perf kvm: Add TUI mode for stat report

Since we have supported histograms list and prepared the dimensions in
the tool, this patch adds TUI mode for stat report. It also adds UI
progress for sorting for better user experience.

Committer notes:

kvm_display() is only used by functions enclosed in:

#if defined(HAVE_KVM_STAT_SUPPORT) && defined(HAVE_LIBTRACEEVENT)

So do it with this new function as well.

Signed-off-by: Leo Yan <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-kvm.c

···
 #include "util/data.h"
 #include "util/ordered-events.h"
 #include "util/kvm-stat.h"
+#include "ui/browsers/hists.h"
+#include "ui/progress.h"
 #include "ui/ui.h"
 #include "util/string2.h"
 
···
 
 static int kvm_hists__init(void)
 {
+	kvm_hists.list.nr_header_lines = 1;
 	__hists__init(&kvm_hists.hists, &kvm_hists.list);
 	perf_hpp_list__init(&kvm_hists.list);
 	return kvm_hpp_list__parse(&kvm_hists.list, NULL, "ev_name");
···
 	perf_hpp__reset_output_field(&kvm_hists.list);
 	return kvm_hpp_list__parse(&kvm_hists.list, output, sort);
 }
+static void print_result(struct perf_kvm_stat *kvm);
+
+#ifdef HAVE_SLANG_SUPPORT
+static void kvm_browser__update_nr_entries(struct hist_browser *hb)
+{
+	struct rb_node *nd = rb_first_cached(&hb->hists->entries);
+	u64 nr_entries = 0;
+
+	for (; nd; nd = rb_next(nd)) {
+		struct hist_entry *he = rb_entry(nd, struct hist_entry,
+						 rb_node);
+
+		if (!he->filtered)
+			nr_entries++;
+	}
+
+	hb->nr_non_filtered_entries = nr_entries;
+}
+
+static int kvm_browser__title(struct hist_browser *browser,
+			      char *buf, size_t size)
+{
+	scnprintf(buf, size, "KVM event statistics (%lu entries)",
+		  browser->nr_non_filtered_entries);
+	return 0;
+}
+
+static struct hist_browser*
+perf_kvm_browser__new(struct hists *hists)
+{
+	struct hist_browser *browser = hist_browser__new(hists);
+
+	if (browser)
+		browser->title = kvm_browser__title;
+
+	return browser;
+}
+
+static int kvm__hists_browse(struct hists *hists)
+{
+	struct hist_browser *browser;
+	int key = -1;
+
+	browser = perf_kvm_browser__new(hists);
+	if (browser == NULL)
+		return -1;
+
+	/* reset abort key so that it can get Ctrl-C as a key */
+	SLang_reset_tty();
+	SLang_init_tty(0, 0, 0);
+
+	kvm_browser__update_nr_entries(browser);
+
+	while (1) {
+		key = hist_browser__run(browser, "? - help", true, 0);
+
+		switch (key) {
+		case 'q':
+			goto out;
+		default:
+			break;
+		}
+	}
+
+out:
+	hist_browser__delete(browser);
+	return 0;
+}
+
+static void kvm_display(struct perf_kvm_stat *kvm)
+{
+	if (!use_browser)
+		print_result(kvm);
+	else
+		kvm__hists_browse(&kvm_hists.hists);
+}
+
+#else
+
+static void kvm_display(struct perf_kvm_stat *kvm)
+{
+	use_browser = 0;
+	print_result(kvm);
+}
+
+#endif /* HAVE_SLANG_SUPPORT */
+
 #endif // defined(HAVE_KVM_STAT_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
 
 static const char *get_filename_for_perf_kvm(void)
···
 
 static void sort_result(struct perf_kvm_stat *kvm)
 {
+	struct ui_progress prog;
 	const char *output_columns = "ev_name,sample,percent_sample,"
 				     "time,percent_time,max_t,min_t,mean_t";
 
 	kvm_hists__reinit(output_columns, kvm->sort_key);
+	ui_progress__init(&prog, kvm_hists.hists.nr_entries, "Sorting...");
 	hists__collapse_resort(&kvm_hists.hists, NULL);
 	hists__output_resort_cb(&kvm_hists.hists, NULL, filter_cb);
+	ui_progress__finish();
 }
 
 static void print_vcpu_info(struct perf_kvm_stat *kvm)
···
 	if (!register_kvm_events_ops(kvm))
 		goto exit;
 
-	setup_pager();
+	if (kvm->use_stdio) {
+		use_browser = 0;
+		setup_pager();
+	} else {
+		use_browser = 1;
+	}
+
+	setup_browser(false);
 
 	kvm_hists__init();
 
···
 		goto exit;
 
 	sort_result(kvm);
-	print_result(kvm);
+	kvm_display(kvm);
 
 exit:
 	return ret;
···
 		OPT_STRING('p', "pid", &kvm->opts.target.pid, "pid",
 			   "analyze events only for given process id(s)"),
 		OPT_BOOLEAN('f', "force", &kvm->force, "don't complain, do it"),
+		OPT_BOOLEAN(0, "stdio", &kvm->use_stdio, "use the stdio interface"),
 		OPT_END()
 	};
 
···
 			usage_with_options(kvm_events_report_usage,
 					   kvm_events_report_options);
 	}
+
+#ifndef HAVE_SLANG_SUPPORT
+	kvm->use_stdio = true;
+#endif
 
 	if (!kvm->opts.target.pid)
 		kvm->opts.target.system_wide = true;

tools/perf/util/kvm-stat.h

···
 	unsigned int display_time;
 	bool live;
 	bool force;
+	bool use_stdio;
 };
 
 struct kvm_reg_events_ops {