qapi: introduce x-query-opcount QMP command

This is a counterpart to the HMP "info opcount" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

accel/tcg/cpu-exec.c

@@ -1066,4 +1066,18 @@ HumanReadableText *qmp_x_query_jit(Error **errp)
     return human_readable_text_from_str(buf);
 }
 
+HumanReadableText *qmp_x_query_opcount(Error **errp)
+{
+    g_autoptr(GString) buf = g_string_new("");
+
+    if (!tcg_enabled()) {
+        error_setg(errp, "Opcode count information is only available with accel=tcg");
+        return NULL;
+    }
+
+    dump_opcount_info(buf);
+
+    return human_readable_text_from_str(buf);
+}
+
 #endif /* !CONFIG_USER_ONLY */

accel/tcg/hmp.c

@@ -6,15 +6,10 @@
 #include "monitor/monitor.h"
 #include "sysemu/tcg.h"
 
-static void hmp_info_opcount(Monitor *mon, const QDict *qdict)
-{
-    dump_opcount_info();
-}
-
 static void hmp_tcg_register(void)
 {
     monitor_register_hmp_info_hrt("jit", qmp_x_query_jit);
-    monitor_register_hmp("opcount", true, hmp_info_opcount);
+    monitor_register_hmp_info_hrt("opcount", qmp_x_query_opcount);
 }
 
 type_init(hmp_tcg_register);

accel/tcg/translate-all.c

@@ -2118,9 +2118,9 @@ void dump_exec_info(GString *buf)
     tcg_dump_info(buf);
 }
 
-void dump_opcount_info(void)
+void dump_opcount_info(GString *buf)
 {
-    tcg_dump_op_count();
+    tcg_dump_op_count(buf);
 }
 
 #else /* CONFIG_USER_ONLY */

include/exec/cpu-all.h

@@ -432,7 +432,7 @@ static inline bool tlb_hit(target_ulong tlb_addr, target_ulong addr)
 void dump_drift_info(GString *buf);
 /* accel/tcg/translate-all.c */
 void dump_exec_info(GString *buf);
-void dump_opcount_info(void);
+void dump_opcount_info(GString *buf);
 #endif /* CONFIG_TCG */
 
 #endif /* !CONFIG_USER_ONLY */

include/tcg/tcg.h

@@ -938,7 +938,7 @@ int tcg_check_temp_count(void);
 
 int64_t tcg_cpu_exec_time(void);
 void tcg_dump_info(GString *buf);
-void tcg_dump_op_count(void);
+void tcg_dump_op_count(GString *buf);
 
 #define TCG_CT_CONST  1 /* any constant of register size */
 

qapi/machine.json

@@ -1449,6 +1449,19 @@
 { 'command': 'x-query-numa',
   'returns': 'HumanReadableText' }
 
+##
+# @x-query-opcount:
+#
+# Query TCG opcode counters
+#
+# Returns: TCG opcode counters
+#
+# Since: 6.2
+##
+{ 'command': 'x-query-opcount',
+  'returns': 'HumanReadableText',
+  'if': 'CONFIG_TCG' }
+
 ##
 # @x-query-profile:
 #

tcg/tcg.c

@@ -4116,15 +4116,15 @@ static void tcg_profile_snapshot_table(TCGProfile *prof)
     tcg_profile_snapshot(prof, false, true);
 }
 
-void tcg_dump_op_count(void)
+void tcg_dump_op_count(GString *buf)
 {
     TCGProfile prof = {};
     int i;
 
     tcg_profile_snapshot_table(&prof);
     for (i = 0; i < NB_OPS; i++) {
-        qemu_printf("%s %" PRId64 "\n", tcg_op_defs[i].name,
-                    prof.table_op_count[i]);
+        g_string_append_printf(buf, "%s %" PRId64 "\n", tcg_op_defs[i].name,
+                               prof.table_op_count[i]);
     }
 }
 
@@ -4143,9 +4143,9 @@ int64_t tcg_cpu_exec_time(void)
     return ret;
 }
 #else
-void tcg_dump_op_count(void)
+void tcg_dump_op_count(GString *buf)
 {
-    qemu_printf("[TCG profiler not compiled]\n");
+    g_string_append_printf(buf, "[TCG profiler not compiled]\n");
 }
 
 int64_t tcg_cpu_exec_time(void)

tests/qtest/qmp-cmd-test.c

@@ -53,6 +53,7 @@ static int query_error_class(const char *cmd)
         { "x-query-usb", ERROR_CLASS_GENERIC_ERROR },
         /* Only valid with accel=tcg */
         { "x-query-jit", ERROR_CLASS_GENERIC_ERROR },
+        { "x-query-opcount", ERROR_CLASS_GENERIC_ERROR },
         { NULL, -1 }
     };
     int i;