return &session->machines.host;
 }
 
+static int deliver_sample_value(struct perf_session *session,
+                               struct perf_tool *tool,
+                               union perf_event *event,
+                               struct perf_sample *sample,
+                               struct sample_read_value *v,
+                               struct machine *machine)
+{
+       struct perf_sample_id *sid;
+
+       sid = perf_evlist__id2sid(session->evlist, v->id);
+       if (sid) {
+               sample->id     = v->id;
+               sample->period = v->value - sid->period;
+               sid->period    = v->value;
+       }
+
+       if (!sid || sid->evsel == NULL) {
+               ++session->stats.nr_unknown_id;
+               return 0;
+       }
+
+       return tool->sample(tool, event, sample, sid->evsel, machine);
+}
+
+static int deliver_sample_group(struct perf_session *session,
+                               struct perf_tool *tool,
+                               union  perf_event *event,
+                               struct perf_sample *sample,
+                               struct machine *machine)
+{
+       int ret = -EINVAL;
+       u64 i;
+
+       for (i = 0; i < sample->read.group.nr; i++) {
+               ret = deliver_sample_value(session, tool, event, sample,
+                                          &sample->read.group.values[i],
+                                          machine);
+               if (ret)
+                       break;
+       }
+
+       return ret;
+}
+
+static int
+perf_session__deliver_sample(struct perf_session *session,
+                            struct perf_tool *tool,
+                            union  perf_event *event,
+                            struct perf_sample *sample,
+                            struct perf_evsel *evsel,
+                            struct machine *machine)
+{
+       /* We know evsel != NULL. */
+       u64 sample_type = evsel->attr.sample_type;
+       u64 read_format = evsel->attr.read_format;
+
+       /* Standard sample delievery. */
+       if (!(sample_type & PERF_SAMPLE_READ))
+               return tool->sample(tool, event, sample, evsel, machine);
+
+       /* For PERF_SAMPLE_READ we have either single or group mode. */
+       if (read_format & PERF_FORMAT_GROUP)
+               return deliver_sample_group(session, tool, event, sample,
+                                           machine);
+       else
+               return deliver_sample_value(session, tool, event, sample,
+                                           &sample->read.one, machine);
+}
+
 static int perf_session_deliver_event(struct perf_session *session,
                                      union perf_event *event,
                                      struct perf_sample *sample,
                        ++session->stats.nr_unprocessable_samples;
                        return 0;
                }
-               return tool->sample(tool, event, sample, evsel, machine);
+               return perf_session__deliver_sample(session, tool, event,
+                                                   sample, evsel, machine);
        case PERF_RECORD_MMAP:
                return tool->mmap(tool, event, sample, machine);
        case PERF_RECORD_COMM: