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* [PATCH v3 0/4] Add a new -action parameter
@ 2020-12-11 16:52 Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 1/4] vl: Add an -action option to respond to guest events Alejandro Jimenez
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Alejandro Jimenez @ 2020-12-11 16:52 UTC (permalink / raw)
  To: qemu-devel; +Cc: david.edmondson, pbonzini, mihai.carabas

v3:
- Replaced the no_reboot and no_shutdown internal flags with enumerations that hold the current action
selected in case of reboot or shutdown events. The same approach is used for panic and watchdog events.
- Ensured that -no-shutdown option overrides any previously issued action panic=poweroff setting.
- Added TODO comment to add more panic actions if viable (debug, reset).
- Modified QMP command to take multiple optional args specifying actions for each event type,
and added 'allow-preconfig': true

v2:
- Replaced the individual qmp commands in patch 3/4 for a generic set-action
command that takes a RunStateAction parameter, specifying an event|action pair.
- Removed qmp_ prefix from X_set_action() functions in runstate-action.c

***

This is a follow up to the proposal to add a "-no-panicstop" option to QEMU that would allow us to
control whether the VM is paused or allowed to continue running without intervention from a management layer
when a guest panic occurs. See the inital thread and replies for details:

https://lore.kernel.org/qemu-devel/1601606494-1154-1-git-send-email-alejandro.j.jimenez@oracle.com/

From that discussion came a request for a generic mechanism to group options like -no-shutdown, -no-reboot, etc,
that specify an action taken by QEMU in response to a guest event (reboot, shutdown, panic, and watchdog
expiration are the current options). The existing options would translate to the new option, like:

* -no-reboot --> "-action reboot=shutdown"
* -no-shutdown --> "-action shutdown=pause"

Please share any questions or comments.

Regards,
Alejandro

Alejandro Jimenez (4):
  vl: Add an -action option to respond to guest events
  vl: Add option to avoid stopping VM upon guest panic
  qmp: Allow setting -action parameters on the fly
  qtest/pvpanic: Test panic option that allows VM to continue

 MAINTAINERS                      |   2 +
 include/sysemu/runstate-action.h |  22 ++++++
 include/sysemu/sysemu.h          |   1 -
 monitor/qmp-cmds.c               |   3 +-
 qapi/run-state.json              | 149 +++++++++++++++++++++++++++++++++++++++
 qemu-options.hx                  |  25 +++++++
 softmmu/meson.build              |   1 +
 softmmu/runstate-action.c        | 142 +++++++++++++++++++++++++++++++++++++
 softmmu/vl.c                     |  64 ++++++++++++++---
 tests/qtest/pvpanic-test.c       |  26 ++++++-
 ui/sdl2.c                        |   5 +-
 11 files changed, 424 insertions(+), 16 deletions(-)
 create mode 100644 include/sysemu/runstate-action.h
 create mode 100644 softmmu/runstate-action.c

-- 
1.8.3.1



^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v3 1/4] vl: Add an -action option to respond to guest events
  2020-12-11 16:52 [PATCH v3 0/4] Add a new -action parameter Alejandro Jimenez
@ 2020-12-11 16:52 ` Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 2/4] vl: Add option to avoid stopping VM upon guest panic Alejandro Jimenez
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Alejandro Jimenez @ 2020-12-11 16:52 UTC (permalink / raw)
  To: qemu-devel; +Cc: david.edmondson, pbonzini, mihai.carabas

Several command line options currently in use are meant to modify
the behavior of QEMU in response to certain guest events like:
-no-reboot, -no-shutdown, -watchdog-action.

These can be grouped into a single option of the form:

-action event=action

Which can be used to specify the existing options above in the
following format:

-action reboot=none|shutdown
-action shutdown=poweroff|pause
-action watchdog=reset|shutdown|poweroff|pause|debug|none|inject-nmi

This is done in preparation for adding yet another option of this
type, which modifies the QEMU behavior when a guest panic occurs.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
 MAINTAINERS                      |  2 +
 include/sysemu/runstate-action.h | 21 +++++++++
 include/sysemu/sysemu.h          |  1 -
 monitor/qmp-cmds.c               |  3 +-
 qapi/run-state.json              | 90 +++++++++++++++++++++++++++++++++++++
 qemu-options.hx                  | 22 +++++++++
 softmmu/meson.build              |  1 +
 softmmu/runstate-action.c        | 96 ++++++++++++++++++++++++++++++++++++++++
 softmmu/vl.c                     | 43 ++++++++++++++----
 ui/sdl2.c                        |  5 ++-
 10 files changed, 272 insertions(+), 12 deletions(-)
 create mode 100644 include/sysemu/runstate-action.h
 create mode 100644 softmmu/runstate-action.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 68bc160..7dcc4bd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2332,6 +2332,7 @@ 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
@@ -2340,6 +2341,7 @@ 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)
diff --git a/include/sysemu/runstate-action.h b/include/sysemu/runstate-action.h
new file mode 100644
index 0000000..dba4b85
--- /dev/null
+++ b/include/sysemu/runstate-action.h
@@ -0,0 +1,21 @@
+/*
+ * 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;
+
+int process_runstate_actions(void *opaque, QemuOpts *opts, Error **errp);
+int runstate_action_parse(QemuOptsList *opts_list, const char *optarg);
+
+#endif /* RUNSTATE_ACTION_H */
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 817ff4c..dd6897f 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -43,7 +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 old_param;
 extern int boot_menu;
 extern bool boot_strict;
diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
index a08143b..3589550 100644
--- a/monitor/qmp-cmds.c
+++ b/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);
 }
 
diff --git a/qapi/run-state.json b/qapi/run-state.json
index 964c8ef..7d8ce61 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -329,6 +329,96 @@
             'inject-nmi' ] }
 
 ##
+# @RunStateEventType:
+#
+# An enumeration of Run State event types
+#
+# @reboot: Guest reboot
+#
+# @shutdown: Guest shutdown
+#
+# @watchdog: A watchdog device's timer has expired
+#
+# Since: 6.0
+##
+{ 'enum': 'RunStateEventType',
+  'data': [ 'reboot', 'shutdown', 'watchdog' ] }
+
+##
+# @RunStateAction:
+#
+# Describes a guest event and the subsequent action that is taken
+# by QEMU when such event takes place.
+#
+# Since: 6.0
+##
+{ 'union': 'RunStateAction',
+  'base': { 'event': 'RunStateEventType' },
+  'discriminator': 'event',
+  'data': {
+    'reboot': 'RunStateRebootAction',
+    'shutdown': 'RunStateShutdownAction',
+    'watchdog': 'RunStateWatchdogAction' } }
+
+##
+# @RunStateRebootAction:
+#
+# @action: Action taken by QEMU when guest reboots
+#
+# Since: 6.0
+##
+{ 'struct': 'RunStateRebootAction',
+  'data': { 'action': 'RebootAction' } }
+
+##
+# @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' ] }
+
+##
+# @RunStateShutdownAction:
+#
+# @action: Action taken by QEMU when guest shuts down
+#
+# Since: 6.0
+##
+{ 'struct': 'RunStateShutdownAction',
+  'data': { 'action': 'ShutdownAction' } }
+
+##
+# @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' ] }
+
+##
+# @RunStateWatchdogAction:
+#
+# @action: Action taken by QEMU when watchdog device timer expires
+#
+# Since: 6.0
+##
+{ 'struct': 'RunStateWatchdogAction',
+  'data': { 'action': 'WatchdogAction' } }
+
+##
 # @watchdog-set-action:
 #
 # Set watchdog action
diff --git a/qemu-options.hx b/qemu-options.hx
index 104632e..a0d50f0 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3894,6 +3894,28 @@ SRST
     changes to the disk image.
 ERST
 
+DEF("action", HAS_ARG, QEMU_OPTION_action,
+    "-action reboot=none|shutdown\n"
+    "                   action when guest reboots [default=none]\n"
+    "-action shutdown=poweroff|pause\n"
+    "                   action when guest shuts down [default=poweroff]\n"
+    "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
+    "                   action when watchdog fires [default=reset]\n",
+    QEMU_ARCH_ALL)
+SRST
+``-action event=action``
+    The action parameter serves to modify QEMU's default behavior when
+    certain guest events occur. It provides a generic method for specifying the
+    same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown``
+    parameters.
+
+    Examples:
+
+    ``-action reboot=shutdown,shutdown=pause``
+    ``-watchdog i6300esb -action watchdog=pause``
+
+ERST
+
 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
     "-loadvm [tag|id]\n" \
     "                start right away with a saved state (loadvm in monitor)\n",
diff --git a/softmmu/meson.build b/softmmu/meson.build
index 8f7210b..8ad586e 100644
--- a/softmmu/meson.build
+++ b/softmmu/meson.build
@@ -10,6 +10,7 @@ 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(
diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
new file mode 100644
index 0000000..5eae320
--- /dev/null
+++ b/softmmu/runstate-action.c
@@ -0,0 +1,96 @@
+/*
+ * 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;
+
+static void runstate_action_help(void)
+{
+    int idx;
+
+    printf("Events for which an action can be specified:\n");
+    for (idx = 0; idx < RUN_STATE_EVENT_TYPE__MAX; idx++) {
+        printf("%10s\n", RunStateEventType_str(idx));
+    }
+}
+
+/*
+ * Process an event|action pair and set the appropriate internal
+ * state if event and action are valid.
+ */
+static int set_runstate_action(void *opaque, const char *event,
+                                const char *action, Error **errp)
+{
+    int event_idx;
+
+    event_idx = qapi_enum_parse(&RunStateEventType_lookup, event, -1, errp);
+
+    switch (event_idx) {
+    case RUN_STATE_EVENT_TYPE_REBOOT:
+        reboot_action = qapi_enum_parse(&RebootAction_lookup,
+                                            action, -1, errp);
+        break;
+    case RUN_STATE_EVENT_TYPE_SHUTDOWN:
+        shutdown_action = qapi_enum_parse(&ShutdownAction_lookup,
+                                            action, -1, errp);
+        break;
+    case RUN_STATE_EVENT_TYPE_WATCHDOG:
+        if (select_watchdog_action(action) == -1) {
+            error_report("invalid parameter value: %s", action);
+            exit(1);
+        }
+        break;
+    default:
+        /*
+         * The event and action types are checked for validity in the calls to
+         * qapi_enum_parse(), which will cause an exit if the requested event or
+         * action are invalid, since error_fatal is used as the error parameter.
+         * This case is unreachable unless those conditions change.
+         */
+        g_assert_not_reached();
+    }
+
+    return 0;
+}
+
+/*
+ * Parse provided -action arguments from cmdline.
+ */
+int runstate_action_parse(QemuOptsList *opts_list, const char *optarg)
+{
+    QemuOpts *opts;
+
+    if (!strcmp(optarg, "help")) {
+        runstate_action_help();
+        return -1;
+    }
+
+    opts = qemu_opts_parse_noisily(opts_list, optarg, false);
+    if (!opts) {
+        return -1;
+    }
+    return 0;
+}
+
+/*
+ * Process all the -action parameters parsed from cmdline.
+ */
+int process_runstate_actions(void *opaque, QemuOpts *opts, Error **errp)
+{
+    if (qemu_opt_foreach(opts, set_runstate_action, NULL, errp)) {
+        return -1;
+    }
+    return 0;
+}
diff --git a/softmmu/vl.c b/softmmu/vl.c
index e6e0ad5..35575a1 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -34,6 +34,7 @@
 #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"
@@ -147,8 +148,6 @@ Chardev *parallel_hds[MAX_PARALLEL_PORTS];
 int win2k_install_hack = 0;
 int singlestep = 0;
 int fd_bootchk = 1;
-static int no_reboot;
-int no_shutdown = 0;
 int graphic_rotate = 0;
 const char *watchdog;
 QEMUOptionRom option_rom[MAX_OPTION_ROMS];
@@ -506,6 +505,21 @@ static QemuOptsList qemu_fw_cfg_opts = {
     },
 };
 
+static QemuOptsList qemu_action_opts = {
+    .name = "action",
+    /*
+     * When lists are merged, the location is set to the first use of the
+     * option. If a subsequent option has an invalid parameter, the error msg
+     * will display the wrong location. Avoid this by not merging the lists.
+     */
+    .merge_lists = false,
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_action_opts.head),
+    .desc = {
+        /* Validation is done when processing the runstate actions */
+        { }
+    },
+};
+
 /**
  * Get machine options
  *
@@ -1436,7 +1450,7 @@ 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);
@@ -1477,7 +1491,8 @@ 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;
@@ -1554,7 +1569,7 @@ 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.
@@ -1628,7 +1643,7 @@ 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;
@@ -2948,6 +2963,7 @@ void qemu_init(int argc, char **argv, char **envp)
     qemu_add_opts(&qemu_icount_opts);
     qemu_add_opts(&qemu_semihosting_config_opts);
     qemu_add_opts(&qemu_fw_cfg_opts);
+    qemu_add_opts(&qemu_action_opts);
     module_call_init(MODULE_INIT_OPTS);
 
     runstate_init();
@@ -3420,6 +3436,12 @@ void qemu_init(int argc, char **argv, char **envp)
                 }
                 watchdog = optarg;
                 break;
+            case QEMU_OPTION_action:
+                if (runstate_action_parse(qemu_find_opts("action"),
+                                            optarg) < 0) {
+                    exit(1);
+                }
+                break;
             case QEMU_OPTION_watchdog_action:
                 if (select_watchdog_action(optarg) == -1) {
                     error_report("unknown -watchdog-action parameter");
@@ -3565,10 +3587,10 @@ 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 "
@@ -3902,6 +3924,11 @@ void qemu_init(int argc, char **argv, char **envp)
     qemu_opts_foreach(qemu_find_opts("name"),
                       parse_name, NULL, &error_fatal);
 
+    if (qemu_opts_foreach(qemu_find_opts("action"),
+                        process_runstate_actions, NULL, &error_fatal)) {
+        exit(1);
+    }
+
 #ifndef _WIN32
     qemu_opts_foreach(qemu_find_opts("add-fd"),
                       parse_add_fd, NULL, &error_fatal);
diff --git a/ui/sdl2.c b/ui/sdl2.c
index 189d26e..993c311 100644
--- a/ui/sdl2.c
+++ b/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"
 
@@ -604,7 +605,7 @@ 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 {
@@ -651,7 +652,7 @@ 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;
-- 
1.8.3.1



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 2/4] vl: Add option to avoid stopping VM upon guest panic
  2020-12-11 16:52 [PATCH v3 0/4] Add a new -action parameter Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 1/4] vl: Add an -action option to respond to guest events Alejandro Jimenez
@ 2020-12-11 16:52 ` Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 3/4] qmp: Allow setting -action parameters on the fly Alejandro Jimenez
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Alejandro Jimenez @ 2020-12-11 16:52 UTC (permalink / raw)
  To: qemu-devel; +Cc: david.edmondson, pbonzini, mihai.carabas

The current default action of pausing a guest after a panic event
is received leaves the responsibility to resume guest execution to the
management layer. The reasons for this behavior are discussed here:
https://lore.kernel.org/qemu-devel/52148F88.5000509@redhat.com/

However, in instances like the case of older guests (Linux and
Windows) using a pvpanic device but missing support for the
PVPANIC_CRASHLOADED event, and Windows guests using the hv-crash
enlightenment, it is desirable to allow the guests to continue
running after sending a PVPANIC_PANICKED event. This allows such
guests to proceed to capture a crash dump and automatically reboot
without intervention of a management layer.

Add an option to avoid stopping a VM after a panic event is received,
by passing:

-action panic=none

in the command line arguments, or during runtime by using an upcoming
QMP command.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
 include/sysemu/runstate-action.h |  1 +
 qapi/run-state.json              | 27 ++++++++++++++++++++++++++-
 qemu-options.hx                  |  3 +++
 softmmu/runstate-action.c        | 17 +++++++++++++++++
 softmmu/vl.c                     | 23 +++++++++++++++++++----
 5 files changed, 66 insertions(+), 5 deletions(-)

diff --git a/include/sysemu/runstate-action.h b/include/sysemu/runstate-action.h
index dba4b85..cfc46ec 100644
--- a/include/sysemu/runstate-action.h
+++ b/include/sysemu/runstate-action.h
@@ -14,6 +14,7 @@
 /* in softmmu/runstate-action.c */
 extern RebootAction reboot_action;
 extern ShutdownAction shutdown_action;
+extern PanicAction panic_action;
 
 int process_runstate_actions(void *opaque, QemuOpts *opts, Error **errp);
 int runstate_action_parse(QemuOptsList *opts_list, const char *optarg);
diff --git a/qapi/run-state.json b/qapi/run-state.json
index 7d8ce61..03ff78b 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -337,12 +337,14 @@
 #
 # @shutdown: Guest shutdown
 #
+# @panic: Guest has panicked
+#
 # @watchdog: A watchdog device's timer has expired
 #
 # Since: 6.0
 ##
 { 'enum': 'RunStateEventType',
-  'data': [ 'reboot', 'shutdown', 'watchdog' ] }
+  'data': [ 'reboot', 'shutdown', 'panic', 'watchdog' ] }
 
 ##
 # @RunStateAction:
@@ -358,6 +360,7 @@
   'data': {
     'reboot': 'RunStateRebootAction',
     'shutdown': 'RunStateShutdownAction',
+    'panic': 'RunStatePanicAction',
     'watchdog': 'RunStateWatchdogAction' } }
 
 ##
@@ -409,6 +412,28 @@
   'data': [ 'poweroff', 'pause' ] }
 
 ##
+# @RunStatePanicAction:
+#
+# @action: Action taken by QEMU when guest panicks
+#
+# Since: 6.0
+##
+{ 'struct': 'RunStatePanicAction',
+  'data': { 'action': 'PanicAction' } }
+
+##
+# @PanicAction:
+#
+# @none: Continue VM execution
+#
+# @pause: Pause the VM
+#
+# Since: 6.0
+##
+{ 'enum': 'PanicAction',
+  'data': [ 'poweroff', 'pause', 'none' ] }
+
+##
 # @RunStateWatchdogAction:
 #
 # @action: Action taken by QEMU when watchdog device timer expires
diff --git a/qemu-options.hx b/qemu-options.hx
index a0d50f0..9ac5a26 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3899,6 +3899,8 @@ DEF("action", HAS_ARG, QEMU_OPTION_action,
     "                   action when guest reboots [default=none]\n"
     "-action shutdown=poweroff|pause\n"
     "                   action when guest shuts down [default=poweroff]\n"
+    "-action panic=poweroff|pause|none\n"
+    "                   action when guest panics [default=poweroff]\n"
     "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
     "                   action when watchdog fires [default=reset]\n",
     QEMU_ARCH_ALL)
@@ -3911,6 +3913,7 @@ SRST
 
     Examples:
 
+    ``-action panic=none``
     ``-action reboot=shutdown,shutdown=pause``
     ``-watchdog i6300esb -action watchdog=pause``
 
diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
index 5eae320..bc30102 100644
--- a/softmmu/runstate-action.c
+++ b/softmmu/runstate-action.c
@@ -15,6 +15,7 @@
 
 RebootAction reboot_action = REBOOT_ACTION_NONE;
 ShutdownAction shutdown_action = SHUTDOWN_ACTION_POWEROFF;
+PanicAction panic_action = PANIC_ACTION_POWEROFF;
 
 static void runstate_action_help(void)
 {
@@ -27,6 +28,18 @@ static void runstate_action_help(void)
 }
 
 /*
+ * When -no-shutdown is requested either explicitly or by using its equivalent
+ * -action option, the request should be honored even if a panic occurs.
+ */
+static void fix_panic_action(void)
+{
+    if (shutdown_action == SHUTDOWN_ACTION_PAUSE &&
+                panic_action == PANIC_ACTION_POWEROFF) {
+        panic_action = PANIC_ACTION_PAUSE;
+    }
+}
+
+/*
  * Process an event|action pair and set the appropriate internal
  * state if event and action are valid.
  */
@@ -45,6 +58,10 @@ static int set_runstate_action(void *opaque, const char *event,
     case RUN_STATE_EVENT_TYPE_SHUTDOWN:
         shutdown_action = qapi_enum_parse(&ShutdownAction_lookup,
                                             action, -1, errp);
+        fix_panic_action();
+        break;
+    case RUN_STATE_EVENT_TYPE_PANIC:
+        panic_action = qapi_enum_parse(&PanicAction_lookup, action, -1, errp);
         break;
     case RUN_STATE_EVENT_TYPE_WATCHDOG:
         if (select_watchdog_action(action) == -1) {
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 35575a1..2ff0291 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1447,10 +1447,21 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
     if (current_cpu) {
         current_cpu->crash_occurred = true;
     }
-    qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE,
-                                   !!info, info);
-    vm_stop(RUN_STATE_GUEST_PANICKED);
-    if (shutdown_action == SHUTDOWN_ACTION_POWEROFF) {
+    /*
+     * TODO:  Currently the available panic actions are: none, pause, and
+     * poweroff, but in principle debug and reset could be supported as well.
+     * Investigate any potential use cases for the unimplemented actions.
+     */
+    if (panic_action != PANIC_ACTION_NONE) {
+        qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE,
+                                        !!info, info);
+        vm_stop(RUN_STATE_GUEST_PANICKED);
+    } else {
+        qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_RUN,
+                                        !!info, info);
+    }
+
+    if (panic_action == PANIC_ACTION_POWEROFF) {
         qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_POWEROFF,
                                        !!info, info);
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_PANIC);
@@ -3591,6 +3602,10 @@ void qemu_init(int argc, char **argv, char **envp)
                 break;
             case QEMU_OPTION_no_shutdown:
                 shutdown_action = SHUTDOWN_ACTION_PAUSE;
+                /* no_shutdown is requested, also honor it if guest panics */
+                if (panic_action == PANIC_ACTION_POWEROFF) {
+                    panic_action = PANIC_ACTION_PAUSE;
+                }
                 break;
             case QEMU_OPTION_show_cursor:
                 warn_report("The -show-cursor option is deprecated. Please "
-- 
1.8.3.1



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 3/4] qmp: Allow setting -action parameters on the fly
  2020-12-11 16:52 [PATCH v3 0/4] Add a new -action parameter Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 1/4] vl: Add an -action option to respond to guest events Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 2/4] vl: Add option to avoid stopping VM upon guest panic Alejandro Jimenez
@ 2020-12-11 16:52 ` Alejandro Jimenez
  2020-12-11 16:52 ` [PATCH v3 4/4] qtest/pvpanic: Test panic option that allows VM to continue Alejandro Jimenez
  2020-12-11 22:23 ` [PATCH v3 0/4] Add a new -action parameter Paolo Bonzini
  4 siblings, 0 replies; 6+ messages in thread
From: Alejandro Jimenez @ 2020-12-11 16:52 UTC (permalink / raw)
  To: qemu-devel; +Cc: david.edmondson, pbonzini, mihai.carabas

Add a QMP command to allow for the behaviors specified by the
-action event=action command line option to be set at runtime.
The new command is named set-action and takes optional
arguments with an event and a corresponding action to take.

Example:

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

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
 qapi/run-state.json       | 34 ++++++++++++++++++++++++++++++++++
 softmmu/runstate-action.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/qapi/run-state.json b/qapi/run-state.json
index 03ff78b..4732a89 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -453,6 +453,40 @@
 { '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.
+#
+# @panic: @PanicAction action taken on guest panic.
+#
+# @watchdog: @WatchdogAction action taken when watchdog timer expires .
+#
+# Returns: Nothing on success.
+#
+# Since: 6.0
+#
+# Example:
+#
+# -> { "execute": "set-action",
+#      "arguments": { "reboot": "shutdown",
+#                     "shutdown" : "pause",
+#                     "panic": "pause",
+#                     "watchdog": "inject-nmi" } }
+# <- { "return": {} }
+##
+{ 'command': 'set-action',
+  'data': { '*reboot': 'RebootAction',
+            '*shutdown': 'ShutdownAction',
+            '*panic': 'PanicAction',
+            '*watchdog': 'WatchdogAction' },
+  'allow-preconfig': true }
+
+##
 # @GUEST_PANICKED:
 #
 # Emitted when guest OS panic is detected
diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
index bc30102..92feebf 100644
--- a/softmmu/runstate-action.c
+++ b/softmmu/runstate-action.c
@@ -40,6 +40,35 @@ static void fix_panic_action(void)
 }
 
 /*
+ * 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_panic) {
+        panic_action = panic;
+    }
+
+    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;
+        fix_panic_action();
+    }
+}
+
+/*
  * Process an event|action pair and set the appropriate internal
  * state if event and action are valid.
  */
-- 
1.8.3.1



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 4/4] qtest/pvpanic: Test panic option that allows VM to continue
  2020-12-11 16:52 [PATCH v3 0/4] Add a new -action parameter Alejandro Jimenez
                   ` (2 preceding siblings ...)
  2020-12-11 16:52 ` [PATCH v3 3/4] qmp: Allow setting -action parameters on the fly Alejandro Jimenez
@ 2020-12-11 16:52 ` Alejandro Jimenez
  2020-12-11 22:23 ` [PATCH v3 0/4] Add a new -action parameter Paolo Bonzini
  4 siblings, 0 replies; 6+ messages in thread
From: Alejandro Jimenez @ 2020-12-11 16:52 UTC (permalink / raw)
  To: qemu-devel; +Cc: david.edmondson, pbonzini, mihai.carabas

Test the scenario where the -action panic=none parameter is used to
signal that the VM must continue executing after a guest panic
occurs.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
 tests/qtest/pvpanic-test.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/tests/qtest/pvpanic-test.c b/tests/qtest/pvpanic-test.c
index 016b32e..6dcad2d 100644
--- a/tests/qtest/pvpanic-test.c
+++ b/tests/qtest/pvpanic-test.c
@@ -11,13 +11,36 @@
 #include "libqos/libqtest.h"
 #include "qapi/qmp/qdict.h"
 
+static void test_panic_nopause(void)
+{
+    uint8_t val;
+    QDict *response, *data;
+    QTestState *qts;
+
+    qts = qtest_init("-device pvpanic -action panic=none");
+
+    val = qtest_inb(qts, 0x505);
+    g_assert_cmpuint(val, ==, 3);
+
+    qtest_outb(qts, 0x505, 0x1);
+
+    response = qtest_qmp_eventwait_ref(qts, "GUEST_PANICKED");
+    g_assert(qdict_haskey(response, "data"));
+    data = qdict_get_qdict(response, "data");
+    g_assert(qdict_haskey(data, "action"));
+    g_assert_cmpstr(qdict_get_str(data, "action"), ==, "run");
+    qobject_unref(response);
+
+    qtest_quit(qts);
+}
+
 static void test_panic(void)
 {
     uint8_t val;
     QDict *response, *data;
     QTestState *qts;
 
-    qts = qtest_init("-device pvpanic");
+    qts = qtest_init("-device pvpanic -action panic=pause");
 
     val = qtest_inb(qts, 0x505);
     g_assert_cmpuint(val, ==, 3);
@@ -40,6 +63,7 @@ int main(int argc, char **argv)
 
     g_test_init(&argc, &argv, NULL);
     qtest_add_func("/pvpanic/panic", test_panic);
+    qtest_add_func("/pvpanic/panic-nopause", test_panic_nopause);
 
     ret = g_test_run();
 
-- 
1.8.3.1



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 0/4] Add a new -action parameter
  2020-12-11 16:52 [PATCH v3 0/4] Add a new -action parameter Alejandro Jimenez
                   ` (3 preceding siblings ...)
  2020-12-11 16:52 ` [PATCH v3 4/4] qtest/pvpanic: Test panic option that allows VM to continue Alejandro Jimenez
@ 2020-12-11 22:23 ` Paolo Bonzini
  4 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2020-12-11 22:23 UTC (permalink / raw)
  To: Alejandro Jimenez, qemu-devel; +Cc: david.edmondson, mihai.carabas

On 11/12/20 17:52, Alejandro Jimenez wrote:
> This is a follow up to the proposal to add a "-no-panicstop" option to QEMU that would allow us to
> control whether the VM is paused or allowed to continue running without intervention from a management layer
> when a guest panic occurs. See the inital thread and replies for details:
> 
> https://lore.kernel.org/qemu-devel/1601606494-1154-1-git-send-email-alejandro.j.jimenez@oracle.com/
> 
>  From that discussion came a request for a generic mechanism to group options like -no-shutdown, -no-reboot, etc,
> that specify an action taken by QEMU in response to a guest event (reboot, shutdown, panic, and watchdog
> expiration are the current options). The existing options would translate to the new option, like:
> 
> * -no-reboot --> "-action reboot=shutdown"
> * -no-shutdown --> "-action shutdown=pause"
> 
> Please share any questions or comments.

Thanks, this looks good.

(Actually there are a bunch of changes needed for other patches that I 
have queued, but I can take care of that.  Basically, I am moving 
command line parsing from softmmu/runstate-action.c to softmmu/vl.c 
because we're trying to move all command line stuff there + in turn make 
vl.c use QMP commands as much as possible).

Paolo



^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-12-11 23:08 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2020-12-11 16:52 [PATCH v3 0/4] Add a new -action parameter Alejandro Jimenez
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2020-12-11 16:52 ` [PATCH v3 2/4] vl: Add option to avoid stopping VM upon guest panic Alejandro Jimenez
2020-12-11 16:52 ` [PATCH v3 3/4] qmp: Allow setting -action parameters on the fly Alejandro Jimenez
2020-12-11 16:52 ` [PATCH v3 4/4] qtest/pvpanic: Test panic option that allows VM to continue Alejandro Jimenez
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