[PATCH v2 0/4] Add a new -action parameter

[PATCH v2 0/4] Add a new -action parameter

[Alejandro Jimenez]

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 |  16 ++++
 include/sysemu/sysemu.h          |   2 +
 qapi/run-state.json              | 135 +++++++++++++++++++++++++++++
 qemu-options.hx                  |  25 ++++++
 softmmu/meson.build              |   1 +
 softmmu/runstate-action.c        | 182 +++++++++++++++++++++++++++++++++++++++
 softmmu/vl.c                     |  44 +++++++++-
 tests/qtest/pvpanic-test.c       |  26 +++++-
 9 files changed, 428 insertions(+), 5 deletions(-)
 create mode 100644 include/sysemu/runstate-action.h
 create mode 100644 softmmu/runstate-action.c

-- 
1.8.3.1

[PATCH v2 1/4] vl: Add an -action option to respond to guest events

[Alejandro Jimenez]

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 |  16 +++++
 include/sysemu/sysemu.h          |   1 +
 qapi/run-state.json              |  88 ++++++++++++++++++++++++++
 qemu-options.hx                  |  22 +++++++
 softmmu/meson.build              |   1 +
 softmmu/runstate-action.c        | 131 +++++++++++++++++++++++++++++++++++++++
 softmmu/vl.c                     |  30 ++++++++-
 8 files changed, 290 insertions(+), 1 deletion(-)
 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..f545ab3
--- /dev/null
+++ b/include/sysemu/runstate-action.h
@@ -0,0 +1,16 @@
+/*
+ * 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
+
+/* in softmmu/runstate-action.c */
+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..5480e61 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -43,6 +43,7 @@ extern int win2k_install_hack;
 extern int alt_grab;
 extern int ctrl_grab;
 extern int graphic_rotate;
+extern int no_reboot;
 extern int no_shutdown;
 extern int old_param;
 extern int boot_menu;
diff --git a/qapi/run-state.json b/qapi/run-state.json
index 964c8ef..6b033c1 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -329,6 +329,94 @@
             '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:
+#
+# @pause: pause the VM
+#
+# @poweroff: Shutdown the VM and exit
+#
+# Since: 6.0
+##
+{ 'enum': 'ShutdownAction',
+  'data': [ 'pause', 'poweroff' ] }
+
+##
+# @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..f1fd457
--- /dev/null
+++ b/softmmu/runstate-action.c
@@ -0,0 +1,131 @@
+/*
+ * 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/sysemu.h"
+#include "sysemu/watchdog.h"
+#include "qemu/config-file.h"
+#include "qapi/error.h"
+#include "qemu/option_int.h"
+#include "qapi/qapi-commands-run-state.h"
+
+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));
+    }
+}
+
+/*
+ * Set the internal state to react to a guest reboot event
+ * as specified by the action parameter.
+ */
+static void reboot_set_action(RebootAction act, Error **errp)
+{
+    switch (act) {
+    case REBOOT_ACTION_NONE:
+        no_reboot = 0;
+        break;
+    case REBOOT_ACTION_SHUTDOWN:
+        no_reboot = 1;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+/*
+ * Set the internal state to react to a guest shutdown event
+ * as specified by the action parameter.
+ */
+static void shutdown_set_action(ShutdownAction act, Error **errp)
+{
+    switch (act) {
+    case SHUTDOWN_ACTION_PAUSE:
+        no_shutdown = 1;
+        break;
+    case SHUTDOWN_ACTION_POWEROFF:
+        no_shutdown = 0;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+/*
+ * 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, act_idx;
+
+    event_idx = qapi_enum_parse(&RunStateEventType_lookup, event, -1, errp);
+
+    switch (event_idx) {
+    case RUN_STATE_EVENT_TYPE_REBOOT:
+        act_idx = qapi_enum_parse(&RebootAction_lookup, action, -1, errp);
+        reboot_set_action(act_idx, NULL);
+        break;
+    case RUN_STATE_EVENT_TYPE_SHUTDOWN:
+        act_idx = qapi_enum_parse(&ShutdownAction_lookup, action, -1, errp);
+        shutdown_set_action(act_idx, NULL);
+        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..2b1583e 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"
@@ -147,7 +148,7 @@ Chardev *parallel_hds[MAX_PARALLEL_PORTS];
 int win2k_install_hack = 0;
 int singlestep = 0;
 int fd_bootchk = 1;
-static int no_reboot;
+int no_reboot;
 int no_shutdown = 0;
 int graphic_rotate = 0;
 const char *watchdog;
@@ -506,6 +507,21 @@ 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
  *
@@ -2948,6 +2964,7 @@ 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 +3437,12 @@ 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");
@@ -3902,6 +3925,11 @@ 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);
-- 
1.8.3.1

[PATCH v2 2/4] vl: Add option to avoid stopping VM upon guest panic

[Alejandro Jimenez]

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/sysemu.h   |  1 +
 qapi/run-state.json       | 27 ++++++++++++++++++++++++++-
 qemu-options.hx           |  3 +++
 softmmu/runstate-action.c | 22 ++++++++++++++++++++++
 softmmu/vl.c              | 14 +++++++++++---
 5 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 5480e61..863142e 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -45,6 +45,7 @@ extern int ctrl_grab;
 extern int graphic_rotate;
 extern int no_reboot;
 extern int no_shutdown;
+extern int pause_on_panic;
 extern int old_param;
 extern int boot_menu;
 extern bool boot_strict;
diff --git a/qapi/run-state.json b/qapi/run-state.json
index 6b033c1..27b62ce 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' } }
 
 ##
@@ -407,6 +410,28 @@
   'data': [ 'pause', 'poweroff' ] }
 
 ##
+# @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': [ 'none', 'pause' ] }
+
+##
 # @RunStateWatchdogAction:
 #
 # @action: Action taken by QEMU when watchdog device timer expires
diff --git a/qemu-options.hx b/qemu-options.hx
index a0d50f0..8b7d8bb 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=pause|none\n"
+    "                   action when guest panics [default=pause]\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 f1fd457..a644d80 100644
--- a/softmmu/runstate-action.c
+++ b/softmmu/runstate-action.c
@@ -62,6 +62,24 @@ static void shutdown_set_action(ShutdownAction act, Error **errp)
 }
 
 /*
+ * Set the internal state to react to a guest panic event
+ * as specified by the action parameter.
+ */
+static void panic_set_action(PanicAction action, Error **errp)
+{
+    switch (action) {
+    case PANIC_ACTION_NONE:
+        pause_on_panic = 0;
+        break;
+    case PANIC_ACTION_PAUSE:
+        pause_on_panic = 1;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+/*
  * Process an event|action pair and set the appropriate internal
  * state if event and action are valid.
  */
@@ -81,6 +99,10 @@ static int set_runstate_action(void *opaque, const char *event,
         act_idx = qapi_enum_parse(&ShutdownAction_lookup, action, -1, errp);
         shutdown_set_action(act_idx, NULL);
         break;
+    case RUN_STATE_EVENT_TYPE_PANIC:
+        act_idx = qapi_enum_parse(&PanicAction_lookup, action, -1, errp);
+        panic_set_action(act_idx, NULL);
+        break;
     case RUN_STATE_EVENT_TYPE_WATCHDOG:
         if (select_watchdog_action(action) == -1) {
             error_report("invalid parameter value: %s", action);
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 2b1583e..20f89cb 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -150,6 +150,7 @@ int singlestep = 0;
 int fd_bootchk = 1;
 int no_reboot;
 int no_shutdown = 0;
+int pause_on_panic = 1;
 int graphic_rotate = 0;
 const char *watchdog;
 QEMUOptionRom option_rom[MAX_OPTION_ROMS];
@@ -1449,9 +1450,16 @@ 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 (pause_on_panic) {
+        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 (!no_shutdown) {
         qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_POWEROFF,
                                        !!info, info);
-- 
1.8.3.1

[PATCH v2 3/4] qmp: Allow setting -action parameters on the fly

[Alejandro Jimenez]

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 a single argument
of type RunStateAction, which contains an event|action pair.

Example:

-> { "execute": "set-action",
     "arguments": { "pair": {
         "event": "shutdown",
	  "action": "pause" } } }
<- { "return": {} }

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
 qapi/run-state.json       | 22 ++++++++++++++++++++++
 softmmu/runstate-action.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/qapi/run-state.json b/qapi/run-state.json
index 27b62ce..ead9dab 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -451,6 +451,28 @@
 { 'command': 'watchdog-set-action', 'data' : {'action': 'WatchdogAction'} }
 
 ##
+# @set-action:
+#
+# Set the action that will be taken by the emulator in response to a guest
+# event.
+#
+# @pair: a @RunStateAction type that describes an event|action pair.
+#
+# Returns: Nothing on success.
+#
+# Since: 6.0
+#
+# Example:
+#
+# -> { "execute": "set-action",
+#         "arguments": { "pair": {
+#             "event": "shutdown",
+#             "action": "pause" } } }
+# <- { "return": {} }
+##
+{ 'command': 'set-action', 'data' : {'pair': 'RunStateAction'} }
+
+##
 # @GUEST_PANICKED:
 #
 # Emitted when guest OS panic is detected
diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
index a644d80..7877e7e 100644
--- a/softmmu/runstate-action.c
+++ b/softmmu/runstate-action.c
@@ -80,6 +80,35 @@ static void panic_set_action(PanicAction action, Error **errp)
 }
 
 /*
+ * Receives a RunStateAction type which represents an event|action pair
+ * and sets the internal state as requested.
+ */
+void qmp_set_action(RunStateAction *pair, Error **errp)
+{
+    switch (pair->event) {
+    case RUN_STATE_EVENT_TYPE_REBOOT:
+        reboot_set_action(pair->u.reboot.action, NULL);
+        break;
+    case RUN_STATE_EVENT_TYPE_SHUTDOWN:
+        shutdown_set_action(pair->u.shutdown.action, NULL);
+        break;
+    case RUN_STATE_EVENT_TYPE_PANIC:
+        panic_set_action(pair->u.panic.action, NULL);
+        break;
+    case RUN_STATE_EVENT_TYPE_WATCHDOG:
+        qmp_watchdog_set_action(pair->u.watchdog.action, NULL);
+        break;
+    default:
+        /*
+         * The fields in the RunStateAction argument are validated
+         * by the QMP marshalling code before this function is called.
+         * This case is unreachable unless new variants are added.
+         */
+        g_assert_not_reached();
+    }
+}
+
+/*
  * Process an event|action pair and set the appropriate internal
  * state if event and action are valid.
  */
-- 
1.8.3.1

[PATCH v2 4/4] qtest/pvpanic: Test panic option that allows VM to continue

[Alejandro Jimenez]

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

Re: [PATCH v2 3/4] qmp: Allow setting -action parameters on the fly

[Paolo Bonzini]

On 09/12/20 18:52, Alejandro Jimenez wrote:
> +# Set the action that will be taken by the emulator in response to a guest
> +# event.
> +#
> +# @pair: a @RunStateAction type that describes an event|action pair.
> +#
> +# Returns: Nothing on success.
> +#
> +# Since: 6.0
> +#
> +# Example:
> +#
> +# -> { "execute": "set-action",
> +#         "arguments": { "pair": {
> +#             "event": "shutdown",
> +#             "action": "pause" } } }
> +# <- { "return": {} }
> +##
> +{ 'command': 'set-action', 'data' : {'pair': 'RunStateAction'} }
> +
> +##
>   # @GUEST_PANICKED:
>   #
>   # Emitted when guest OS panic is detected
> diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
> index a644d80..7877e7e 100644
> --- a/softmmu/runstate-action.c
> +++ b/softmmu/runstate-action.c
> @@ -80,6 +80,35 @@ static void panic_set_action(PanicAction action, Error **errp)
>   }
>   
>   /*
> + * Receives a RunStateAction type which represents an event|action pair
> + * and sets the internal state as requested.
> + */
> +void qmp_set_action(RunStateAction *pair, Error **errp)
> +{
> +    switch (pair->event) {
> +    case RUN_STATE_EVENT_TYPE_REBOOT:
> +        reboot_set_action(pair->u.reboot.action, NULL);
> +        break;
> +    case RUN_STATE_EVENT_TYPE_SHUTDOWN:
> +        shutdown_set_action(pair->u.shutdown.action, NULL);
> +        break;
> +    case RUN_STATE_EVENT_TYPE_PANIC:
> +        panic_set_action(pair->u.panic.action, NULL);
> +        break;
> +    case RUN_STATE_EVENT_TYPE_WATCHDOG:
> +        qmp_watchdog_set_action(pair->u.watchdog.action, NULL);
> +        break;
> +    default:
> +        /*
> +         * The fields in the RunStateAction argument are validated
> +         * by the QMP marshalling code before this function is called.
> +         * This case is unreachable unless new variants are added.
> +         */
> +        g_assert_not_reached();
> +    }
> +}
> +

Any reason not to have the multiple optional arguments as discussed in 
v1 (no reply usually means you agree)?  The implementation would be 
nice, like

     if (actions->has_reboot) {
         reboot_set_action(actions->reboot);
     }
     etc.

?

Note that, in patches 1-2, you don't need to add an Error** argument to 
functions that cannot fail.

Thanks,

Paolo

Re: [PATCH v2 1/4] vl: Add an -action option to respond to guest events

[Paolo Bonzini]

On 09/12/20 18:52, Alejandro Jimenez wrote:
> -static int no_reboot;
> +int no_reboot;
>   int no_shutdown = 0;

Since you are at it, please move these globals to the new file.

Paolo

Re: [PATCH v2 2/4] vl: Add option to avoid stopping VM upon guest panic

[Paolo Bonzini]

On 09/12/20 18:52, Alejandro Jimenez wrote:
> -    vm_stop(RUN_STATE_GUEST_PANICKED);
> +
> +    if (pause_on_panic) {
> +        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 (!no_shutdown) {
>           qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_POWEROFF,
>                                          !!info, info);

The "if" below suggests making -action panic's argument a tri-state 
(none/pause/poweroff; default is poweroff and -no-shutdown becomes 
equivalent to -action shutdown=pause,panic=pause).

In principle debug and reset could be supported as well, so maybe add a 
TODO comment.

Paolo

Re: [PATCH v2 3/4] qmp: Allow setting -action parameters on the fly

[Alejandro Jimenez]

On 12/9/2020 4:43 PM, Paolo Bonzini wrote:
> On 09/12/20 18:52, Alejandro Jimenez wrote:
>> +# Set the action that will be taken by the emulator in response to a 
>> guest
>> +# event.
>> +#
>> +# @pair: a @RunStateAction type that describes an event|action pair.
>> +#
>> +# Returns: Nothing on success.
>> +#
>> +# Since: 6.0
>> +#
>> +# Example:
>> +#
>> +# -> { "execute": "set-action",
>> +#         "arguments": { "pair": {
>> +#             "event": "shutdown",
>> +#             "action": "pause" } } }
>> +# <- { "return": {} }
>> +##
>> +{ 'command': 'set-action', 'data' : {'pair': 'RunStateAction'} }
>> +
>> +##
>>   # @GUEST_PANICKED:
>>   #
>>   # Emitted when guest OS panic is detected
>> diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
>> index a644d80..7877e7e 100644
>> --- a/softmmu/runstate-action.c
>> +++ b/softmmu/runstate-action.c
>> @@ -80,6 +80,35 @@ static void panic_set_action(PanicAction action, 
>> Error **errp)
>>   }
>>     /*
>> + * Receives a RunStateAction type which represents an event|action pair
>> + * and sets the internal state as requested.
>> + */
>> +void qmp_set_action(RunStateAction *pair, Error **errp)
>> +{
>> +    switch (pair->event) {
>> +    case RUN_STATE_EVENT_TYPE_REBOOT:
>> +        reboot_set_action(pair->u.reboot.action, NULL);
>> +        break;
>> +    case RUN_STATE_EVENT_TYPE_SHUTDOWN:
>> +        shutdown_set_action(pair->u.shutdown.action, NULL);
>> +        break;
>> +    case RUN_STATE_EVENT_TYPE_PANIC:
>> +        panic_set_action(pair->u.panic.action, NULL);
>> +        break;
>> +    case RUN_STATE_EVENT_TYPE_WATCHDOG:
>> +        qmp_watchdog_set_action(pair->u.watchdog.action, NULL);
>> +        break;
>> +    default:
>> +        /*
>> +         * The fields in the RunStateAction argument are validated
>> +         * by the QMP marshalling code before this function is called.
>> +         * This case is unreachable unless new variants are added.
>> +         */
>> +        g_assert_not_reached();
>> +    }
>> +}
>> +
>
> Any reason not to have the multiple optional arguments as discussed in 
> v1 (no reply usually means you agree)?  The implementation would be 
> nice, like
>
>     if (actions->has_reboot) {
>         reboot_set_action(actions->reboot);
>     }
>     etc.
>
> ?
I misunderstood your request in v1. I'll try to be explicit to avoid 
more confusion. Are you expecting a command of the form:

{ 'command': 'set-action',
'data' : {
     '*reboot': 'RebootAction',
     '*shutdown': 'ShutdownAction',
     '*panic': 'PanicAction',
     '*watchdog': 'WatchdogAction' } }
?

Or is it better to encapsulate all of those optional fields inside a new 
struct definition (RunStateActions?) so that the command would be:

{ 'command': 'set-action', 'data': 'actions' : 'RunStateActions' }

which is what the "actions->has_reboot" example seems to suggest?

Or is it something else that I am not understanding yet?

>
> Note that, in patches 1-2, you don't need to add an Error** argument 
> to functions that cannot fail.
This was left over from the initial patch. I'll fix it.

Alejandro
>
> Thanks,
>
> Paolo
>

Re: [PATCH v2 3/4] qmp: Allow setting -action parameters on the fly

[Paolo Bonzini]

On 10/12/20 04:21, Alejandro Jimenez wrote:
> I misunderstood your request in v1. 

Oh ypu're right, in v1 you had multiple commands.  My fault then.

> 
> { 'command': 'set-action',
> 'data' : {
>      '*reboot': 'RebootAction',
>      '*shutdown': 'ShutdownAction',
>      '*panic': 'PanicAction',
>      '*watchdog': 'WatchdogAction' } }
> ?
> 
> Or is it better to encapsulate all of those optional fields inside a new 
> struct definition (RunStateActions?) so that the command would be:
> 
> { 'command': 'set-action', 'data': 'actions' : 'RunStateActions' }

Any of the two is fine; the QMP stream is the same.  I used 
actions->reboot because that's what you did in v2.

While at it, you might add

    'allow-preconfig': true,

as well.  (Right now there are relatively few allow-preconfig commands, 
but I'm in the process of adding it to all commands where it makes sense).

Thanks,

Paolo