Commit 02c4bdf1 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Anthony Liguori
Browse files

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: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarMichael Tokarev <mjt@tls.msk.ru>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 1372868986-25988-1-git-send-email-mjt@msgid.tls.msk.ru
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 964c6fa1

qemu-char.c

+9 −4
Original line number Diff line number Diff line
@@ -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,

qemu-options.hx

+5 −3
Original line number Diff line number Diff line
@@ -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