xref: /openbmc/qemu/trace/control-target.c (revision 93977402)
1 /*
2  * Interface for configuring and controlling the state of 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 "cpu.h"
12 #include "trace.h"
13 #include "trace/control.h"
14 #include "translate-all.h"
15 
16 
17 void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
18 {
19     bool state_pre;
20     assert(trace_event_get_state_static(ev));
21     /*
22      * We ignore the "vcpu" property here, since no vCPUs have been created
23      * yet. Then dstate can only be 1 or 0.
24      */
25     state_pre = *ev->dstate;
26     if (state_pre != state) {
27         if (state) {
28             trace_events_enabled_count++;
29             *ev->dstate = 1;
30         } else {
31             trace_events_enabled_count--;
32             *ev->dstate = 0;
33         }
34     }
35 }
36 
37 void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
38 {
39     CPUState *vcpu;
40     assert(trace_event_get_state_static(ev));
41     if (trace_event_is_vcpu(ev)) {
42         CPU_FOREACH(vcpu) {
43             trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
44         }
45     } else {
46         /* Without the "vcpu" property, dstate can only be 1 or 0 */
47         bool state_pre = *ev->dstate;
48         if (state_pre != state) {
49             if (state) {
50                 trace_events_enabled_count++;
51                 *ev->dstate = 1;
52             } else {
53                 trace_events_enabled_count--;
54                 *ev->dstate = 0;
55             }
56         }
57     }
58 }
59 
60 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
61                                         TraceEvent *ev, bool state)
62 {
63     TraceEventVCPUID vcpu_id;
64     bool state_pre;
65     assert(trace_event_get_state_static(ev));
66     assert(trace_event_is_vcpu(ev));
67     vcpu_id = trace_event_get_vcpu_id(ev);
68     state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
69     if (state_pre != state) {
70         if (state) {
71             trace_events_enabled_count++;
72             set_bit(vcpu_id, vcpu->trace_dstate);
73             (*ev->dstate)++;
74         } else {
75             trace_events_enabled_count--;
76             clear_bit(vcpu_id, vcpu->trace_dstate);
77             (*ev->dstate)--;
78         }
79     }
80 }
81 
82 static bool adding_first_cpu(void)
83 {
84     CPUState *cpu;
85     size_t count = 0;
86     CPU_FOREACH(cpu) {
87         count++;
88         if (count > 1) {
89             return false;
90         }
91     }
92     return true;
93 }
94 
95 void trace_init_vcpu(CPUState *vcpu)
96 {
97     TraceEventIter iter;
98     TraceEvent *ev;
99     trace_event_iter_init(&iter, NULL);
100     while ((ev = trace_event_iter_next(&iter)) != NULL) {
101         if (trace_event_is_vcpu(ev) &&
102             trace_event_get_state_static(ev) &&
103             trace_event_get_state_dynamic(ev)) {
104             if (adding_first_cpu()) {
105                 /* check preconditions */
106                 assert(*ev->dstate == 1);
107                 /* disable early-init state ... */
108                 *ev->dstate = 0;
109                 trace_events_enabled_count--;
110                 /* ... and properly re-enable */
111                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
112             } else {
113                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
114             }
115         }
116     }
117     trace_guest_cpu_enter(vcpu);
118 }
119