[PATCH 15/20] perf kvm: Fix stdin handling for 'kvm stat live' command

[Jiri Olsa <jolsa@kernel.org>]

Currently the initial ~(ICANON | ECHO) terminal mode is
not set, so we dont get stdin data until we press ENTER.

Fixing this by early setting of the ~(ICANON | ECHO) mode
and leaving this mode for whole life of the command, because
canonical mode is not needed.

This fix is preparation for the poller object installation
into 'kvm stat live' command.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-kvm.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 7ccceadcd9f8..ff404750d744 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -885,15 +885,11 @@ static int fd_set_nonblock(int fd)
 	return 0;
 }
 
-static
-int perf_kvm__handle_stdin(struct termios *tc_now, struct termios *tc_save)
+static int perf_kvm__handle_stdin(void)
 {
 	int c;
 
-	tcsetattr(0, TCSANOW, tc_now);
 	c = getc(stdin);
-	tcsetattr(0, TCSAFLUSH, tc_save);
-
 	if (c == 'q')
 		return 1;
 
@@ -904,7 +900,7 @@ static int kvm_events_live_report(struct perf_kvm_stat *kvm)
 {
 	struct pollfd *pollfds = NULL;
 	int nr_fds, nr_stdin, ret, err = -EINVAL;
-	struct termios tc, save;
+	struct termios save;
 
 	/* live flag must be set first */
 	kvm->live = true;
@@ -919,14 +915,9 @@ static int kvm_events_live_report(struct perf_kvm_stat *kvm)
 		goto out;
 	}
 
+	set_term_quiet_input(&save);
 	init_kvm_event_record(kvm);
 
-	tcgetattr(0, &save);
-	tc = save;
-	tc.c_lflag &= ~(ICANON | ECHO);
-	tc.c_cc[VMIN] = 0;
-	tc.c_cc[VTIME] = 0;
-
 	signal(SIGINT, sig_handler);
 	signal(SIGTERM, sig_handler);
 
@@ -972,7 +963,7 @@ static int kvm_events_live_report(struct perf_kvm_stat *kvm)
 			goto out;
 
 		if (pollfds[nr_stdin].revents & POLLIN)
-			done = perf_kvm__handle_stdin(&tc, &save);
+			done = perf_kvm__handle_stdin();
 
 		if (!rc && !done)
 			err = poll(pollfds, nr_fds, 100);
@@ -989,6 +980,7 @@ out:
 	if (kvm->timerfd >= 0)
 		close(kvm->timerfd);
 
+	tcsetattr(0, TCSAFLUSH, &save);
 	free(pollfds);
 	return err;
 }
-- 
1.8.3.1