diff options
| -rw-r--r-- | docs/tracing.txt | 48 | ||||
| -rw-r--r-- | hmp-commands.hx | 7 | ||||
| -rw-r--r-- | monitor.c | 9 |
3 files changed, 40 insertions, 24 deletions
diff --git a/docs/tracing.txt b/docs/tracing.txt index 1ad106a5d7..41eb8e6fec 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -108,6 +108,36 @@ portability macros, ensure they are preceded and followed by double quotes: of trace events. Marking trace events disabled by default saves the user from having to manually disable noisy trace events. +== Generic interface and monitor commands == + +You can programmatically query and control the dynamic state of trace events +through a backend-agnostic interface: + +* trace_print_events + +* trace_event_set_state + Enables or disables trace events at runtime inside QEMU. + The function returns "true" if the state of the event has been successfully + changed, or "false" otherwise: + + #include "trace/control.h" + + trace_event_set_state("virtio_irq", true); /* enable */ + [...] + trace_event_set_state("virtio_irq", false); /* disable */ + +Note that some of the backends do not provide an implementation for this +interface, in which case QEMU will just print a warning. + +This functionality is also provided through monitor commands: + +* info trace-events + View available trace events and their state. State 1 means enabled, state 0 + means disabled. + +* trace-event NAME on|off + Enable/disable a given trace event. + == Trace backends == The "tracetool" script automates tedious trace event code generation and also @@ -157,27 +187,9 @@ unless you have specific needs for more advanced backends. flushed and emptied. This means the 'info trace' will display few or no entries if the buffer has just been flushed. -* info trace-events - View available trace events and their state. State 1 means enabled, state 0 - means disabled. - -* trace-event NAME on|off - Enable/disable a given trace event. - * trace-file on|off|flush|set <path> Enable/disable/flush the trace file or set the trace file name. -==== Enabling/disabling trace events programmatically ==== - -The st_change_trace_event_state() function can be used to enable or disable trace -events at runtime inside QEMU: - - #include "trace.h" - - st_change_trace_event_state("virtio_irq", true); /* enable */ - [...] - st_change_trace_event_state("virtio_irq", false); /* disable */ - ==== Analyzing trace files ==== The "simple" backend produces binary trace files that can be formatted with the diff --git a/hmp-commands.hx b/hmp-commands.hx index d77e75fa81..9e1cca8e3d 100644 --- a/hmp-commands.hx +++ b/hmp-commands.hx @@ -180,7 +180,6 @@ STEXI Output logs to @var{filename}. ETEXI -#ifdef CONFIG_TRACE_SIMPLE { .name = "trace-event", .args_type = "name:s,option:b", @@ -195,6 +194,7 @@ STEXI changes status of a trace event ETEXI +#if defined(CONFIG_SIMPLE_TRACE) { .name = "trace-file", .args_type = "op:s?,arg:F?", @@ -1358,10 +1358,13 @@ ETEXI STEXI @item info trace show contents of trace buffer +ETEXI +#endif + +STEXI @item info trace-events show available trace events and their state ETEXI -#endif STEXI @end table @@ -57,8 +57,9 @@ #include "json-parser.h" #include "osdep.h" #include "cpu.h" +#include "trace/control.h" #ifdef CONFIG_TRACE_SIMPLE -#include "trace.h" +#include "trace/simple.h" #endif #include "trace/control.h" #include "ui/qemu-spice.h" @@ -593,7 +594,6 @@ static void do_help_cmd(Monitor *mon, const QDict *qdict) help_cmd(mon, qdict_get_try_str(qdict, "name")); } -#ifdef CONFIG_TRACE_SIMPLE static void do_trace_event_set_state(Monitor *mon, const QDict *qdict) { const char *tp_name = qdict_get_str(qdict, "name"); @@ -605,6 +605,7 @@ static void do_trace_event_set_state(Monitor *mon, const QDict *qdict) } } +#ifdef CONFIG_SIMPLE_TRACE static void do_trace_file(Monitor *mon, const QDict *qdict) { const char *op = qdict_get_try_str(qdict, "op"); @@ -1002,12 +1003,12 @@ static void do_info_trace(Monitor *mon) { st_print_trace((FILE *)mon, &monitor_fprintf); } +#endif static void do_trace_print_events(Monitor *mon) { trace_print_events((FILE *)mon, &monitor_fprintf); } -#endif /** * do_quit(): Quit QEMU execution @@ -3144,6 +3145,7 @@ static const mon_cmd_t info_cmds[] = { .help = "show current contents of trace buffer", .mhandler.info = do_info_trace, }, +#endif { .name = "trace-events", .args_type = "", @@ -3151,7 +3153,6 @@ static const mon_cmd_t info_cmds[] = { .help = "show available trace-events & their state", .mhandler.info = do_trace_print_events, }, -#endif { .name = NULL, }, |