Re: [PATCH v15 11/18] trace-cmd: Exchange tracing IDs between host and guest

[Slavomir Kaslev <slavomir.kaslev@gmail.com>]

On Thu, Nov 28, 2019 at 11:01 AM Tzvetomir Stoyanov (VMware)
<tz.stoyanov@gmail.com> wrote:

[...]

> diff --git a/tracecmd/trace-agent.c b/tracecmd/trace-agent.c
> index 1c6e0a3..cc330b7 100644
> --- a/tracecmd/trace-agent.c
> +++ b/tracecmd/trace-agent.c
> @@ -128,6 +128,7 @@ cleanup:
>  static void agent_handle(int sd, int nr_cpus, int page_size)
>  {
>         struct tracecmd_msg_handle *msg_handle;
> +       unsigned long long trace_id;
>         unsigned int *ports;
>         char **argv = NULL;
>         int argc = 0;
> @@ -144,7 +145,8 @@ static void agent_handle(int sd, int nr_cpus, int page_size)
>         if (!msg_handle)
>                 die("Failed to allocate message handle");
>
> -       ret = tracecmd_msg_recv_trace_req(msg_handle, &argc, &argv, &use_fifos);
> +       ret = tracecmd_msg_recv_trace_req(msg_handle, &argc, &argv,
> +                                         &use_fifos, &trace_id);

Why is `tracecmd_msg_recv_trace_req` receiving trace_id if it's
getting generated by the agent below?

>         if (ret < 0)
>                 die("Failed to receive trace request");
>
> @@ -153,13 +155,13 @@ static void agent_handle(int sd, int nr_cpus, int page_size)
>
>         if (!use_fifos)
>                 make_vsocks(nr_cpus, fds, ports);
> -
> +       trace_id = tracecmd_generate_traceid();
>         ret = tracecmd_msg_send_trace_resp(msg_handle, nr_cpus, page_size,
> -                                          ports, use_fifos);
> +                                          ports, use_fifos, trace_id);
>         if (ret < 0)
>                 die("Failed to send trace response");
> -
> -       trace_record_agent(msg_handle, nr_cpus, fds, argc, argv, use_fifos);
> +       trace_record_agent(msg_handle, nr_cpus, fds, argc, argv,
> +                          use_fifos, trace_id);
>
>         free(argv[0]);
>         free(argv);

Cheers,

-- Slavi