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 
get_cpu(bool has_vcpu,int vcpu,Error ** errp)16 static CPUState *get_cpu(bool has_vcpu, int vcpu, Error **errp)
17 {
18     if (has_vcpu) {
19         CPUState *cpu = qemu_get_cpu(vcpu);
20         if (cpu == NULL) {
21             error_setg(errp, "invalid vCPU index %u", vcpu);
22         }
23         return cpu;
24     } else {
25         return NULL;
26     }
27 }
28 
check_events(bool has_vcpu,bool ignore_unavailable,bool is_pattern,const char * name,Error ** errp)29 static bool check_events(bool has_vcpu, bool ignore_unavailable, bool is_pattern,
30                          const char *name, Error **errp)
31 {
32     if (!is_pattern) {
33         TraceEvent *ev = trace_event_name(name);
34 
35         /* error for non-existing event */
36         if (ev == NULL) {
37             error_setg(errp, "unknown event \"%s\"", name);
38             return false;
39         }
40 
41         /* error for non-vcpu event */
42         if (has_vcpu && !trace_event_is_vcpu(ev)) {
43             error_setg(errp, "event \"%s\" is not vCPU-specific", name);
44             return false;
45         }
46 
47         /* error for unavailable event */
48         if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
49             error_setg(errp, "event \"%s\" is disabled", name);
50             return false;
51         }
52 
53         return true;
54     } else {
55         /* error for unavailable events */
56         TraceEventIter iter;
57         TraceEvent *ev;
58         trace_event_iter_init(&iter, name);
59         while ((ev = trace_event_iter_next(&iter)) != NULL) {
60             if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
61                 error_setg(errp, "event \"%s\" is disabled", trace_event_get_name(ev));
62                 return false;
63             }
64         }
65         return true;
66     }
67 }
68 
qmp_trace_event_get_state(const char * name,bool has_vcpu,int64_t vcpu,Error ** errp)69 TraceEventInfoList *qmp_trace_event_get_state(const char *name,
70                                               bool has_vcpu, int64_t vcpu,
71                                               Error **errp)
72 {
73     Error *err = NULL;
74     TraceEventInfoList *events = NULL;
75     TraceEventIter iter;
76     TraceEvent *ev;
77     bool is_pattern = trace_event_is_pattern(name);
78     CPUState *cpu;
79 
80     /* Check provided vcpu */
81     cpu = get_cpu(has_vcpu, vcpu, &err);
82     if (err) {
83         error_propagate(errp, err);
84         return NULL;
85     }
86 
87     /* Check events */
88     if (!check_events(has_vcpu, true, is_pattern, name, errp)) {
89         return NULL;
90     }
91 
92     /* Get states (all errors checked above) */
93     trace_event_iter_init(&iter, name);
94     while ((ev = trace_event_iter_next(&iter)) != NULL) {
95         TraceEventInfoList *elem;
96         bool is_vcpu = trace_event_is_vcpu(ev);
97         if (has_vcpu && !is_vcpu) {
98             continue;
99         }
100 
101         elem = g_new(TraceEventInfoList, 1);
102         elem->value = g_new(TraceEventInfo, 1);
103         elem->value->vcpu = is_vcpu;
104         elem->value->name = g_strdup(trace_event_get_name(ev));
105 
106         if (!trace_event_get_state_static(ev)) {
107             elem->value->state = TRACE_EVENT_STATE_UNAVAILABLE;
108         } else {
109             if (has_vcpu) {
110                 if (is_vcpu) {
111                     if (trace_event_get_vcpu_state_dynamic(cpu, ev)) {
112                         elem->value->state = TRACE_EVENT_STATE_ENABLED;
113                     } else {
114                         elem->value->state = TRACE_EVENT_STATE_DISABLED;
115                     }
116                 }
117                 /* else: already skipped above */
118             } else {
119                 if (trace_event_get_state_dynamic(ev)) {
120                     elem->value->state = TRACE_EVENT_STATE_ENABLED;
121                 } else {
122                     elem->value->state = TRACE_EVENT_STATE_DISABLED;
123                 }
124             }
125         }
126         elem->next = events;
127         events = elem;
128     }
129 
130     return events;
131 }
132 
qmp_trace_event_set_state(const char * name,bool enable,bool has_ignore_unavailable,bool ignore_unavailable,bool has_vcpu,int64_t vcpu,Error ** errp)133 void qmp_trace_event_set_state(const char *name, bool enable,
134                                bool has_ignore_unavailable, bool ignore_unavailable,
135                                bool has_vcpu, int64_t vcpu,
136                                Error **errp)
137 {
138     Error *err = NULL;
139     TraceEventIter iter;
140     TraceEvent *ev;
141     bool is_pattern = trace_event_is_pattern(name);
142     CPUState *cpu;
143 
144     /* Check provided vcpu */
145     cpu = get_cpu(has_vcpu, vcpu, &err);
146     if (err) {
147         error_propagate(errp, err);
148         return;
149     }
150 
151     /* Check events */
152     if (!check_events(has_vcpu, has_ignore_unavailable && ignore_unavailable,
153                       is_pattern, name, errp)) {
154         return;
155     }
156 
157     /* Apply changes (all errors checked above) */
158     trace_event_iter_init(&iter, name);
159     while ((ev = trace_event_iter_next(&iter)) != NULL) {
160         if (!trace_event_get_state_static(ev) ||
161             (has_vcpu && !trace_event_is_vcpu(ev))) {
162             continue;
163         }
164         if (has_vcpu) {
165             trace_event_set_vcpu_state_dynamic(cpu, ev, enable);
166         } else {
167             trace_event_set_state_dynamic(ev, enable);
168         }
169     }
170 }
171