[PATCH v14 06/10] monitor: adding tb_stats hmp command

[Fei Wu]

From: "Vanderson M. do Rosario" <vandersonmr2@gmail.com>

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.

Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
Message-Id: <20190829173437.5926-8-vandersonmr2@gmail.com>
Message-Id: <20190829173437.5926-9-vandersonmr2@gmail.com>
[AJB: fix authorship]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Fei Wu <fei2.wu@intel.com>
---
 accel/tcg/monitor.c           |  45 +++++++++++++
 accel/tcg/tb-stats.c          | 121 +++++++++++++++++++++++++++++++++-
 hmp-commands.hx               |  16 +++++
 include/exec/tb-stats-flags.h |   2 +
 include/exec/tb-stats.h       |  10 +++
 include/monitor/hmp.h         |   1 +
 6 files changed, 192 insertions(+), 3 deletions(-)

diff --git a/accel/tcg/monitor.c b/accel/tcg/monitor.c
index 2bc87f2642..2e00f10267 100644
--- a/accel/tcg/monitor.c
+++ b/accel/tcg/monitor.c
@@ -11,7 +11,9 @@
 #include "qapi/error.h"
 #include "qapi/type-helpers.h"
 #include "qapi/qapi-commands-machine.h"
+#include "qapi/qmp/qdict.h"
 #include "monitor/monitor.h"
+#include "monitor/hmp.h"
 #include "sysemu/cpus.h"
 #include "sysemu/cpu-timers.h"
 #include "sysemu/tcg.h"
@@ -87,6 +89,49 @@ HumanReadableText *qmp_x_query_opcount(Error **errp)
 }
 
 #ifdef CONFIG_TCG
+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));
+
+}
+
 HumanReadableText *qmp_x_query_profile(Error **errp)
 {
     g_autoptr(GString) buf = g_string_new("");
diff --git a/accel/tcg/tb-stats.c b/accel/tcg/tb-stats.c
index 68ac7d3f73..805e1fc74d 100644
--- a/accel/tcg/tb-stats.c
+++ b/accel/tcg/tb-stats.c
@@ -16,18 +16,20 @@
 #include "qemu/timer.h"
 
 #include "exec/tb-stats.h"
+#include "exec/tb-flush.h"
 #include "tb-context.h"
 
 /* TBStatistic collection controls */
 enum TBStatsStatus {
     TB_STATS_DISABLED = 0,
     TB_STATS_RUNNING,
-    TB_STATS_PAUSED,
-    TB_STATS_STOPPED
+    TB_STATS_PAUSED
 };
 
 static enum TBStatsStatus tcg_collect_tb_stats;
 static uint32_t default_tbstats_flag;
+/* only accessed in safe work */
+static GList *last_search;
 
 uint64_t dev_time;
 
@@ -170,6 +172,101 @@ void dump_jit_profile_info(TCGProfile *s, GString *buf)
     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_enabled()) {
+            qemu_printf("TB information already being recorded");
+            return;
+        } else if (tb_stats_collection_paused()) {
+            set_tbstats_flags(level);
+        } else {
+            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_disabled()) {
+            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(void)
 {
     if (!tb_ctx.tb_stats.map && tb_stats_collection_enabled()) {
@@ -186,7 +283,7 @@ void enable_collect_tb_stats(void)
 
 void disable_collect_tb_stats(void)
 {
-    tcg_collect_tb_stats = TB_STATS_STOPPED;
+    tcg_collect_tb_stats = TB_STATS_DISABLED;
 }
 
 void pause_collect_tb_stats(void)
@@ -199,11 +296,29 @@ bool tb_stats_collection_enabled(void)
     return tcg_collect_tb_stats == TB_STATS_RUNNING;
 }
 
+bool tb_stats_collection_disabled(void)
+{
+    return tcg_collect_tb_stats == TB_STATS_DISABLED;
+}
+
 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_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 2cbd0f77a0..9a40215d34 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1670,6 +1670,22 @@ SRST
   Executes a qemu-io command on the given block device.
 ERST
 
+#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
+
+SRST
+``tb_stats`` *command* *stats_level*
+  Control recording tb statistics
+ERST
+
     {
         .name       = "qom-list",
         .args_type  = "path:s?",
diff --git a/include/exec/tb-stats-flags.h b/include/exec/tb-stats-flags.h
index 04adaee8d9..a3897c99b1 100644
--- a/include/exec/tb-stats-flags.h
+++ b/include/exec/tb-stats-flags.h
@@ -16,12 +16,14 @@
 #define TB_JIT_STATS  (1 << 2)
 #define TB_JIT_TIME   (1 << 3)
 #define TB_ALL_STATS  (TB_EXEC_STATS | TB_JIT_STATS | TB_JIT_TIME)
+#define TB_PAUSED     (1 << 4)
 
 /* TBStatistic collection controls */
 void enable_collect_tb_stats(void);
 void disable_collect_tb_stats(void);
 void pause_collect_tb_stats(void);
 bool tb_stats_collection_enabled(void);
+bool tb_stats_collection_disabled(void);
 bool tb_stats_collection_paused(void);
 
 uint32_t get_default_tbstats_flag(void);
diff --git a/include/exec/tb-stats.h b/include/exec/tb-stats.h
index 72585c448a..4bb343870b 100644
--- a/include/exec/tb-stats.h
+++ b/include/exec/tb-stats.h
@@ -33,6 +33,9 @@
 
 #include "exec/tb-stats-flags.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))
 
@@ -114,4 +117,11 @@ void init_tb_stats_htable(void);
 void dump_jit_profile_info(TCGProfile *s, GString *buf);
 void dump_jit_exec_time_info(uint64_t dev_time, GString *buf);
 
+struct TbstatsCommand {
+    enum TbstatsCmd cmd;
+    uint32_t level;
+};
+
+void do_hmp_tbstats_safe(CPUState *cpu, run_on_cpu_data icmd);
+
 #endif
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index 13f9a2dedb..2e7f141754 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -181,5 +181,6 @@ void hmp_ioport_write(Monitor *mon, const QDict *qdict);
 void hmp_boot_set(Monitor *mon, const QDict *qdict);
 void hmp_info_mtree(Monitor *mon, const QDict *qdict);
 void hmp_info_cryptodev(Monitor *mon, const QDict *qdict);
+void hmp_tbstats(Monitor *mon, const QDict *qdict);
 
 #endif
-- 
2.25.1