xref: /qemu/trace/qmp.c (revision 89aafcf2) 
1 /*
2  * QMP commands for tracing events.
3  *
4  * Copyright (C) 2014-2016 Lluís Vilanova <vilanova@ac.upc.edu>
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "qapi/error.h"
12 #include "qapi/qapi-commands-trace.h"
13 #include "control-vcpu.h"
14 
15 
16 static bool check_events(bool ignore_unavailable, bool is_pattern,
17                          const char *name, Error **errp)
18 {
19     if (!is_pattern) {
20         TraceEvent *ev = trace_event_name(name);
21 
22         /* error for non-existing event */
23         if (ev == NULL) {
24             error_setg(errp, "unknown event \"%s\"", name);
25             return false;
26         }
27 
28         /* error for unavailable event */
29         if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
30             error_setg(errp, "event \"%s\" is disabled", name);
31             return false;
32         }
33 
34         return true;
35     } else {
36         /* error for unavailable events */
37         TraceEventIter iter;
38         TraceEvent *ev;
39         trace_event_iter_init_pattern(&iter, name);
40         while ((ev = trace_event_iter_next(&iter)) != NULL) {
41             if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
42                 error_setg(errp, "event \"%s\" is disabled", trace_event_get_name(ev));
43                 return false;
44             }
45         }
46         return true;
47     }
48 }
49 
50 TraceEventInfoList *qmp_trace_event_get_state(const char *name,
51                                               bool has_vcpu, int64_t vcpu,
52                                               Error **errp)
53 {
54     TraceEventInfoList *events = NULL;
55     TraceEventIter iter;
56     TraceEvent *ev;
57     bool is_pattern = trace_event_is_pattern(name);
58 
59     /* Check events */
60     if (!check_events(true, is_pattern, name, errp)) {
61         return NULL;
62     }
63 
64     /* Get states (all errors checked above) */
65     trace_event_iter_init_pattern(&iter, name);
66     while ((ev = trace_event_iter_next(&iter)) != NULL) {
67         TraceEventInfo *value;
68 
69         value = g_new(TraceEventInfo, 1);
70         value->name = g_strdup(trace_event_get_name(ev));
71 
72         if (!trace_event_get_state_static(ev)) {
73             value->state = TRACE_EVENT_STATE_UNAVAILABLE;
74         } else {
75             if (trace_event_get_state_dynamic(ev)) {
76                 value->state = TRACE_EVENT_STATE_ENABLED;
77             } else {
78                 value->state = TRACE_EVENT_STATE_DISABLED;
79             }
80         }
81         QAPI_LIST_PREPEND(events, value);
82     }
83 
84     return events;
85 }
86 
87 void qmp_trace_event_set_state(const char *name, bool enable,
88                                bool has_ignore_unavailable, bool ignore_unavailable,
89                                bool has_vcpu, int64_t vcpu,
90                                Error **errp)
91 {
92     TraceEventIter iter;
93     TraceEvent *ev;
94     bool is_pattern = trace_event_is_pattern(name);
95 
96     /* Check events */
97     if (!check_events(has_ignore_unavailable && ignore_unavailable,
98                       is_pattern, name, errp)) {
99         return;
100     }
101 
102     /* Apply changes (all errors checked above) */
103     trace_event_iter_init_pattern(&iter, name);
104     while ((ev = trace_event_iter_next(&iter)) != NULL) {
105         if (!trace_event_get_state_static(ev)) {
106             continue;
107         }
108         trace_event_set_state_dynamic(ev, enable);
109     }
110 }
111