[Qemu-devel] [PATCH v3 15/24] instrument: [qmp, qapi] Add control interface

[Lluís Vilanova]

Add QMP commands to control (un)loading of dynamic instrumentation library.

Signed-off-by: Lluís Vilanova <address@hidden>
---
 instrument/Makefile.objs    |    2 +
 instrument/control.h        |    4 +
 instrument/qapi-schema.json |  124 +++++++++++++++++++++++++++++++++++++++++++
 instrument/qmp.c            |   78 +++++++++++++++++++++++++++
 qmp-commands.hx             |   71 +++++++++++++++++++++++++
 qmp.c                       |    4 +
 6 files changed, 283 insertions(+)
 create mode 100644 instrument/qmp.c

diff --git a/instrument/Makefile.objs b/instrument/Makefile.objs
index e571c71..af1c96b 100644
--- a/instrument/Makefile.objs
+++ b/instrument/Makefile.objs
@@ -66,3 +66,5 @@ endif
 # Control code
 
 target-obj-y += control.o
+
+common-obj-$(CONFIG_SOFTMMU) += qmp.o
diff --git a/instrument/control.h b/instrument/control.h
index a6a648a..77d77ad 100644
--- a/instrument/control.h
+++ b/instrument/control.h
@@ -21,6 +21,8 @@
  * @INSTR_LOAD_ERROR: Error with libdl (see dlerror).
  *
  * Error codes for instr_load().
+ *
+ * Warning: Keep in sync with #InstrLoadCode
  */
 typedef enum {
     INSTR_LOAD_OK,
@@ -36,6 +38,8 @@ typedef enum {
  * @INSTR_UNLOAD_ERROR: Error with libdl (see dlerror).
  *
  * Error codes for instr_unload().
+ *
+ * Warning: Keep in sync with #InstrUnloadCode
  */
 typedef enum {
     INSTR_UNLOAD_OK,
diff --git a/instrument/qapi-schema.json b/instrument/qapi-schema.json
index e450ddf..900160b 100644
--- a/instrument/qapi-schema.json
+++ b/instrument/qapi-schema.json
@@ -24,3 +24,127 @@
 ##
 { 'enum': 'InstrType',
   'data': [ 'None', 'Static', 'Dynamic' ] }
+
+##
+# @InstrState
+#
+# Instrumentation state.
+#
+# Instrumentation is never active if @type is #None.
+#
+# Instrumentation is always active if @type is #Static.
+#
+# @type: The system's @InstrType.
+#
+# @active: Whether an instrumentation is loaded.
+#
+# @handles: List of handles for currently loaded instrumentation libraries.
+#
+# Since: 1.5
+##
+{ 'type': 'InstrState',
+  'data': { 'type': 'InstrType', 'active': 'bool' } }
+
+##
+# @instr-query:
+#
+# Returns the current instrumentation state.
+#
+# Since: 1.5
+##
+{ 'command': 'instr-query',
+  'returns': 'InstrState' }
+
+
+##
+# @InstrLoadCode
+#
+# Result code of an 'instr-load' command.
+#
+# @OK: Correctly loaded.
+#
+# @Unavailable: Service not available.
+#
+# @Error: Error with libdl (see 'msg').
+#
+# Since: 1.5
+##
+{ 'enum': 'InstrLoadCode'
+  'data': [ 'OK', 'Unavailable', 'Error' ] }
+
+##
+# @InstrLoadResult
+#
+# Result of an 'instr-load' command.
+#
+# @code: Result code.
+#
+# @msg: Additional error message.
+#
+# @handle: Instrumentation library identifier (undefined in case of error).
+#
+# Since: 1.5
+##
+{ 'type': 'InstrLoadResult'
+  'data': { 'code': 'InstrLoadCode', 'msg': 'str', 'handle': 'int' } }
+
+##
+# @instr-load:
+#
+# Load an instrumentation library.
+#
+# @path: path to the dynamic instrumentation library
+#
+# @args: arguments to the dynamic instrumentation library
+#
+# Since: 1.5
+##
+{ 'command': 'instr-load',
+  'data':    { 'path': 'str', '*args': ['String'] },
+  'returns': 'InstrLoadResult' }
+
+
+##
+# @InstrUnloadCode
+#
+# Result code of an 'instr-unload' command.
+#
+# @OK: Correctly unloaded.
+#
+# @Unavailable: Service not available.
+#
+# @Invalid: Invalid handle.
+#
+# @Error: Error with libdl (see 'msg').
+#
+# Since: 1.5
+##
+{ 'enum': 'InstrUnloadCode'
+  'data': [ 'OK', 'Unavailable', 'Invalid', 'Error' ] }
+
+##
+# @InstrUnloadResult
+#
+# Result of an 'instr-unload' command.
+#
+# @code: Result code.
+#
+# @msg: Additional error message.
+#
+# Since: 1.5
+##
+{ 'type': 'InstrUnloadResult'
+  'data': { 'code': 'InstrUnloadCode', 'msg': 'str' } }
+
+##
+# @instr-unload:
+#
+# Unload an instrumentation library.
+#
+# @handle: Instrumentation library identifier (see #InstrLoadResult).
+#
+# Since: 1.5
+##
+{ 'command': 'instr-unload',
+  'data': { 'handle': 'int' },
+  'returns': 'InstrUnloadResult' }
diff --git a/instrument/qmp.c b/instrument/qmp.c
new file mode 100644
index 0000000..780c06e
--- /dev/null
+++ b/instrument/qmp.c
@@ -0,0 +1,78 @@
+/*
+ * QMP interface for dynamic trace instrumentation control commands.
+ *
+ * Copyright (C) 2012-2013 Lluís Vilanova <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu-common.h"
+#include "qapi/qmp/qerror.h"
+#include "qmp-commands.h"
+
+#include <dlfcn.h>
+
+#include "instrument/control.h"
+
+
+
+InstrState *qmp_instr_query (Error **errp)
+{
+    InstrState *res = g_malloc0(sizeof(*res));
+    res->type = instr_type();
+    res->active = instr_active();
+    return res;
+}
+
+InstrLoadResult *qmp_instr_load(const char * path,
+                                bool have_args, StringList * args,
+                                Error **errp)
+{
+    int argc = 0;
+    const char **argv = NULL;
+
+    StringList *entry = have_args ? args : NULL;
+    while (entry != NULL) {
+        argv = realloc(argv, sizeof(*argv) * (argc + 1));
+        argv[argc] = entry->value->str;
+        argc++;
+        entry = entry->next;
+    }
+
+    InstrLoadResult *res = g_malloc0(sizeof(*res));
+    res->code = instr_load(path, argc, argv, &res->handle);
+    switch (res->code) {
+    case INSTR_LOAD_CODE_OK:
+    case INSTR_LOAD_CODE_UNAVAILABLE:
+        break;
+    case INSTR_LOAD_CODE_ERROR:
+        res->msg = dlerror();
+        break;
+    default:
+        fprintf(stderr, "Unknown instrumentation load code: %d", res->code);
+        exit(1);
+        break;
+    }
+    return res;
+}
+
+InstrUnloadResult *qmp_instr_unload(int64_t handle, Error **errp)
+{
+    InstrUnloadResult *res = g_malloc0(sizeof(*res));
+    res->code = instr_unload(handle);
+    switch (res->code) {
+    case INSTR_UNLOAD_OK:
+    case INSTR_UNLOAD_UNAVAILABLE:
+    case INSTR_UNLOAD_INVALID:
+        break;
+    case INSTR_UNLOAD_CODE_ERROR:
+        res->msg = dlerror();
+        break;
+    default:
+        fprintf(stderr, "Unknown instrumentation unload code: %d", res->code);
+        exit(1);
+        break;
+    }
+    return res;
+}
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 1e0e11e..65873dd 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1510,6 +1510,77 @@ Notes:
     o Commands that prompt the user for data (eg. 'cont' when the block
       device is encrypted) don't currently work
 
+instr-query
+-----------
+
+Query the instrumentation state.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "instr-query" }
+<- { "return": { "type": "Dynamic", "active": "None" } }
+
+EQMP
+
+    {
+        .name       = "instr-query",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_instr_query,
+    },
+
+
+SQMP
+
+instr-load
+----------
+
+Load a dynamic instrumentation library.
+
+Arguments:
+
+- path: path to the dynamic instrumentation library
+- args: arguments to the dynamic instrumentation library
+
+Example:
+
+-> { "execute": "instr-load", "arguments": { "path": 
"/tmp/libtrace-instrument.so" } }
+<- { "return": {} }
+
+EQMP
+
+    {
+        .name       = "instr-load",
+        .args_type  = "path:F,args:s?",
+        .mhandler.cmd_new = qmp_marshal_input_instr_load,
+    },
+
+
+SQMP
+
+instr-unload
+------------
+
+Unload the current dynamic instrumentation library.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "instr-unload" }
+<- { "return": {} }
+
+EQMP
+
+    {
+        .name       = "instr-unload",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_instr_unload,
+    },
+
+
+SQMP
 3. Query Commands
 =================
 
diff --git a/qmp.c b/qmp.c
index 55b056b..72abe03 100644
--- a/qmp.c
+++ b/qmp.c
@@ -24,6 +24,10 @@
 #include "hw/qdev.h"
 #include "sysemu/blockdev.h"
 #include "qom/qom-qobject.h"
+#if defined(TRACE_INSTRUMENT_DYNAMIC)
+#include "instrument/qi-qmp-commands.h"
+#endif
+
 
 NameInfo *qmp_query_name(Error **errp)
 {