trap signals for "-serial mon:stdio"

With mon:stdio you can exit the VM by switching to the monitor and
sending the "quit" command.  It is then useful to pass Ctrl-C to the
VM instead of exiting.

This in turn lets us stop tying the default signal handling behavior
to -nographic, removing gratuitous differences between "-display none"
and "-nographic".

This patch changes behavior for "-display none -serial mon:stdio", as
expected, but not for "-display none -serial stdio".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1372868986-25988-1-git-send-email-mjt@msgid.tls.msk.ru
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Paolo Bonzini 2013-07-03 20:29:45 +04:00 committed by Anthony Liguori
parent 964c6fa16f
commit 02c4bdf1d2
2 changed files with 14 additions and 7 deletions

View File

@ -926,7 +926,6 @@ static void qemu_chr_set_echo_stdio(CharDriverState *chr, bool echo)
tty.c_cc[VMIN] = 1;
tty.c_cc[VTIME] = 0;
}
/* if graphical mode, we allow Ctrl-C handling */
if (!stdio_allow_signal)
tty.c_lflag &= ~ISIG;
@ -955,7 +954,6 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
chr = qemu_chr_open_fd(0, 1);
chr->chr_close = qemu_chr_close_stdio;
chr->chr_set_echo = qemu_chr_set_echo_stdio;
stdio_allow_signal = display_type != DT_NOGRAPHIC;
if (opts->has_signal) {
stdio_allow_signal = opts->signal;
}
@ -2932,6 +2930,14 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
if (strstart(filename, "mon:", &p)) {
filename = p;
qemu_opt_set(opts, "mux", "on");
if (strcmp(filename, "stdio") == 0) {
/* Monitor is muxed to stdio: do not exit on Ctrl+C by default
* but pass it to the guest. Handle this only for compat syntax,
* for -chardev syntax we have special option for this.
* This is what -nographic did, redirecting+muxing serial+monitor
* to stdio causing Ctrl+C to be passed to guest. */
qemu_opt_set(opts, "signal", "off");
}
}
if (strcmp(filename, "null") == 0 ||
@ -3060,8 +3066,7 @@ static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
{
backend->stdio = g_new0(ChardevStdio, 1);
backend->stdio->has_signal = true;
backend->stdio->signal =
qemu_opt_get_bool(opts, "signal", display_type != DT_NOGRAPHIC);
backend->stdio->signal = qemu_opt_get_bool(opts, "signal", true);
}
static void qemu_chr_parse_serial(QemuOpts *opts, ChardevBackend *backend,

View File

@ -842,7 +842,8 @@ STEXI
Normally, QEMU uses SDL to display the VGA output. With this option,
you can totally disable graphical output so that QEMU is a simple
command line application. The emulated serial port is redirected on
the console. Therefore, you can still use QEMU to debug a Linux kernel
the console and muxed with the monitor (unless redirected elsewhere
explicitly). Therefore, you can still use QEMU to debug a Linux kernel
with a serial console.
ETEXI
@ -2485,14 +2486,15 @@ same as if you had specified @code{-serial tcp} except the unix domain socket
@item mon:@var{dev_string}
This is a special option to allow the monitor to be multiplexed onto
another serial port. The monitor is accessed with key sequence of
@key{Control-a} and then pressing @key{c}. See monitor access
@ref{pcsys_keys} in the -nographic section for more keys.
@key{Control-a} and then pressing @key{c}.
@var{dev_string} should be any one of the serial devices specified
above. An example to multiplex the monitor onto a telnet server
listening on port 4444 would be:
@table @code
@item -serial mon:telnet::4444,server,nowait
@end table
When monitor is multiplexed to stdio this way, Ctrl+C will not terminate
QEMU anymore but will be passed to the guest instead.
@item braille
Braille device. This will use BrlAPI to display the braille output on a real