[Qemu-devel] [PATCH v8 0/7] trace: enable tracing in qemu-io/qemu-nbd/qemu-img

[Qemu-devel] [PATCH v8 0/7] trace: enable tracing in qemu-io/qemu-nbd/qemu-img

[Denis V. Lunev]

Changes from v6:
- changed order of patches 1 & 2

Changes from v5:
- added missed hunk into patch #7

Changes from v4:
- synced help descriprion for --trace with man for qemu.1/qemu-img.1/qemu-nbd.8
- moved @findex from qemu-option-trace.texi

Changes from v3:
- fixed difference in help/man for qemu-img/qemu-nbd
- created separate .texi to contain trace description, proper dependency is
  added to makefile
- added --version/--help description to qemu-img
- fixed crash induced by new option processing scheme in qemu-img which
has happened when invoked as './qemu-img -K'

Changes from v2:
- tweaked man-pages of qemu-nbd/qemu-img
- added support for qemu-img (patches 4-5 as suggested)

Changes from v1:
- fixed nits found by Eric

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>

Denis V. Lunev (7):
  doc: sync help descriprion for --trace with man for qemu.1
  doc: move text describing --trace to specific .texi file
  trace: move qemu_trace_opts to trace/control.c
  trace: enable tracing in qemu-io
  trace: enable tracing in qemu-nbd
  qemu-img: move common options parsing before commands processing
  trace: enable tracing in qemu-img

 Makefile               |  7 ++++---
 qemu-img.c             | 55 ++++++++++++++++++++++++++++++++++++++------------
 qemu-img.texi          | 13 +++++++++++-
 qemu-io.c              | 17 ++++++++++++----
 qemu-nbd.c             | 18 ++++++++++++++++-
 qemu-nbd.texi          |  3 +++
 qemu-option-trace.texi | 25 +++++++++++++++++++++++
 qemu-options.hx        | 29 ++------------------------
 trace/control.c        | 44 +++++++++++++++++++++++++++++++++++++++-
 trace/control.h        | 24 ++++++++++++----------
 vl.c                   | 37 +--------------------------------
 11 files changed, 175 insertions(+), 97 deletions(-)
 create mode 100644 qemu-option-trace.texi

-- 
2.1.4

[Qemu-devel] [PATCH 1/7] doc: sync help descriprion for --trace with man for qemu.1

[Denis V. Lunev]

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 qemu-options.hx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/qemu-options.hx b/qemu-options.hx
index 17f15ad..07e4a03 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3669,7 +3669,7 @@ DEF("trace", HAS_ARG, QEMU_OPTION_trace,
 STEXI
 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}]
+@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
 @findex -trace
 
 Specify tracing options.
-- 
2.1.4

[Qemu-devel] [PATCH 2/7] doc: move text describing --trace to specific .texi file

[Denis V. Lunev]

This text will be included to qemu-nbd/qemu-img mans in the next patches.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 Makefile               |  3 ++-
 qemu-option-trace.texi | 25 +++++++++++++++++++++++++
 qemu-options.hx        | 27 +--------------------------
 3 files changed, 28 insertions(+), 27 deletions(-)
 create mode 100644 qemu-option-trace.texi

diff --git a/Makefile b/Makefile
index 53e4119..b56e11d 100644
--- a/Makefile
+++ b/Makefile
@@ -564,6 +564,7 @@ qemu.1: qemu-doc.texi qemu-options.texi qemu-monitor.texi qemu-monitor-info.texi
 	  perl -Ww -- $(SRC_PATH)/scripts/texi2pod.pl $< qemu.pod && \
 	  $(POD2MAN) --section=1 --center=" " --release=" " qemu.pod > $@, \
 	  "  GEN   $@")
+qemu.1: qemu-option-trace.texi
 
 qemu-img.1: qemu-img.texi qemu-img-cmds.texi
 	$(call quiet-command, \
@@ -595,7 +596,7 @@ info: qemu-doc.info qemu-tech.info
 pdf: qemu-doc.pdf qemu-tech.pdf
 
 qemu-doc.dvi qemu-doc.html qemu-doc.info qemu-doc.pdf: \
-	qemu-img.texi qemu-nbd.texi qemu-options.texi \
+	qemu-img.texi qemu-nbd.texi qemu-options.texi qemu-option-trace.texi \
 	qemu-monitor.texi qemu-img-cmds.texi qemu-ga.texi \
 	qemu-monitor-info.texi
 
diff --git a/qemu-option-trace.texi b/qemu-option-trace.texi
new file mode 100644
index 0000000..0296ca6
--- /dev/null
+++ b/qemu-option-trace.texi
@@ -0,0 +1,25 @@
+Specify tracing options.
+
+@table @option
+@item [enable=]@var{pattern}
+Immediately enable events matching @var{pattern}.
+The file must contain one event name (as listed in the @file{trace-events} file)
+per line; globbing patterns are accepted too.  This option is only
+available if QEMU has been compiled with the @var{simple}, @var{stderr}
+or @var{ftrace} tracing backend.  To specify multiple events or patterns,
+specify the @option{-trace} option multiple times.
+
+Use @code{-trace help} to print a list of names of trace points.
+
+@item events=@var{file}
+Immediately enable events listed in @var{file}.
+The file must contain one event name (as listed in the @file{trace-events} file)
+per line; globbing patterns are accepted too.  This option is only
+available if QEMU has been compiled with the @var{simple}, @var{stderr} or
+@var{ftrace} tracing backend.
+
+@item file=@var{file}
+Log output traces to @var{file}.
+This option is only available if QEMU has been compiled with
+the @var{simple} tracing backend.
+@end table
diff --git a/qemu-options.hx b/qemu-options.hx
index 07e4a03..a95a936 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3671,32 +3671,7 @@ 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 [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
 @findex -trace
-
-Specify tracing options.
-
-@table @option
-@item [enable=]@var{pattern}
-Immediately enable events matching @var{pattern}.
-The file must contain one event name (as listed in the @file{trace-events} file)
-per line; globbing patterns are accepted too.  This option is only
-available if QEMU has been compiled with the @var{simple}, @var{stderr}
-or @var{ftrace} tracing backend.  To specify multiple events or patterns,
-specify the @option{-trace} option multiple times.
-
-Use @code{-trace help} to print a list of names of trace points.
-
-@item events=@var{file}
-Immediately enable events listed in @var{file}.
-The file must contain one event name (as listed in the @file{trace-events} file)
-per line; globbing patterns are accepted too.  This option is only
-available if QEMU has been compiled with the @var{simple}, @var{stderr} or
-@var{ftrace} tracing backend.
-
-@item file=@var{file}
-Log output traces to @var{file}.
-This option is only available if QEMU has been compiled with
-the @var{simple} tracing backend.
-@end table
+@include qemu-option-trace.texi
 ETEXI
 
 HXCOMM Internal use
-- 
2.1.4

[Qemu-devel] [PATCH 3/7] trace: move qemu_trace_opts to trace/control.c

[Denis V. Lunev]

The patch also creates trace_opt_parse() helper in trace/control.c to reuse
this code in next patches for qemu-nbd and qemu-io.

The patch also makes trace_init_events() static, as this call is not used
outside the module anymore.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 trace/control.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
 trace/control.h | 24 +++++++++++++-----------
 vl.c            | 37 +------------------------------------
 3 files changed, 57 insertions(+), 48 deletions(-)

diff --git a/trace/control.c b/trace/control.c
index d099f73..75fc731 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -20,11 +20,33 @@
 #include "qemu/log.h"
 #endif
 #include "qemu/error-report.h"
+#include "qemu/config-file.h"
 #include "monitor/monitor.h"
 
 int trace_events_enabled_count;
 bool trace_events_dstate[TRACE_EVENT_COUNT];
 
+QemuOptsList qemu_trace_opts = {
+    .name = "trace",
+    .implied_opt_name = "enable",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
+    .desc = {
+        {
+            .name = "enable",
+            .type = QEMU_OPT_STRING,
+        },
+        {
+            .name = "events",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "file",
+            .type = QEMU_OPT_STRING,
+        },
+        { /* end of list */ }
+    },
+};
+
+
 TraceEvent *trace_event_name(const char *name)
 {
     assert(name != NULL);
@@ -141,7 +163,7 @@ void trace_enable_events(const char *line_buf)
     }
 }
 
-void trace_init_events(const char *fname)
+static void trace_init_events(const char *fname)
 {
     Location loc;
     FILE *fp;
@@ -216,3 +238,23 @@ bool trace_init_backends(void)
 
     return true;
 }
+
+char *trace_opt_parse(const char *optarg, char *trace_file)
+{
+    QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
+                                             optarg, true);
+    if (!opts) {
+        exit(1);
+    }
+    if (qemu_opt_get(opts, "enable")) {
+        trace_enable_events(qemu_opt_get(opts, "enable"));
+    }
+    trace_init_events(qemu_opt_get(opts, "events"));
+    if (trace_file) {
+        g_free(trace_file);
+    }
+    trace_file = g_strdup(qemu_opt_get(opts, "file"));
+    qemu_opts_del(opts);
+
+    return trace_file;
+}
diff --git a/trace/control.h b/trace/control.h
index e2ba6d4..942f9f5 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -160,17 +160,6 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 bool trace_init_backends(void);
 
 /**
- * trace_init_events:
- * @events: Name of file with events to be enabled at startup; may be NULL.
- *          Corresponds to commandline option "-trace events=...".
- *
- * Read the list of enabled tracing events.
- *
- * Returns: Whether the backends could be successfully initialized.
- */
-void trace_init_events(const char *file);
-
-/**
  * trace_init_file:
  * @file:   Name of trace output file; may be NULL.
  *          Corresponds to commandline option "-trace file=...".
@@ -197,6 +186,19 @@ void trace_list_events(void);
  */
 void trace_enable_events(const char *line_buf);
 
+/**
+ * Definition of QEMU options describing trace subsystem configuration
+ */
+extern QemuOptsList qemu_trace_opts;
+
+/**
+ * trace_opt_parse:
+ * @optarg: A string argument of --trace command line argument
+ * @trace_file: current filename to save traces to
+ *
+ * Initialize tracing subsystem.
+ */
+char *trace_opt_parse(const char *optarg, char *trace_file);
 
 #include "trace/control-internal.h"
 
diff --git a/vl.c b/vl.c
index 0736d84..0aadff2 100644
--- a/vl.c
+++ b/vl.c
@@ -262,26 +262,6 @@ static QemuOptsList qemu_sandbox_opts = {
     },
 };
 
-static QemuOptsList qemu_trace_opts = {
-    .name = "trace",
-    .implied_opt_name = "enable",
-    .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
-    .desc = {
-        {
-            .name = "enable",
-            .type = QEMU_OPT_STRING,
-        },
-        {
-            .name = "events",
-            .type = QEMU_OPT_STRING,
-        },{
-            .name = "file",
-            .type = QEMU_OPT_STRING,
-        },
-        { /* end of list */ }
-    },
-};
-
 static QemuOptsList qemu_option_rom_opts = {
     .name = "option-rom",
     .implied_opt_name = "romfile",
@@ -3866,23 +3846,8 @@ int main(int argc, char **argv, char **envp)
                 xen_mode = XEN_ATTACH;
                 break;
             case QEMU_OPTION_trace:
-            {
-                opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
-                                               optarg, true);
-                if (!opts) {
-                    exit(1);
-                }
-                if (qemu_opt_get(opts, "enable")) {
-                    trace_enable_events(qemu_opt_get(opts, "enable"));
-                }
-                trace_init_events(qemu_opt_get(opts, "events"));
-                if (trace_file) {
-                    g_free(trace_file);
-                }
-                trace_file = g_strdup(qemu_opt_get(opts, "file"));
-                qemu_opts_del(opts);
+                trace_file = trace_opt_parse(optarg, trace_file);
                 break;
-            }
             case QEMU_OPTION_readconfig:
                 {
                     int ret = qemu_read_config_file(optarg);
-- 
2.1.4

[Qemu-devel] [PATCH 4/7] trace: enable tracing in qemu-io

[Denis V. Lunev]

Moving trace_init_backends() into trace_opt_parse() is not possible. This
should be called after daemonize() in vl.c.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 qemu-io.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index d977a6e..0ef28b0 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -18,6 +18,7 @@
 #include "qemu/option.h"
 #include "qemu/config-file.h"
 #include "qemu/readline.h"
+#include "qemu/log.h"
 #include "qapi/qmp/qstring.h"
 #include "qom/object_interfaces.h"
 #include "sysemu/block-backend.h"
@@ -253,7 +254,9 @@ static void usage(const char *name)
 "  -k, --native-aio     use kernel AIO implementation (on Linux only)\n"
 "  -t, --cache=MODE     use the given cache mode for the image\n"
 "  -d, --discard=MODE   use the given discard mode for the image\n"
-"  -T, --trace FILE     enable trace events listed in the given file\n"
+"  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
+"                       specify tracing options\n"
+"                       see qemu-img(1) man page for full description\n"
 "  -h, --help           display this help and exit\n"
 "  -V, --version        output version information and exit\n"
 "\n"
@@ -458,6 +461,7 @@ int main(int argc, char **argv)
     Error *local_error = NULL;
     QDict *opts = NULL;
     const char *format = NULL;
+    char *trace_file = NULL;
 
 #ifdef CONFIG_POSIX
     signal(SIGPIPE, SIG_IGN);
@@ -470,6 +474,7 @@ int main(int argc, char **argv)
 
     module_call_init(MODULE_INIT_QOM);
     qemu_add_opts(&qemu_object_opts);
+    qemu_add_opts(&qemu_trace_opts);
     bdrv_init();
 
     while ((c = getopt_long(argc, argv, sopt, lopt, &opt_index)) != -1) {
@@ -509,9 +514,7 @@ int main(int argc, char **argv)
             }
             break;
         case 'T':
-            if (!trace_init_backends()) {
-                exit(1); /* error message will have been printed */
-            }
+            trace_file = trace_opt_parse(optarg, trace_file);
             break;
         case 'V':
             printf("%s version %s\n", progname, QEMU_VERSION);
@@ -557,6 +560,12 @@ int main(int argc, char **argv)
         exit(1);
     }
 
+    if (!trace_init_backends()) {
+        exit(1);
+    }
+    trace_init_file(trace_file);
+    qemu_set_log(LOG_TRACE);
+
     /* initialize commands */
     qemuio_add_command(&quit_cmd);
     qemuio_add_command(&open_cmd);
-- 
2.1.4

[Qemu-devel] [PATCH 5/7] trace: enable tracing in qemu-nbd

[Denis V. Lunev]

Please note, trace_init_backends() must be called in the final process,
i.e. after daemonization. This is necessary to keep tracing thread in
the proper process.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 Makefile      |  2 +-
 qemu-nbd.c    | 18 +++++++++++++++++-
 qemu-nbd.texi |  3 +++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index b56e11d..f9d369b 100644
--- a/Makefile
+++ b/Makefile
@@ -578,7 +578,7 @@ fsdev/virtfs-proxy-helper.1: fsdev/virtfs-proxy-helper.texi
 	  $(POD2MAN) --section=1 --center=" " --release=" " fsdev/virtfs-proxy-helper.pod > $@, \
 	  "  GEN   $@")
 
-qemu-nbd.8: qemu-nbd.texi
+qemu-nbd.8: qemu-nbd.texi qemu-option-trace.texi
 	$(call quiet-command, \
 	  perl -Ww -- $(SRC_PATH)/scripts/texi2pod.pl $< qemu-nbd.pod && \
 	  $(POD2MAN) --section=8 --center=" " --release=" " qemu-nbd.pod > $@, \
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 9519db3..2aaffc9 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -27,12 +27,14 @@
 #include "qemu/error-report.h"
 #include "qemu/config-file.h"
 #include "qemu/bswap.h"
+#include "qemu/log.h"
 #include "block/snapshot.h"
 #include "qapi/util.h"
 #include "qapi/qmp/qstring.h"
 #include "qom/object_interfaces.h"
 #include "io/channel-socket.h"
 #include "crypto/init.h"
+#include "trace/control.h"
 
 #include <getopt.h>
 #include <libgen.h>
@@ -88,6 +90,8 @@ static void usage(const char *name)
 "General purpose options:\n"
 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
 "                            passwords and/or encryption keys\n"
+"  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
+"                            specify tracing options\n"
 #ifdef __linux__
 "Kernel NBD client support:\n"
 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
@@ -470,7 +474,7 @@ int main(int argc, char **argv)
     off_t fd_size;
     QemuOpts *sn_opts = NULL;
     const char *sn_id_or_name = NULL;
-    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
+    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:";
     struct option lopt[] = {
         { "help", no_argument, NULL, 'h' },
         { "version", no_argument, NULL, 'V' },
@@ -498,6 +502,7 @@ int main(int argc, char **argv)
         { "export-name", required_argument, NULL, 'x' },
         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
+        { "trace", required_argument, NULL, 'T' },
         { NULL, 0, NULL, 0 }
     };
     int ch;
@@ -518,6 +523,7 @@ int main(int argc, char **argv)
     const char *tlscredsid = NULL;
     bool imageOpts = false;
     bool writethrough = true;
+    char *trace_file = NULL;
 
     /* The client thread uses SIGTERM to interrupt the server.  A signal
      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
@@ -531,6 +537,7 @@ int main(int argc, char **argv)
 
     module_call_init(MODULE_INIT_QOM);
     qemu_add_opts(&qemu_object_opts);
+    qemu_add_opts(&qemu_trace_opts);
     qemu_init_exec_dir(argv[0]);
 
     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
@@ -703,6 +710,9 @@ int main(int argc, char **argv)
         case QEMU_NBD_OPT_IMAGE_OPTS:
             imageOpts = true;
             break;
+        case 'T':
+            trace_file = trace_opt_parse(optarg, trace_file);
+            break;
         }
     }
 
@@ -718,6 +728,12 @@ int main(int argc, char **argv)
         exit(EXIT_FAILURE);
     }
 
+    if (!trace_init_backends()) {
+        exit(1);
+    }
+    trace_init_file(trace_file);
+    qemu_set_log(LOG_TRACE);
+
     if (tlscredsid) {
         if (sockpath) {
             error_report("TLS is only supported with IPv4/IPv6");
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 9f23343..91ebf04 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -92,6 +92,9 @@ Display extra debugging information
 Display this help and exit
 @item -V, --version
 Display version information and exit
+@item -T, --trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
+@findex --trace
+@include qemu-option-trace.texi
 @end table
 
 @c man end
-- 
2.1.4

[Qemu-devel] [PATCH 6/7] qemu-img: move common options parsing before commands processing

[Denis V. Lunev]

This is necessary to enable creation of common qemu-img options which will
be specified before command.

The patch also enables '-V' alias to '--version' (exactly like in other
block utilities) and documents this change.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 qemu-img.c    | 39 ++++++++++++++++++++++++++-------------
 qemu-img.texi | 10 +++++++++-
 2 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 14e2661..2194c2d 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -91,9 +91,12 @@ static void QEMU_NORETURN help(void)
 {
     const char *help_msg =
            QEMU_IMG_VERSION
-           "usage: qemu-img command [command options]\n"
+           "usage: qemu-img [standard options] command [command options]\n"
            "QEMU disk image utility\n"
            "\n"
+           "    '-h', '--help'       display this help and exit\n"
+           "    '-V', '--version'    output version information and exit\n"
+           "\n"
            "Command syntax:\n"
 #define DEF(option, callback, arg_string)        \
            "  " arg_string "\n"
@@ -3806,7 +3809,7 @@ int main(int argc, char **argv)
     int c;
     static const struct option long_options[] = {
         {"help", no_argument, 0, 'h'},
-        {"version", no_argument, 0, 'v'},
+        {"version", no_argument, 0, 'V'},
         {0, 0, 0, 0}
     };
 
@@ -3829,27 +3832,37 @@ int main(int argc, char **argv)
     if (argc < 2) {
         error_exit("Not enough arguments");
     }
-    cmdname = argv[1];
 
     qemu_add_opts(&qemu_object_opts);
     qemu_add_opts(&qemu_source_opts);
 
-    /* find the command */
-    for (cmd = img_cmds; cmd->name != NULL; cmd++) {
-        if (!strcmp(cmdname, cmd->name)) {
-            return cmd->handler(argc - 1, argv + 1);
+    while ((c = getopt_long(argc, argv, "+hV", long_options, NULL)) != -1) {
+        switch (c) {
+        case 'h':
+            help();
+            return 0;
+        case 'V':
+            printf(QEMU_IMG_VERSION);
+            return 0;
         }
     }
 
-    c = getopt_long(argc, argv, "h", long_options, NULL);
+    cmdname = argv[optind];
 
-    if (c == 'h') {
-        help();
-    }
-    if (c == 'v') {
-        printf(QEMU_IMG_VERSION);
+    /* reset getopt_long scanning */
+    argc -= optind;
+    if (argc < 1) {
         return 0;
     }
+    argv += optind;
+    optind = 1;
+
+    /* find the command */
+    for (cmd = img_cmds; cmd->name != NULL; cmd++) {
+        if (!strcmp(cmdname, cmd->name)) {
+            return cmd->handler(argc, argv);
+        }
+    }
 
     /* not found */
     error_exit("Command not found: %s", cmdname);
diff --git a/qemu-img.texi b/qemu-img.texi
index cbe50e9..f1b874d 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -1,6 +1,6 @@
 @example
 @c man begin SYNOPSIS
-@command{qemu-img} @var{command} [@var{command} @var{options}]
+@command{qemu-img} [@var{standard} @var{options}] @var{command} [@var{command} @var{options}]
 @c man end
 @end example
 
@@ -16,6 +16,14 @@ inconsistent state.
 
 @c man begin OPTIONS
 
+Standard options:
+@table @option
+@item -h, --help
+Display this help and exit
+@item -V, --version
+Display version information and exit
+@end table
+
 The following commands are supported:
 
 @include qemu-img-cmds.texi
-- 
2.1.4

[Qemu-devel] [PATCH 7/7] trace: enable tracing in qemu-img

[Denis V. Lunev]

The command will work this way:
    qemu-img --trace qcow2* create -f qcow2 1.img 64G

Signed-off-by: Denis V. Lunev <den@openvz.org>
Suggested by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
---
 Makefile      |  2 +-
 qemu-img.c    | 18 +++++++++++++++++-
 qemu-img.texi |  3 +++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index f9d369b..2b00a37 100644
--- a/Makefile
+++ b/Makefile
@@ -566,7 +566,7 @@ qemu.1: qemu-doc.texi qemu-options.texi qemu-monitor.texi qemu-monitor-info.texi
 	  "  GEN   $@")
 qemu.1: qemu-option-trace.texi
 
-qemu-img.1: qemu-img.texi qemu-img-cmds.texi
+qemu-img.1: qemu-img.texi qemu-option-trace.texi qemu-img-cmds.texi
 	$(call quiet-command, \
 	  perl -Ww -- $(SRC_PATH)/scripts/texi2pod.pl $< qemu-img.pod && \
 	  $(POD2MAN) --section=1 --center=" " --release=" " qemu-img.pod > $@, \
diff --git a/qemu-img.c b/qemu-img.c
index 2194c2d..0b013f2 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -32,6 +32,7 @@
 #include "qemu/config-file.h"
 #include "qemu/option.h"
 #include "qemu/error-report.h"
+#include "qemu/log.h"
 #include "qom/object_interfaces.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/block-backend.h"
@@ -39,6 +40,7 @@
 #include "block/blockjob.h"
 #include "block/qapi.h"
 #include "crypto/init.h"
+#include "trace/control.h"
 #include <getopt.h>
 
 #define QEMU_IMG_VERSION "qemu-img version " QEMU_VERSION QEMU_PKGVERSION \
@@ -96,6 +98,8 @@ static void QEMU_NORETURN help(void)
            "\n"
            "    '-h', '--help'       display this help and exit\n"
            "    '-V', '--version'    output version information and exit\n"
+           "    '-T', '--trace'      [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
+           "                         specify tracing options\n"
            "\n"
            "Command syntax:\n"
 #define DEF(option, callback, arg_string)        \
@@ -3806,10 +3810,12 @@ int main(int argc, char **argv)
     const img_cmd_t *cmd;
     const char *cmdname;
     Error *local_error = NULL;
+    char *trace_file = NULL;
     int c;
     static const struct option long_options[] = {
         {"help", no_argument, 0, 'h'},
         {"version", no_argument, 0, 'V'},
+        {"trace", required_argument, NULL, 'T'},
         {0, 0, 0, 0}
     };
 
@@ -3835,8 +3841,9 @@ int main(int argc, char **argv)
 
     qemu_add_opts(&qemu_object_opts);
     qemu_add_opts(&qemu_source_opts);
+    qemu_add_opts(&qemu_trace_opts);
 
-    while ((c = getopt_long(argc, argv, "+hV", long_options, NULL)) != -1) {
+    while ((c = getopt_long(argc, argv, "+hVT:", long_options, NULL)) != -1) {
         switch (c) {
         case 'h':
             help();
@@ -3844,6 +3851,9 @@ int main(int argc, char **argv)
         case 'V':
             printf(QEMU_IMG_VERSION);
             return 0;
+        case 'T':
+            trace_file = trace_opt_parse(optarg, trace_file);
+            break;
         }
     }
 
@@ -3857,6 +3867,12 @@ int main(int argc, char **argv)
     argv += optind;
     optind = 1;
 
+    if (!trace_init_backends()) {
+        exit(1);
+    }
+    trace_init_file(trace_file);
+    qemu_set_log(LOG_TRACE);
+
     /* find the command */
     for (cmd = img_cmds; cmd->name != NULL; cmd++) {
         if (!strcmp(cmdname, cmd->name)) {
diff --git a/qemu-img.texi b/qemu-img.texi
index f1b874d..449a19c 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -22,6 +22,9 @@ Standard options:
 Display this help and exit
 @item -V, --version
 Display version information and exit
+@item -T, --trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
+@findex --trace
+@include qemu-option-trace.texi
 @end table
 
 The following commands are supported:
-- 
2.1.4