From: Lluís Date: Wed, 31 Aug 2011 18:31:31 +0000 (+0200) Subject: trace: add "-trace events" argument to control initial state X-Git-Tag: v1.0-rc0~365^2~5 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=23d15e860b33819ad76092fbb32577542fe0c44d;p=thirdparty%2Fqemu.git trace: add "-trace events" argument to control initial state The "-trace events" argument can be used to provide a file with a list of trace event names that will be enabled prior to starting execution, thus providing early tracing. This saves the user from manually toggling event states through the monitor interface or whichever backend-specific interface. Signed-off-by: Lluís Vilanova --- diff --git a/Makefile.objs b/Makefile.objs index 57a80e61305..036a4eb6abe 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -384,6 +384,8 @@ trace-nested-$(CONFIG_TRACE_DEFAULT) += default.o trace-nested-$(CONFIG_TRACE_SIMPLE) += simple.o trace-obj-$(CONFIG_TRACE_SIMPLE) += qemu-timer-common.o +trace-nested-y += control.o + trace-obj-y += $(addprefix trace/, $(trace-nested-y)) ###################################################################### diff --git a/docs/tracing.txt b/docs/tracing.txt index 41eb8e6fec1..455da37969e 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -138,6 +138,10 @@ This functionality is also provided through monitor commands: * trace-event NAME on|off Enable/disable a given trace event. +The "-trace events=" command line argument can be used to enable the +events listed in from the very beginning of the program. This file must +contain one event name per line. + == Trace backends == The "tracetool" script automates tedious trace event code generation and also diff --git a/qemu-config.c b/qemu-config.c index 4f3465d3843..7a7854fd06f 100644 --- a/qemu-config.c +++ b/qemu-config.c @@ -309,6 +309,9 @@ static QemuOptsList qemu_trace_opts = { .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head), .desc = { { + .name = "events", + .type = QEMU_OPT_STRING, + },{ .name = "file", .type = QEMU_OPT_STRING, }, diff --git a/qemu-options.hx b/qemu-options.hx index 2d29933ab17..edd181bb8e9 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2437,17 +2437,29 @@ Normally QEMU loads a configuration file from @var{sysconfdir}/qemu.conf and option will prevent QEMU from loading these configuration files at startup. ETEXI DEF("trace", HAS_ARG, QEMU_OPTION_trace, - "-trace\n" - " Specify a trace file to log traces to\n", + "-trace [events=][,file=]\n" + " specify tracing options\n", QEMU_ARCH_ALL) STEXI -HXCOMM This line is not accurate, as the option is backend-specific but HX does -HXCOMM not support conditional compilation of text. -@item -trace +HXCOMM This line is not accurate, as some sub-options are backend-specific but +HXCOMM HX does not support conditional compilation of text. +@item -trace [events=@var{file}][,file=@var{file}] @findex -trace -Specify a trace file to log output traces to. -This option is available only when using the @var{simple} tracing backend. +Specify tracing options. + +@table @option +@item events=@var{file} +Immediately enable events listed in @var{file}. +The file must contain one event name (as listed in the @var{trace-events} file) +per line. + +This option is only available when using the @var{simple} tracing backend. +@item file=@var{file} +Log output traces to @var{file}. + +This option is only available when using the @var{simple} tracing backend. +@end table ETEXI HXCOMM This is the last statement. Insert new options before this line! diff --git a/trace/control.c b/trace/control.c new file mode 100644 index 00000000000..4c5527d20ad --- /dev/null +++ b/trace/control.c @@ -0,0 +1,42 @@ +/* + * Interface for configuring and controlling the state of tracing events. + * + * Copyright (C) 2011 Lluís Vilanova + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include "trace/control.h" + + +void trace_backend_init_events(const char *fname) +{ + if (fname == NULL) { + return; + } + + FILE *fp = fopen(fname, "r"); + if (!fp) { + fprintf(stderr, "error: could not open trace events file '%s': %s\n", + fname, strerror(errno)); + exit(1); + } + char line_buf[1024]; + while (fgets(line_buf, sizeof(line_buf), fp)) { + size_t len = strlen(line_buf); + if (len > 1) { /* skip empty lines */ + line_buf[len - 1] = '\0'; + if (!trace_event_set_state(line_buf, true)) { + fprintf(stderr, + "error: trace event '%s' does not exist\n", line_buf); + exit(1); + } + } + } + if (fclose(fp) != 0) { + fprintf(stderr, "error: closing file '%s': %s\n", + fname, strerror(errno)); + exit(1); + } +} diff --git a/trace/control.h b/trace/control.h index c99b4d50a8b..2acaa4290e8 100644 --- a/trace/control.h +++ b/trace/control.h @@ -24,10 +24,18 @@ bool trace_event_set_state(const char *name, bool state); /** Initialize the tracing backend. * - * @file Name of trace output file; may be NULL. - * Corresponds to commandline option "-trace file=...". + * @events Name of file with events to be enabled at startup; may be NULL. + * Corresponds to commandline option "-trace events=...". + * @file Name of trace output file; may be NULL. + * Corresponds to commandline option "-trace file=...". * @return Whether the backend could be successfully initialized. */ -bool trace_backend_init(const char *file); +bool trace_backend_init(const char *events, const char *file); + +/** Generic function to initialize the state of events. + * + * @fname Name of file with events to enable; may be NULL. + */ +void trace_backend_init_events(const char *fname); #endif /* TRACE_CONTROL_H */ diff --git a/trace/default.c b/trace/default.c index 3573d5b296d..c9b27a289ba 100644 --- a/trace/default.c +++ b/trace/default.c @@ -25,8 +25,13 @@ bool trace_event_set_state(const char *name, bool state) return false; } -bool trace_backend_init(const char *file) +bool trace_backend_init(const char *events, const char *file) { + if (events) { + fprintf(stderr, "error: -trace events=...: " + "option not supported by the selected tracing backend\n"); + return false; + } if (file) { fprintf(stderr, "error: -trace file=...: " "option not supported by the selected tracing backend\n"); diff --git a/trace/simple.c b/trace/simple.c index 70689e9484a..a6093682dd3 100644 --- a/trace/simple.c +++ b/trace/simple.c @@ -331,7 +331,7 @@ bool trace_event_set_state(const char *name, bool state) return false; } -bool trace_backend_init(const char *file) +bool trace_backend_init(const char *events, const char *file) { pthread_t thread; pthread_attr_t attr; @@ -350,6 +350,7 @@ bool trace_backend_init(const char *file) fprintf(stderr, "warning: unable to initialize simple trace backend\n"); } else { atexit(st_flush_trace_buffer); + trace_backend_init_events(events); st_set_trace_file(file); } diff --git a/vl.c b/vl.c index 60322b62a4e..c6dc6895b43 100644 --- a/vl.c +++ b/vl.c @@ -2137,6 +2137,7 @@ int main(int argc, char **argv, char **envp) .realloc = realloc_and_trace, .free = free_and_trace, }; + const char *trace_events = NULL; const char *trace_file = NULL; atexit(qemu_run_exit_notifiers); @@ -2934,6 +2935,7 @@ int main(int argc, char **argv, char **envp) if (!opts) { exit(1); } + trace_events = qemu_opt_get(opts, "events"); trace_file = qemu_opt_get(opts, "file"); break; } @@ -2994,7 +2996,7 @@ int main(int argc, char **argv, char **envp) set_cpu_log(log_mask); } - if (!trace_backend_init(trace_file)) { + if (!trace_backend_init(trace_events, trace_file)) { exit(1); }