[Qemu-devel] [PATCH 0/2] trace: [*-user] Add commandline arguments to control tracing

[Qemu-devel] [PATCH 0/2] trace: [*-user] Add commandline arguments to control tracing

[Lluís Vilanova]

Adds three commandline arguments to the main *-user programs, following what's
already available in softmmu:

* -trace-enable
* -trace-events
* -trace-file

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---

Lluís Vilanova (2):
      trace: [linux-user] Commandline arguments to control tracing
      trace: [bsd-user] Commandline arguments to control tracing


 bsd-user/main.c   |   21 +++++++++++++++++++++
 linux-user/main.c |   28 ++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)


To: qemu-devel@nongnu.org
Cc: Stefan Hajnoczi <stefanha@redhat.com>

[Qemu-devel] [PATCH 1/2] trace: [linux-user] Commandline arguments to control tracing

[Lluís Vilanova]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 linux-user/main.c |   28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/linux-user/main.c b/linux-user/main.c
index f8a8764..b0d7d2b 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -33,6 +33,7 @@
 #include "qemu/envlist.h"
 #include "elf.h"
 #include "exec/log.h"
+#include "trace/control.h"
 
 char *exec_path;
 
@@ -4000,6 +4001,22 @@ static void handle_arg_version(const char *arg)
     exit(EXIT_SUCCESS);
 }
 
+static void handle_arg_trace_enable(const char *arg)
+{
+    trace_enable_events(arg);
+}
+
+static void handle_arg_trace_events(const char *arg)
+{
+    trace_init_events(arg);
+}
+
+static const char *trace_file = NULL;
+static void handle_arg_trace_file(const char *arg)
+{
+    trace_file = arg;
+}
+
 struct qemu_argument {
     const char *argv;
     const char *env;
@@ -4047,6 +4064,12 @@ static const struct qemu_argument arg_table[] = {
      "",           "log system calls"},
     {"seed",       "QEMU_RAND_SEED",   true,  handle_arg_randseed,
      "",           "Seed for pseudo-random number generator"},
+    {"trace-enable", "QEMU_TRACE_ENABLE",true,  handle_arg_trace_enable,
+     "name",       "enable tracing of specified event names (pass '?' to show a list of events)"},
+    {"trace-events", "QEMU_TRACE_EVENTS",true,  handle_arg_trace_events,
+     "eventsfile", "enable tracing of specified event names (one name/pattern per line)"},
+    {"trace-file", "QEMU_TRACE_FILE",  true,  handle_arg_trace_file,
+     "tracefile",  "output trace file"},
     {"version",    "QEMU_VERSION",     false, handle_arg_version,
      "",           "display version information and exit"},
     {NULL, NULL, false, NULL, NULL, NULL}
@@ -4238,6 +4261,11 @@ int main(int argc, char **argv, char **envp)
 
     optind = parse_args(argc, argv);
 
+    if (!trace_init_backends()) {
+        exit(1);
+    }
+    trace_init_file(trace_file);
+
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
 

Re: [Qemu-devel] [PATCH 1/2] trace: [linux-user] Commandline arguments to control tracing

[Eric Blake]

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On 06/21/2016 07:23 AM, Lluís Vilanova wrote:
> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
> ---
>  linux-user/main.c |   28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 

> +    {"trace-enable", "QEMU_TRACE_ENABLE",true,  handle_arg_trace_enable,
> +     "name",       "enable tracing of specified event names (pass '?' to show a list of events)"},

? is a shell metacharacter, and it requires quoting to be safe against
globbing against any single-letter files in the current directory.  A
better suggestion would be to pass 'help' to show a list of events.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH 1/2] trace: [linux-user] Commandline arguments to control tracing

[Lluís Vilanova]

Eric Blake writes:

> On 06/21/2016 07:23 AM, Lluís Vilanova wrote:
>> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
>> ---
>> linux-user/main.c |   28 ++++++++++++++++++++++++++++
>> 1 file changed, 28 insertions(+)
>> 

>> +    {"trace-enable", "QEMU_TRACE_ENABLE",true,  handle_arg_trace_enable,
>> +     "name",       "enable tracing of specified event names (pass '?' to show a list of events)"},

> ? is a shell metacharacter, and it requires quoting to be safe against
> globbing against any single-letter files in the current directory.  A
> better suggestion would be to pass 'help' to show a list of events.

Right. The code internally uses 'is_help_option()' (also used by "-trace
enable=" and "-cpu" in vl.c), which accepts both '?' and 'help'. I'll just cite
using 'help' (even if both are accepted).

Thanks,
  Lluis

[Qemu-devel] [PATCH 2/2] trace: [bsd-user] Commandline arguments to control tracing

[Lluís Vilanova]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 bsd-user/main.c |   21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/bsd-user/main.c b/bsd-user/main.c
index 9f592be..ce2cc17 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -30,6 +30,7 @@
 #include "qemu/timer.h"
 #include "qemu/envlist.h"
 #include "exec/log.h"
+#include "trace/control.h"
 
 int singlestep;
 unsigned long mmap_min_addr;
@@ -687,6 +688,14 @@ static void usage(void)
            "-p pagesize       set the host page size to 'pagesize'\n"
            "-singlestep       always run in singlestep mode\n"
            "-strace           log system calls\n"
+           "-trace-enable name\n"
+           "                  enable tracing of specified event names\n"
+           "                  (pass '?' to show a list of events)\n"
+           "-trace-events eventsfile\n"
+           "                  enable tracing of specified event names\n"
+           "                  (one name/pattern per line)\n"
+           "-trace-file tracefile\n"
+           "                  output trace file\n"
            "\n"
            "Environment variables:\n"
            "QEMU_STRACE       Print system calls and arguments similar to the\n"
@@ -735,6 +744,7 @@ int main(int argc, char **argv)
     int gdbstub_port = 0;
     char **target_environ, **wrk;
     envlist_t *envlist = NULL;
+    const char *trace_file = NULL;
     bsd_type = target_openbsd;
 
     if (argc <= 1)
@@ -840,6 +850,12 @@ int main(int argc, char **argv)
             singlestep = 1;
         } else if (!strcmp(r, "strace")) {
             do_strace = 1;
+        } else if (!strcmp(r, "trace-enable")) {
+            trace_enable_events(argv[optind++]);
+        } else if (!strcmp(r, "trace-events")) {
+            trace_init_events(argv[optind++]);
+        } else if (!strcmp(r, "trace-file")) {
+            trace_file = argv[optind++];
         } else
         {
             usage();
@@ -865,6 +881,11 @@ int main(int argc, char **argv)
     }
     filename = argv[optind];
 
+    if (!trace_init_backends()) {
+        exit(1);
+    }
+    trace_init_file(trace_file);
+
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
 

Re: [Qemu-devel] [PATCH 2/2] trace: [bsd-user] Commandline arguments to control tracing

[Eric Blake]

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On 06/21/2016 07:23 AM, Lluís Vilanova wrote:
> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
> ---
>  bsd-user/main.c |   21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/bsd-user/main.c b/bsd-user/main.c
> index 9f592be..ce2cc17 100644
> --- a/bsd-user/main.c
> +++ b/bsd-user/main.c
> @@ -30,6 +30,7 @@
>  #include "qemu/timer.h"
>  #include "qemu/envlist.h"
>  #include "exec/log.h"
> +#include "trace/control.h"
>  
>  int singlestep;
>  unsigned long mmap_min_addr;
> @@ -687,6 +688,14 @@ static void usage(void)
>             "-p pagesize       set the host page size to 'pagesize'\n"
>             "-singlestep       always run in singlestep mode\n"
>             "-strace           log system calls\n"
> +           "-trace-enable name\n"
> +           "                  enable tracing of specified event names\n"
> +           "                  (pass '?' to show a list of events)\n"

Same complaint as in 1/2.  Also, why does this one split into two lines,
while that one had long lines?

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH 2/2] trace: [bsd-user] Commandline arguments to control tracing

[Lluís Vilanova]

Eric Blake writes:

> On 06/21/2016 07:23 AM, Lluís Vilanova wrote:
>> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
>> ---
>> bsd-user/main.c |   21 +++++++++++++++++++++
>> 1 file changed, 21 insertions(+)
>> 
>> diff --git a/bsd-user/main.c b/bsd-user/main.c
>> index 9f592be..ce2cc17 100644
>> --- a/bsd-user/main.c
>> +++ b/bsd-user/main.c
>> @@ -30,6 +30,7 @@
>> #include "qemu/timer.h"
>> #include "qemu/envlist.h"
>> #include "exec/log.h"
>> +#include "trace/control.h"
>> 
>> int singlestep;
>> unsigned long mmap_min_addr;
>> @@ -687,6 +688,14 @@ static void usage(void)
>> "-p pagesize       set the host page size to 'pagesize'\n"
>> "-singlestep       always run in singlestep mode\n"
>> "-strace           log system calls\n"
>> +           "-trace-enable name\n"
>> +           "                  enable tracing of specified event names\n"
>> +           "                  (pass '?' to show a list of events)\n"

> Same complaint as in 1/2.  Also, why does this one split into two lines,
> while that one had long lines?

An oversight on my side.

Thanks,
  Lluis