perf tools: Add feature header record to pipe-mode

Add header record types to pipe-mode, reusing the functions
used in file-mode and leveraging the new struct feat_fd.

For alignment, check that synthesized events don't exceed
pagesize.

Add the perf_event__synthesize_feature event call back to
process the new header records.

Before this patch:

  $ perf record -o - -e cycles sleep 1 | perf report --stdio --header
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  ...

After this patch:
  $ perf record -o - -e cycles sleep 1 | perf report --stdio --header
  # ========
  # captured on: Mon May 22 16:33:43 2017
  # ========
  #
  # hostname : my_hostname
  # os release : 4.11.0-dbx-up_perf
  # perf version : 4.11.rc6.g6277c80
  # arch : x86_64
  # nrcpus online : 72
  # nrcpus avail : 72
  # cpudesc : Intel(R) Xeon(R) CPU E5-2696 v3 @ 2.30GHz
  # cpuid : GenuineIntel,6,63,2
  # total memory : 263457192 kB
  # cmdline : /root/perf record -o - -e cycles -c 100000 sleep 1
  # HEADER_CPU_TOPOLOGY info available, use -I to display
  # HEADER_NUMA_TOPOLOGY info available, use -I to display
  # pmu mappings: intel_bts = 6, uncore_imc_4 = 22, uncore_sbox_1 = 47, uncore_cbox_5 = 33, uncore_ha_0 = 16, uncore_cbox
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  ...

Support added for the subcommands: report, inject, annotate and script.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170718042549.145161-16-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/header.c

@@ -35,6 +35,7 @@
 #include "data.h"
 #include <api/fs/fs.h>
 #include "asm/bug.h"
+#include "tool.h"
 
 #include "sane_ctype.h"
 
@@ -2982,6 +2983,103 @@ int perf_event__synthesize_attr(struct perf_tool *tool,
 	return err;
 }
 
+int perf_event__synthesize_features(struct perf_tool *tool,
+				    struct perf_session *session,
+				    struct perf_evlist *evlist,
+				    perf_event__handler_t process)
+{
+	struct perf_header *header = &session->header;
+	struct feat_fd ff;
+	struct feature_event *fe;
+	size_t sz, sz_hdr;
+	int feat, ret;
+
+	sz_hdr = sizeof(fe->header);
+	sz = sizeof(union perf_event);
+	/* get a nice alignment */
+	sz = PERF_ALIGN(sz, page_size);
+
+	memset(&ff, 0, sizeof(ff));
+
+	ff.buf = malloc(sz);
+	if (!ff.buf)
+		return -ENOMEM;
+
+	ff.size = sz - sz_hdr;
+
+	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
+		if (!feat_ops[feat].synthesize) {
+			pr_debug("No record header feature for header :%d\n", feat);
+			continue;
+		}
+
+		ff.offset = sizeof(*fe);
+
+		ret = feat_ops[feat].write(&ff, evlist);
+		if (ret || ff.offset <= (ssize_t)sizeof(*fe)) {
+			pr_debug("Error writing feature\n");
+			continue;
+		}
+		/* ff.buf may have changed due to realloc in do_write() */
+		fe = ff.buf;
+		memset(fe, 0, sizeof(*fe));
+
+		fe->feat_id = feat;
+		fe->header.type = PERF_RECORD_HEADER_FEATURE;
+		fe->header.size = ff.offset;
+
+		ret = process(tool, ff.buf, NULL, NULL);
+		if (ret) {
+			free(ff.buf);
+			return ret;
+		}
+	}
+	free(ff.buf);
+	return 0;
+}
+
+int perf_event__process_feature(struct perf_tool *tool,
+				union perf_event *event,
+				struct perf_session *session __maybe_unused)
+{
+	struct feat_fd ff = { .fd = 0 };
+	struct feature_event *fe = (struct feature_event *)event;
+	int type = fe->header.type;
+	u64 feat = fe->feat_id;
+
+	if (type < 0 || type >= PERF_RECORD_HEADER_MAX) {
+		pr_warning("invalid record type %d in pipe-mode\n", type);
+		return 0;
+	}
+	if (feat == HEADER_RESERVED || feat > HEADER_LAST_FEATURE) {
+		pr_warning("invalid record type %d in pipe-mode\n", type);
+		return -1;
+	}
+
+	if (!feat_ops[feat].process)
+		return 0;
+
+	ff.buf  = (void *)fe->data;
+	ff.size = event->header.size - sizeof(event->header);
+	ff.ph = &session->header;
+
+	if (feat_ops[feat].process(&ff, NULL))
+		return -1;
+
+	if (!feat_ops[feat].print || !tool->show_feat_hdr)
+		return 0;
+
+	if (!feat_ops[feat].full_only ||
+	    tool->show_feat_hdr >= SHOW_FEAT_HEADER_FULL_INFO) {
+		feat_ops[feat].print(&ff, stdout);
+	} else {
+		fprintf(stdout, "# %s info available, use -I to display\n",
+			feat_ops[feat].name);
+	}
+
+	return 0;
+}
+
 static struct event_update_event *
 event_update_event__new(size_t size, u64 type, u64 id)
 {