qmp: generalize watchdog-set-action to -no-reboot/-no-shutdown

Add a QMP command to allow for the behaviors specified by the
-no-reboot and -no-shutdown command line option to be set at runtime.
The new command is named set-action and takes optional arguments, named
after an event, that provide a corresponding action to take.

Example:

-> { "execute": "set-action",
     "arguments": {
	"reboot": "none",
	"shutdown": "poweroff",
	"watchdog": "debug" } }
<- { "return": {} }

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Message-Id: <1607705564-26264-4-git-send-email-alejandro.j.jimenez@oracle.com>
[Split the series differently, with -action based on the QMP command. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

MAINTAINERS

@@ -2357,6 +2357,7 @@ M: Paolo Bonzini <pbonzini@redhat.com>
 S: Maintained
 F: include/qemu/main-loop.h
 F: include/sysemu/runstate.h
+F: include/sysemu/runstate-action.h
 F: util/main-loop.c
 F: util/qemu-timer.c
 F: softmmu/vl.c
@@ -2365,6 +2366,7 @@ F: softmmu/cpus.c
 F: softmmu/cpu-throttle.c
 F: softmmu/cpu-timers.c
 F: softmmu/icount.c
+F: softmmu/runstate-action.c
 F: qapi/run-state.json
 
 Read, Copy, Update (RCU)

include/sysemu/runstate-action.h

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef RUNSTATE_ACTION_H
+#define RUNSTATE_ACTION_H
+
+#include "qapi/qapi-commands-run-state.h"
+
+/* in softmmu/runstate-action.c */
+extern RebootAction reboot_action;
+extern ShutdownAction shutdown_action;
+
+#endif /* RUNSTATE_ACTION_H */

include/sysemu/sysemu.h

@@ -43,8 +43,6 @@ extern int win2k_install_hack;
 extern int alt_grab;
 extern int ctrl_grab;
 extern int graphic_rotate;
-extern int no_shutdown;
-extern int no_reboot;
 extern int old_param;
 extern int boot_menu;
 extern bool boot_strict;

monitor/qmp-cmds.c

@@ -26,6 +26,7 @@
 #include "ui/vnc.h"
 #include "sysemu/kvm.h"
 #include "sysemu/runstate.h"
+#include "sysemu/runstate-action.h"
 #include "sysemu/arch_init.h"
 #include "sysemu/blockdev.h"
 #include "sysemu/block-backend.h"
@@ -72,7 +73,7 @@ UuidInfo *qmp_query_uuid(Error **errp)
 
 void qmp_quit(Error **errp)
 {
-    no_shutdown = 0;
+    shutdown_action = SHUTDOWN_ACTION_POWEROFF;
     qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_QMP_QUIT);
 }
 

qapi/run-state.json

@@ -325,6 +325,34 @@
   'data': [ 'reset', 'shutdown', 'poweroff', 'pause', 'debug', 'none',
             'inject-nmi' ] }
 
+##
+# @RebootAction:
+#
+# Possible QEMU actions upon guest reboot
+#
+# @none: Reset the VM
+#
+# @shutdown: Shutdown the VM and exit
+#
+# Since: 6.0
+##
+{ 'enum': 'RebootAction',
+  'data': [ 'none', 'shutdown' ] }
+
+##
+# @ShutdownAction:
+#
+# Possible QEMU actions upon guest shutdown
+#
+# @poweroff: Shutdown the VM and exit
+#
+# @pause: pause the VM#
+#
+# Since: 6.0
+##
+{ 'enum': 'ShutdownAction',
+  'data': [ 'poweroff', 'pause' ] }
+
 ##
 # @watchdog-set-action:
 #
@@ -334,6 +362,36 @@
 ##
 { 'command': 'watchdog-set-action', 'data' : {'action': 'WatchdogAction'} }
 
+##
+# @set-action:
+#
+# Set the actions that will be taken by the emulator in response to guest
+# events.
+#
+# @reboot: @RebootAction action taken on guest reboot.
+#
+# @shutdown: @ShutdownAction action taken on guest shutdown.
+#
+# @watchdog: @WatchdogAction action taken when watchdog timer expires .
+#
+# Returns: Nothing on success.
+#
+# Since: 6.0
+#
+# Example:
+#
+# -> { "execute": "set-action",
+#      "arguments": { "reboot": "shutdown",
+#                     "shutdown" : "pause",
+#                     "watchdog": "inject-nmi" } }
+# <- { "return": {} }
+##
+{ 'command': 'set-action',
+  'data': { '*reboot': 'RebootAction',
+            '*shutdown': 'ShutdownAction',
+            '*watchdog': 'WatchdogAction' },
+  'allow-preconfig': true }
+
 ##
 # @GUEST_PANICKED:
 #

softmmu/globals.c

@@ -46,8 +46,6 @@ Chardev *parallel_hds[MAX_PARALLEL_PORTS];
 int win2k_install_hack;
 int singlestep;
 int fd_bootchk = 1;
-int no_reboot;
-int no_shutdown;
 int graphic_rotate;
 QEMUOptionRom option_rom[MAX_OPTION_ROMS];
 int nb_option_roms;

softmmu/meson.build

@@ -14,6 +14,7 @@ specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: [files(
   'qtest.c',
   'vl.c',
   'cpu-timers.c',
+  'runstate-action.c',
 )])
 
 specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: [files(

softmmu/runstate-action.c

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "sysemu/runstate-action.h"
+#include "sysemu/watchdog.h"
+#include "qemu/config-file.h"
+#include "qapi/error.h"
+#include "qemu/option_int.h"
+
+RebootAction reboot_action = REBOOT_ACTION_NONE;
+ShutdownAction shutdown_action = SHUTDOWN_ACTION_POWEROFF;
+
+/*
+ * Receives actions to be applied for specific guest events
+ * and sets the internal state as requested.
+ */
+void qmp_set_action(bool has_reboot, RebootAction reboot,
+                    bool has_shutdown, ShutdownAction shutdown,
+                    bool has_panic, PanicAction panic,
+                    bool has_watchdog, WatchdogAction watchdog,
+                    Error **errp)
+{
+    if (has_reboot) {
+        reboot_action = reboot;
+    }
+
+    if (has_watchdog) {
+        qmp_watchdog_set_action(watchdog, errp);
+    }
+
+    /* Process shutdown last, in case the panic action needs to be altered */
+    if (has_shutdown) {
+        shutdown_action = shutdown;
+    }
+}

softmmu/runstate.c

@@ -54,6 +54,7 @@
 #include "sysemu/replay.h"
 #include "sysemu/reset.h"
 #include "sysemu/runstate.h"
+#include "sysemu/runstate-action.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/tpm.h"
 #include "trace.h"
@@ -471,7 +472,7 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
     qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE,
                                    !!info, info);
     vm_stop(RUN_STATE_GUEST_PANICKED);
-    if (!no_shutdown) {
+    if (shutdown_action == SHUTDOWN_ACTION_POWEROFF) {
         qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_POWEROFF,
                                        !!info, info);
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_PANIC);
@@ -512,7 +513,8 @@ void qemu_system_guest_crashloaded(GuestPanicInformation *info)
 
 void qemu_system_reset_request(ShutdownCause reason)
 {
-    if (no_reboot && reason != SHUTDOWN_CAUSE_SUBSYSTEM_RESET) {
+    if (reboot_action == REBOOT_ACTION_SHUTDOWN &&
+        reason != SHUTDOWN_CAUSE_SUBSYSTEM_RESET) {
         shutdown_requested = reason;
     } else {
         reset_requested = reason;
@@ -591,7 +593,7 @@ void qemu_system_killed(int signal, pid_t pid)
 {
     shutdown_signal = signal;
     shutdown_pid = pid;
-    no_shutdown = 0;
+    shutdown_action = SHUTDOWN_ACTION_POWEROFF;
 
     /* Cannot call qemu_system_shutdown_request directly because
      * we are in a signal handler.
@@ -658,7 +660,7 @@ static bool main_loop_should_exit(void)
     if (request) {
         qemu_kill_report();
         qemu_system_shutdown(request);
-        if (no_shutdown) {
+        if (shutdown_action == SHUTDOWN_ACTION_PAUSE) {
             vm_stop(RUN_STATE_SHUTDOWN);
         } else {
             return true;

softmmu/vl.c

@@ -36,6 +36,7 @@
 #include "qemu/uuid.h"
 #include "sysemu/reset.h"
 #include "sysemu/runstate.h"
+#include "sysemu/runstate-action.h"
 #include "sysemu/seccomp.h"
 #include "sysemu/tcg.h"
 #include "sysemu/xen.h"
@@ -3154,10 +3155,10 @@ void qemu_init(int argc, char **argv, char **envp)
                 qemu_opts_parse_noisily(olist, "hpet=off", false);
                 break;
             case QEMU_OPTION_no_reboot:
-                no_reboot = 1;
+                reboot_action = REBOOT_ACTION_SHUTDOWN;
                 break;
             case QEMU_OPTION_no_shutdown:
-                no_shutdown = 1;
+                shutdown_action = SHUTDOWN_ACTION_PAUSE;
                 break;
             case QEMU_OPTION_show_cursor:
                 warn_report("The -show-cursor option is deprecated. Please "

ui/sdl2.c

@@ -30,6 +30,7 @@
 #include "ui/input.h"
 #include "ui/sdl2.h"
 #include "sysemu/runstate.h"
+#include "sysemu/runstate-action.h"
 #include "sysemu/sysemu.h"
 #include "ui/win32-kbd-hook.h"
 
@@ -606,7 +607,7 @@ static void handle_windowevent(SDL_Event *ev)
                 allow_close = false;
             }
             if (allow_close) {
-                no_shutdown = 0;
+                shutdown_action = SHUTDOWN_ACTION_POWEROFF;
                 qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_UI);
             }
         } else {
@@ -653,7 +654,7 @@ void sdl2_poll_events(struct sdl2_console *scon)
                 allow_close = false;
             }
             if (allow_close) {
-                no_shutdown = 0;
+                shutdown_action = SHUTDOWN_ACTION_POWEROFF;
                 qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_UI);
             }
             break;