> >>   /* Hypervisor functions */
> >> diff --git a/target/riscv/insn_trans/trans_privileged.c.inc b/target/riscv/insn_trans/trans_privileged.c.inc
> >> index 3281408a87..59501b2780 100644
> >> --- a/target/riscv/insn_trans/trans_privileged.c.inc
> >> +++ b/target/riscv/insn_trans/trans_privileged.c.inc
> >> @@ -78,7 +78,7 @@ static bool trans_sret(DisasContext *ctx, arg_sret *a)
> >>       if (has_ext(ctx, RVS)) {
> >>           decode_save_opc(ctx);
> >>           gen_helper_sret(cpu_pc, cpu_env);
> >> -        tcg_gen_exit_tb(NULL, 0); /* no chaining */
> >> +        exit_tb(ctx); /* no chaining */
> >>           ctx->base.is_jmp = DISAS_NORETURN;
> >>       } else {
> >>           return false;
> >> @@ -94,7 +94,7 @@ static bool trans_mret(DisasContext *ctx, arg_mret *a)
> >>   #ifndef CONFIG_USER_ONLY
> >>       decode_save_opc(ctx);
> >>       gen_helper_mret(cpu_pc, cpu_env);
> >> -    tcg_gen_exit_tb(NULL, 0); /* no chaining */
> >> +    exit_tb(ctx); /* no chaining */
> >>       ctx->base.is_jmp = DISAS_NORETURN;
> >>       return true;
> >>   #else
> >> diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
> >> index c49dbec0eb..5c69b88d1e 100644
> >> --- a/target/riscv/insn_trans/trans_rvi.c.inc
> >> +++ b/target/riscv/insn_trans/trans_rvi.c.inc
> >> @@ -66,7 +66,7 @@ static bool trans_jalr(DisasContext *ctx, arg_jalr *a)
> >>       }
> >>
> >>       gen_set_gpri(ctx, a->rd, ctx->pc_succ_insn);
> >> -    tcg_gen_lookup_and_goto_ptr();
> >> +    lookup_and_goto_ptr(ctx);
> >>
> >>       if (misaligned) {
> >>           gen_set_label(misaligned);
> >> @@ -803,7 +803,7 @@ static bool trans_pause(DisasContext *ctx, arg_pause *a)
> >>        * end the TB and return to main loop
> >>        */
> >>       gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> >> -    tcg_gen_exit_tb(NULL, 0);
> >> +    exit_tb(ctx);
> >>       ctx->base.is_jmp = DISAS_NORETURN;
> >>
> >>       return true;
> >> @@ -827,7 +827,7 @@ static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a)
> >>        * however we need to end the translation block
> >>        */
> >>       gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> >> -    tcg_gen_exit_tb(NULL, 0);
> >> +    exit_tb(ctx);
> >>       ctx->base.is_jmp = DISAS_NORETURN;
> >>       return true;
> >>   }
> >> @@ -838,7 +838,7 @@ static bool do_csr_post(DisasContext *ctx)
> >>       decode_save_opc(ctx);
> >>       /* We may have changed important cpu state -- exit to main loop. */
> >>       gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> >> -    tcg_gen_exit_tb(NULL, 0);
> >> +    exit_tb(ctx);
> >>       ctx->base.is_jmp = DISAS_NORETURN;
> >>       return true;
> >>   }
> >> diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
> >> index 4dea4413ae..d455acedbf 100644
> >> --- a/target/riscv/insn_trans/trans_rvv.c.inc
> >> +++ b/target/riscv/insn_trans/trans_rvv.c.inc
> >> @@ -196,7 +196,7 @@ static bool do_vsetvl(DisasContext *s, int rd, int rs1, TCGv s2)
> >>       mark_vs_dirty(s);
> >>
> >>       gen_set_pc_imm(s, s->pc_succ_insn);
> >> -    tcg_gen_lookup_and_goto_ptr();
> >> +    lookup_and_goto_ptr(s);
> >>       s->base.is_jmp = DISAS_NORETURN;
> >>
> >>       if (rd == 0 && rs1 == 0) {
> >> @@ -222,7 +222,7 @@ static bool do_vsetivli(DisasContext *s, int rd, TCGv s1, TCGv s2)
> >>       gen_set_gpr(s, rd, dst);
> >>       mark_vs_dirty(s);
> >>       gen_set_pc_imm(s, s->pc_succ_insn);
> >> -    tcg_gen_lookup_and_goto_ptr();
> >> +    lookup_and_goto_ptr(s);
> >>       s->base.is_jmp = DISAS_NORETURN;
> >>
> >>       return true;
> >> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> >> index db123da5ec..d704265a37 100644
> >> --- a/target/riscv/translate.c
> >> +++ b/target/riscv/translate.c
> >> @@ -111,6 +111,8 @@ typedef struct DisasContext {
> >>       /* PointerMasking extension */
> >>       bool pm_mask_enabled;
> >>       bool pm_base_enabled;
> >> +    /* Use icount trigger for native debug */
> >> +    bool itrigger;
> >>       /* TCG of the current insn_start */
> >>       TCGOp *insn_start;
> >>   } DisasContext;
> >> @@ -252,15 +254,39 @@ static void gen_exception_inst_addr_mis(DisasContext *ctx)
> >>       generate_exception(ctx, RISCV_EXCP_INST_ADDR_MIS);
> >>   }
> >>
> >> +static void lookup_and_goto_ptr(DisasContext *ctx)
> >> +{
> >> +#ifndef CONFIG_USER_ONLY
> >> +    if (ctx->itrigger) {
> >> +        gen_helper_itrigger_match(cpu_env);
> >> +    }
> >> +#endif
> >> +    tcg_gen_lookup_and_goto_ptr();
> >> +}
> >> +
> >> +static void exit_tb(DisasContext *ctx)
> >> +{
> >> +#ifndef CONFIG_USER_ONLY
> >> +    if (ctx->itrigger) {
> >> +        gen_helper_itrigger_match(cpu_env);
> >> +    }
> >> +#endif
> >> +    tcg_gen_exit_tb(NULL, 0);
> >> +}
> >> +
> >>   static void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
> >>   {
> >> -    if (translator_use_goto_tb(&ctx->base, dest)) {
> >> +     /*
> >> +      * Under itrigger, instruction executes one by one like singlestep,
> >> +      * direct block chain benefits will be small.
> >> +      */
> >> +    if (translator_use_goto_tb(&ctx->base, dest) && !ctx->itrigger) {
> >>           tcg_gen_goto_tb(n);
> >>           gen_set_pc_imm(ctx, dest);
> >>           tcg_gen_exit_tb(ctx->base.tb, n);
> >>       } else {
> >>           gen_set_pc_imm(ctx, dest);
> >> -        tcg_gen_lookup_and_goto_ptr();
> >> +        lookup_and_goto_ptr(ctx);
> >>       }
> >>   }
> >>
> >> @@ -1136,6 +1162,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
> >>       memset(ctx->ftemp, 0, sizeof(ctx->ftemp));
> >>       ctx->pm_mask_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_MASK_ENABLED);
> >>       ctx->pm_base_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_BASE_ENABLED);
> >> +    ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
> >>       ctx->zero = tcg_constant_tl(0);
> >>   }
> >>
> >> @@ -1175,7 +1202,7 @@ static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
> >>
> >>       /* Only the first insn within a TB is allowed to cross a page boundary. */
> >>       if (ctx->base.is_jmp == DISAS_NEXT) {
> >> -        if (!is_same_page(&ctx->base, ctx->base.pc_next)) {
> >> +        if (ctx->itrigger || !is_same_page(&ctx->base, ctx->base.pc_next)) {
> >>               ctx->base.is_jmp = DISAS_TOO_MANY;
> >>           } else {
> >>               unsigned page_ofs = ctx->base.pc_next & ~TARGET_PAGE_MASK;
> >> --
> >> 2.17.1
> >>
> >>
diff mbox series

Patch

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index b131fa8c8e..24bafda27d 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -621,6 +621,8 @@  FIELD(TB_FLAGS, PM_MASK_ENABLED, 22, 1)
 FIELD(TB_FLAGS, PM_BASE_ENABLED, 23, 1)
 FIELD(TB_FLAGS, VTA, 24, 1)
 FIELD(TB_FLAGS, VMA, 25, 1)
+/* Native debug itrigger */
+FIELD(TB_FLAGS, ITRIGGER, 26, 1)
 
 #ifdef TARGET_RISCV32
 #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 278d163803..263282f230 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -27,7 +27,9 @@ 
 #include "tcg/tcg-op.h"
 #include "trace.h"
 #include "semihosting/common-semi.h"
+#include "sysemu/cpu-timers.h"
 #include "cpu_bits.h"
+#include "debug.h"
 
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
 {
@@ -103,6 +105,10 @@  void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
         flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
                            get_field(env->mstatus_hs, MSTATUS_VS));
     }
+    if (riscv_feature(env, RISCV_FEATURE_DEBUG) && !icount_enabled()) {
+        flags = FIELD_DP32(flags, TB_FLAGS, ITRIGGER,
+                           riscv_itrigger_enabled(env));
+    }
 #endif
 
     flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
diff --git a/target/riscv/debug.c b/target/riscv/debug.c
index 26ea764407..45a3537d5c 100644
--- a/target/riscv/debug.c
+++ b/target/riscv/debug.c
@@ -29,6 +29,7 @@ 
 #include "cpu.h"
 #include "trace.h"
 #include "exec/exec-all.h"
+#include "exec/helper-proto.h"
 
 /*
  * The following M-mode trigger CSRs are implemented:
@@ -498,6 +499,76 @@  static void type6_reg_write(CPURISCVState *env, target_ulong index,
     return;
 }
 
+/* icount trigger type */
+static inline int
+itrigger_get_count(CPURISCVState *env, int index)
+{
+    return get_field(env->tdata1[index], ITRIGGER_COUNT);
+}
+
+static inline void
+itrigger_set_count(CPURISCVState *env, int index, int value)
+{
+    env->tdata1[index] = set_field(env->tdata1[index],
+                                   ITRIGGER_COUNT, value);
+}
+
+static bool check_itrigger_priv(CPURISCVState *env, int index)
+{
+    target_ulong tdata1 = env->tdata1[index];
+    if (riscv_cpu_virt_enabled(env)) {
+        /* check VU/VS bit against current privilege level */
+        return (get_field(tdata1, ITRIGGER_VS) == env->priv) ||
+               (get_field(tdata1, ITRIGGER_VU) == env->priv);
+    } else {
+        /* check U/S/M bit against current privilege level */
+        return (get_field(tdata1, ITRIGGER_M) == env->priv) ||
+               (get_field(tdata1, ITRIGGER_S) == env->priv) ||
+               (get_field(tdata1, ITRIGGER_U) == env->priv);
+    }
+}
+
+bool riscv_itrigger_enabled(CPURISCVState *env)
+{
+    int count;
+    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
+        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
+            continue;
+        }
+        if (check_itrigger_priv(env, i)) {
+            continue;
+        }
+        count = itrigger_get_count(env, i);
+        if (!count) {
+            continue;
+        }
+        return true;
+    }
+
+    return false;
+}
+
+void helper_itrigger_match(CPURISCVState *env)
+{
+    int count;
+    for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
+        if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
+            continue;
+        }
+        if (check_itrigger_priv(env, i)) {
+            continue;
+        }
+        count = itrigger_get_count(env, i);
+        if (!count) {
+            continue;
+        }
+        itrigger_set_count(env, i, count--);
+        if (!count) {
+            do_trigger_action(env, i);
+        }
+    }
+}
+
 target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
 {
     switch (tdata_index) {
diff --git a/target/riscv/debug.h b/target/riscv/debug.h
index a1226b4d29..cc3358e69b 100644
--- a/target/riscv/debug.h
+++ b/target/riscv/debug.h
@@ -118,6 +118,17 @@  enum {
     SIZE_NUM = 16
 };
 
+/* itrigger filed masks */
+#define ITRIGGER_ACTION       0x3f
+#define ITRIGGER_U            BIT(6)
+#define ITRIGGER_S            BIT(7)
+#define ITRIGGER_PENDING      BIT(8)
+#define ITRIGGER_M            BIT(9)
+#define ITRIGGER_COUNT        (0x3fff << 10)
+#define ITRIGGER_HIT          BIT(24)
+#define ITRIGGER_VU           BIT(25)
+#define ITRIGGER_VS           BIT(26)
+
 bool tdata_available(CPURISCVState *env, int tdata_index);
 
 target_ulong tselect_csr_read(CPURISCVState *env);
@@ -134,4 +145,5 @@  bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
 
 void riscv_trigger_init(CPURISCVState *env);
 
+bool riscv_itrigger_enabled(CPURISCVState *env);
 #endif /* RISCV_DEBUG_H */
diff --git a/target/riscv/helper.h b/target/riscv/helper.h
index a03014fe67..227c7122ef 100644
--- a/target/riscv/helper.h
+++ b/target/riscv/helper.h
@@ -109,6 +109,8 @@  DEF_HELPER_1(sret, tl, env)
 DEF_HELPER_1(mret, tl, env)
 DEF_HELPER_1(wfi, void, env)
 DEF_HELPER_1(tlb_flush, void, env)
+/* Native Debug */
+DEF_HELPER_1(itrigger_match, void, env)
 #endif
 
 /* Hypervisor functions */
diff --git a/target/riscv/insn_trans/trans_privileged.c.inc b/target/riscv/insn_trans/trans_privileged.c.inc
index 3281408a87..59501b2780 100644
--- a/target/riscv/insn_trans/trans_privileged.c.inc
+++ b/target/riscv/insn_trans/trans_privileged.c.inc
@@ -78,7 +78,7 @@  static bool trans_sret(DisasContext *ctx, arg_sret *a)
     if (has_ext(ctx, RVS)) {
         decode_save_opc(ctx);
         gen_helper_sret(cpu_pc, cpu_env);
-        tcg_gen_exit_tb(NULL, 0); /* no chaining */
+        exit_tb(ctx); /* no chaining */
         ctx->base.is_jmp = DISAS_NORETURN;
     } else {
         return false;
@@ -94,7 +94,7 @@  static bool trans_mret(DisasContext *ctx, arg_mret *a)
 #ifndef CONFIG_USER_ONLY
     decode_save_opc(ctx);
     gen_helper_mret(cpu_pc, cpu_env);
-    tcg_gen_exit_tb(NULL, 0); /* no chaining */
+    exit_tb(ctx); /* no chaining */
     ctx->base.is_jmp = DISAS_NORETURN;
     return true;
 #else
diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
index c49dbec0eb..5c69b88d1e 100644
--- a/target/riscv/insn_trans/trans_rvi.c.inc
+++ b/target/riscv/insn_trans/trans_rvi.c.inc
@@ -66,7 +66,7 @@  static bool trans_jalr(DisasContext *ctx, arg_jalr *a)
     }
 
     gen_set_gpri(ctx, a->rd, ctx->pc_succ_insn);
-    tcg_gen_lookup_and_goto_ptr();
+    lookup_and_goto_ptr(ctx);
 
     if (misaligned) {
         gen_set_label(misaligned);
@@ -803,7 +803,7 @@  static bool trans_pause(DisasContext *ctx, arg_pause *a)
      * end the TB and return to main loop
      */
     gen_set_pc_imm(ctx, ctx->pc_succ_insn);
-    tcg_gen_exit_tb(NULL, 0);
+    exit_tb(ctx);
     ctx->base.is_jmp = DISAS_NORETURN;
 
     return true;
@@ -827,7 +827,7 @@  static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a)
      * however we need to end the translation block
      */
     gen_set_pc_imm(ctx, ctx->pc_succ_insn);
-    tcg_gen_exit_tb(NULL, 0);
+    exit_tb(ctx);
     ctx->base.is_jmp = DISAS_NORETURN;
     return true;
 }
@@ -838,7 +838,7 @@  static bool do_csr_post(DisasContext *ctx)
     decode_save_opc(ctx);
     /* We may have changed important cpu state -- exit to main loop. */
     gen_set_pc_imm(ctx, ctx->pc_succ_insn);
-    tcg_gen_exit_tb(NULL, 0);
+    exit_tb(ctx);
     ctx->base.is_jmp = DISAS_NORETURN;
     return true;
 }
diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index 4dea4413ae..d455acedbf 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -196,7 +196,7 @@  static bool do_vsetvl(DisasContext *s, int rd, int rs1, TCGv s2)
     mark_vs_dirty(s);
 
     gen_set_pc_imm(s, s->pc_succ_insn);
-    tcg_gen_lookup_and_goto_ptr();
+    lookup_and_goto_ptr(s);
     s->base.is_jmp = DISAS_NORETURN;
 
     if (rd == 0 && rs1 == 0) {
@@ -222,7 +222,7 @@  static bool do_vsetivli(DisasContext *s, int rd, TCGv s1, TCGv s2)
     gen_set_gpr(s, rd, dst);
     mark_vs_dirty(s);
     gen_set_pc_imm(s, s->pc_succ_insn);
-    tcg_gen_lookup_and_goto_ptr();
+    lookup_and_goto_ptr(s);
     s->base.is_jmp = DISAS_NORETURN;
 
     return true;
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index db123da5ec..d704265a37 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -111,6 +111,8 @@  typedef struct DisasContext {
     /* PointerMasking extension */
     bool pm_mask_enabled;
     bool pm_base_enabled;
+    /* Use icount trigger for native debug */
+    bool itrigger;
     /* TCG of the current insn_start */
     TCGOp *insn_start;
 } DisasContext;
@@ -252,15 +254,39 @@  static void gen_exception_inst_addr_mis(DisasContext *ctx)
     generate_exception(ctx, RISCV_EXCP_INST_ADDR_MIS);
 }
 
+static void lookup_and_goto_ptr(DisasContext *ctx)
+{
+#ifndef CONFIG_USER_ONLY
+    if (ctx->itrigger) {
+        gen_helper_itrigger_match(cpu_env);
+    }
+#endif
+    tcg_gen_lookup_and_goto_ptr();
+}
+
+static void exit_tb(DisasContext *ctx)
+{
+#ifndef CONFIG_USER_ONLY
+    if (ctx->itrigger) {
+        gen_helper_itrigger_match(cpu_env);
+    }
+#endif
+    tcg_gen_exit_tb(NULL, 0);
+}
+
 static void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
 {
-    if (translator_use_goto_tb(&ctx->base, dest)) {
+     /*
+      * Under itrigger, instruction executes one by one like singlestep,
+      * direct block chain benefits will be small.
+      */
+    if (translator_use_goto_tb(&ctx->base, dest) && !ctx->itrigger) {
         tcg_gen_goto_tb(n);
         gen_set_pc_imm(ctx, dest);
         tcg_gen_exit_tb(ctx->base.tb, n);
     } else {
         gen_set_pc_imm(ctx, dest);
-        tcg_gen_lookup_and_goto_ptr();
+        lookup_and_goto_ptr(ctx);
     }
 }
 
@@ -1136,6 +1162,7 @@  static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     memset(ctx->ftemp, 0, sizeof(ctx->ftemp));
     ctx->pm_mask_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_MASK_ENABLED);
     ctx->pm_base_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_BASE_ENABLED);
+    ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
     ctx->zero = tcg_constant_tl(0);
 }
 
@@ -1175,7 +1202,7 @@  static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
 
     /* Only the first insn within a TB is allowed to cross a page boundary. */
     if (ctx->base.is_jmp == DISAS_NEXT) {
-        if (!is_same_page(&ctx->base, ctx->base.pc_next)) {
+        if (ctx->itrigger || !is_same_page(&ctx->base, ctx->base.pc_next)) {
             ctx->base.is_jmp = DISAS_TOO_MANY;
         } else {
             unsigned page_ofs = ctx->base.pc_next & ~TARGET_PAGE_MASK;