[v5,07/10] monitor: adding tb_stats hmp command

Adding tb_stats [start|pause|stop|filter] command to hmp.
This allows controlling the collection of statistics.
It is also possible to set the level of collection:
all, jit, or exec.

tb_stats filter allow to only collect statistics for the TB
in the last_search list.

The goal of this command is to allow the dynamic exploration
of the TCG behavior and quality. Therefore, for now, a
corresponding QMP command is not worthwhile.

Signed-off-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
---
 accel/tcg/tb-stats.c    | 111 ++++++++++++++++++++++++++++++++++++++++
 hmp-commands.hx         |  17 ++++++
 include/exec/tb-stats.h |  12 +++++
 include/qemu-common.h   |   1 +
 monitor/misc.c          |  49 ++++++++++++++++++
 vl.c                    |   6 +++
 6 files changed, 196 insertions(+)

* vandersonmr (vandersonmr2@gmail.com) wrote:
> Adding tb_stats [start|pause|stop|filter] command to hmp.
> This allows controlling the collection of statistics.
> It is also possible to set the level of collection:
> all, jit, or exec.
> 
> tb_stats filter allow to only collect statistics for the TB
> in the last_search list.
> 
> The goal of this command is to allow the dynamic exploration
> of the TCG behavior and quality. Therefore, for now, a
> corresponding QMP command is not worthwhile.
> 
> Signed-off-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>

For HMP:

Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  accel/tcg/tb-stats.c    | 111 ++++++++++++++++++++++++++++++++++++++++
>  hmp-commands.hx         |  17 ++++++
>  include/exec/tb-stats.h |  12 +++++
>  include/qemu-common.h   |   1 +
>  monitor/misc.c          |  49 ++++++++++++++++++
>  vl.c                    |   6 +++
>  6 files changed, 196 insertions(+)
> 
> diff --git a/accel/tcg/tb-stats.c b/accel/tcg/tb-stats.c
> index dddb9d4537..f28fd7b434 100644
> --- a/accel/tcg/tb-stats.c
> +++ b/accel/tcg/tb-stats.c
> @@ -9,6 +9,9 @@
>  
>  #include "exec/tb-stats.h"
>  
> +/* only accessed in safe work */
> +static GList *last_search;
> +
>  uint64_t dev_time;
>  
>  struct jit_profile_info {
> @@ -140,6 +143,96 @@ void dump_jit_profile_info(TCGProfile *s)
>      g_free(jpi);
>  }
>  
> +static void free_tbstats(void *p, uint32_t hash, void *userp)
> +{
> +    g_free(p);
> +}
> +
> +static void clean_tbstats(void)
> +{
> +    /* remove all tb_stats */
> +    qht_iter(&tb_ctx.tb_stats, free_tbstats, NULL);
> +    qht_destroy(&tb_ctx.tb_stats);
> +}
> +
> +void do_hmp_tbstats_safe(CPUState *cpu, run_on_cpu_data icmd)
> +{
> +    struct TbstatsCommand *cmdinfo = icmd.host_ptr;
> +    int cmd = cmdinfo->cmd;
> +    uint32_t level = cmdinfo->level;
> +
> +    switch (cmd) {
> +    case START:
> +        if (tb_stats_collection_paused()) {
> +            set_tbstats_flags(level);
> +        } else {
> +            if (tb_stats_collection_enabled()) {
> +                qemu_printf("TB information already being recorded");
> +                return;
> +            }
> +            qht_init(&tb_ctx.tb_stats, tb_stats_cmp, CODE_GEN_HTABLE_SIZE,
> +                        QHT_MODE_AUTO_RESIZE);
> +        }
> +
> +        set_default_tbstats_flag(level);
> +        enable_collect_tb_stats();
> +        tb_flush(cpu);
> +        break;
> +    case PAUSE:
> +        if (!tb_stats_collection_enabled()) {
> +            qemu_printf("TB information not being recorded");
> +            return;
> +        }
> +
> +        /* Continue to create TBStatistic structures but stop collecting statistics */
> +        pause_collect_tb_stats();
> +        set_default_tbstats_flag(TB_NOTHING);
> +        set_tbstats_flags(TB_PAUSED);
> +        tb_flush(cpu);
> +        break;
> +    case STOP:
> +        if (!tb_stats_collection_enabled()) {
> +            qemu_printf("TB information not being recorded");
> +            return;
> +        }
> +
> +        /* Dissalloc all TBStatistics structures and stop creating new ones */
> +        disable_collect_tb_stats();
> +        clean_tbstats();
> +        tb_flush(cpu);
> +        break;
> +    case FILTER:
> +        if (!tb_stats_collection_enabled()) {
> +            qemu_printf("TB information not being recorded");
> +            return;
> +        }
> +        if (!last_search) {
> +            qemu_printf("no search on record! execute info tbs before filtering!");
> +            return;
> +        }
> +
> +        set_default_tbstats_flag(TB_NOTHING);
> +
> +        /* Set all tbstats as paused, then return only the ones from last_search */
> +        pause_collect_tb_stats();
> +        set_tbstats_flags(TB_PAUSED);
> +
> +        for (GList *iter = last_search; iter; iter = g_list_next(iter)) {
> +            TBStatistics *tbs = iter->data;
> +            tbs->stats_enabled = level;
> +        }
> +
> +        tb_flush(cpu);
> +
> +        break;
> +    default: /* INVALID */
> +        g_assert_not_reached();
> +        break;
> +    }
> +
> +    g_free(cmdinfo);
> +}
> +
>  
>  void init_tb_stats_htable_if_not(void)
>  {
> @@ -175,6 +268,24 @@ bool tb_stats_collection_paused(void)
>      return tcg_collect_tb_stats == TB_STATS_PAUSED;
>  }
>  
> +static void reset_tbstats_flag(void *p, uint32_t hash, void *userp)
> +{
> +    uint32_t flag = *((int *)userp);
> +    TBStatistics *tbs = p;
> +    tbs->stats_enabled = flag;
> +}
> +
> +void set_default_tbstats_flag(uint32_t flag)
> +{
> +    default_tbstats_flag = flag;
> +}
> +
> +void set_tbstats_flags(uint32_t flag)
> +{
> +    /* iterate over tbstats setting their flag as TB_NOTHING */
> +    qht_iter(&tb_ctx.tb_stats, reset_tbstats_flag, &flag);
> +}
> +
>  uint32_t get_default_tbstats_flag(void)
>  {
>      return default_tbstats_flag;
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index bfa5681dd2..419898751e 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1885,6 +1885,23 @@ STEXI
>  @findex qemu-io
>  Executes a qemu-io command on the given block device.
>  
> +ETEXI
> +#if defined(CONFIG_TCG)
> +    {
> +        .name       = "tb_stats",
> +        .args_type  = "command:s,level:s?",
> +        .params     = "command [stats_level]",
> +        .help       = "Control tb statistics collection:"
> +                        "tb_stats (start|pause|stop|filter) [all|jit_stats|exec_stats]",
> +        .cmd        = hmp_tbstats,
> +    },
> +#endif
> +
> +STEXI
> +@item tb_stats
> +@findex
> +Control recording tb statistics
> +
>  ETEXI
>  
>      {
> diff --git a/include/exec/tb-stats.h b/include/exec/tb-stats.h
> index c0948e606a..9271b90924 100644
> --- a/include/exec/tb-stats.h
> +++ b/include/exec/tb-stats.h
> @@ -6,6 +6,9 @@
>  #include "exec/tb-context.h"
>  #include "tcg.h"
>  
> +enum SortBy { SORT_BY_HOTNESS, SORT_BY_HG /* Host/Guest */, SORT_BY_SPILLS };
> +enum TbstatsCmd { START, PAUSE, STOP, FILTER };
> +
>  #define tb_stats_enabled(tb, JIT_STATS) \
>      (tb && tb->tb_stats && (tb->tb_stats->stats_enabled & JIT_STATS))
>  
> @@ -74,10 +77,18 @@ bool tb_stats_cmp(const void *ap, const void *bp);
>  
>  void dump_jit_exec_time_info(uint64_t dev_time);
>  
> +void set_tbstats_flags(uint32_t flags);
>  void init_tb_stats_htable_if_not(void);
>  
>  void dump_jit_profile_info(TCGProfile *s);
>  
> +struct TbstatsCommand {
> +    enum TbstatsCmd cmd;
> +    uint32_t level;
> +};
> +
> +void do_hmp_tbstats_safe(CPUState *cpu, run_on_cpu_data icmd);
> +
>  /* TBStatistic collection controls */
>  void enable_collect_tb_stats(void);
>  void disable_collect_tb_stats(void);
> @@ -85,6 +96,7 @@ void pause_collect_tb_stats(void);
>  bool tb_stats_collection_enabled(void);
>  bool tb_stats_collection_paused(void);
>  
> +void set_default_tbstats_flag(uint32_t flag);
>  uint32_t get_default_tbstats_flag(void);
>  
>  #endif
> diff --git a/include/qemu-common.h b/include/qemu-common.h
> index 362e48c445..ab736a1b05 100644
> --- a/include/qemu-common.h
> +++ b/include/qemu-common.h
> @@ -141,6 +141,7 @@ enum TBStatsStatus {
>  #define TB_EXEC_STATS 1
>  #define TB_JIT_STATS  2
>  #define TB_JIT_TIME   4
> +#define TB_PAUSED     8
>  
>  extern int tcg_collect_tb_stats;
>  extern uint32_t default_tbstats_flag;
> diff --git a/monitor/misc.c b/monitor/misc.c
> index 4839d6875f..6902e8addb 100644
> --- a/monitor/misc.c
> +++ b/monitor/misc.c
> @@ -74,6 +74,8 @@
>  #include "sysemu/cpus.h"
>  #include "qemu/cutils.h"
>  #include "tcg/tcg.h"
> +#include "exec/tb-stats.h"
> +#include "qemu-common.h"
>  
>  #if defined(TARGET_S390X)
>  #include "hw/s390x/storage-keys.h"
> @@ -459,6 +461,49 @@ static void hmp_info_registers(Monitor *mon, const QDict *qdict)
>  }
>  
>  #ifdef CONFIG_TCG
> +static void hmp_tbstats(Monitor *mon, const QDict *qdict)
> +{
> +    if (!tcg_enabled()) {
> +        error_report("TB information is only available with accel=tcg");
> +        return;
> +    }
> +
> +    char *cmd = (char *) qdict_get_try_str(qdict, "command");
> +    enum TbstatsCmd icmd = -1;
> +
> +    if (strcmp(cmd, "start") == 0) {
> +        icmd = START;
> +    } else if (strcmp(cmd, "pause") == 0) {
> +        icmd = PAUSE;
> +    } else if (strcmp(cmd, "stop") == 0) {
> +        icmd = STOP;
> +    } else if (strcmp(cmd, "filter") == 0) {
> +        icmd = FILTER;
> +    } else {
> +        error_report("invalid command!");
> +        return;
> +    }
> +
> +    char *slevel = (char *) qdict_get_try_str(qdict, "level");
> +    uint32_t level = TB_EXEC_STATS | TB_JIT_STATS | TB_JIT_TIME;
> +    if (slevel) {
> +        if (strcmp(slevel, "jit") == 0) {
> +            level = TB_JIT_STATS;
> +        } else if (strcmp(slevel, "exec") == 0) {
> +            level = TB_EXEC_STATS;
> +        } else if (strcmp(slevel, "time") == 0) {
> +            level = TB_JIT_TIME;
> +        }
> +    }
> +
> +    struct TbstatsCommand *tbscommand = g_new0(struct TbstatsCommand, 1);
> +    tbscommand->cmd = icmd;
> +    tbscommand->level = level;
> +    async_safe_run_on_cpu(first_cpu, do_hmp_tbstats_safe,
> +                          RUN_ON_CPU_HOST_PTR(tbscommand));
> +
> +}
> +
>  static void hmp_info_jit(Monitor *mon, const QDict *qdict)
>  {
>      if (!tcg_enabled()) {
> @@ -1089,8 +1134,12 @@ static void hmp_info_mtree(Monitor *mon, const QDict *qdict)
>  
>  static void hmp_info_profile(Monitor *mon, const QDict *qdict)
>  {
> +#ifdef CONFIG_TCG
>      dump_jit_exec_time_info(dev_time);
>      dev_time = 0;
> +#else
> +    error_report("TCG should be enabled!");
> +#endif
>  }
>  
>  /* Capture support */
> diff --git a/vl.c b/vl.c
> index ef7737a7bc..326090c36a 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1781,11 +1781,17 @@ static bool main_loop_should_exit(void)
>  
>  static void main_loop(void)
>  {
> +#ifdef CONFIG_TCG
>      uint64_t ti;
> +#endif
>      while (!main_loop_should_exit()) {
> +#ifdef CONFIG_TCG
>          ti = profile_getclock();
> +#endif
>          main_loop_wait(false);
> +#ifdef CONFIG_TCG
>          dev_time += profile_getclock() - ti;
> +#endif
>      }
>  }
>  
> -- 
> 2.22.0
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK