[Qemu-devel] [PATCH v3 0/2] watchdog: Allow setting action on the fly

[Qemu-devel] [PATCH v3 0/2] watchdog: Allow setting action on the fly

[Michal Privoznik]

diff to v2:
- Introduced 1/2 patch that renames WatchdogExpirationAction
- Better handling of unknown state in switch()
- Passs &error_abort to qmp_watchdog_set_action()

Michal Privoznik (2):
  qapi: Rename WatchdogExpirationAction enum
  watchdog: Allow setting action on the fly

 hw/watchdog/watchdog.c    | 64 +++++++++++++++++++++++------------------------
 hw/watchdog/wdt_diag288.c |  6 ++---
 include/sysemu/watchdog.h | 12 ++-------
 monitor.c                 |  4 +--
 qapi-schema.json          |  9 +++++++
 qapi/run-state.json       |  6 ++---
 6 files changed, 51 insertions(+), 50 deletions(-)

-- 
2.13.5

[Qemu-devel] [PATCH v3 1/2] qapi: Rename WatchdogExpirationAction enum

[Michal Privoznik]

The new name is WatchdogAction which is shorter,

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 hw/watchdog/watchdog.c | 14 +++++++-------
 monitor.c              |  4 ++--
 qapi/run-state.json    |  6 +++---
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/hw/watchdog/watchdog.c b/hw/watchdog/watchdog.c
index 0c5c9cde1c..358d79804d 100644
--- a/hw/watchdog/watchdog.c
+++ b/hw/watchdog/watchdog.c
@@ -109,17 +109,17 @@ void watchdog_perform_action(void)
 {
     switch (watchdog_action) {
     case WDT_RESET:             /* same as 'system_reset' in monitor */
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_RESET, &error_abort);
+        qapi_event_send_watchdog(WATCHDOG_ACTION_RESET, &error_abort);
         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
         break;
 
     case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_SHUTDOWN, &error_abort);
+        qapi_event_send_watchdog(WATCHDOG_ACTION_SHUTDOWN, &error_abort);
         qemu_system_powerdown_request();
         break;
 
     case WDT_POWEROFF:          /* same as 'quit' command in monitor */
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_POWEROFF, &error_abort);
+        qapi_event_send_watchdog(WATCHDOG_ACTION_POWEROFF, &error_abort);
         exit(0);
 
     case WDT_PAUSE:             /* same as 'stop' command in monitor */
@@ -127,21 +127,21 @@ void watchdog_perform_action(void)
          * you would get a deadlock.  Bypass the problem.
          */
         qemu_system_vmstop_request_prepare();
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_PAUSE, &error_abort);
+        qapi_event_send_watchdog(WATCHDOG_ACTION_PAUSE, &error_abort);
         qemu_system_vmstop_request(RUN_STATE_WATCHDOG);
         break;
 
     case WDT_DEBUG:
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_DEBUG, &error_abort);
+        qapi_event_send_watchdog(WATCHDOG_ACTION_DEBUG, &error_abort);
         fprintf(stderr, "watchdog: timer fired\n");
         break;
 
     case WDT_NONE:
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_NONE, &error_abort);
+        qapi_event_send_watchdog(WATCHDOG_ACTION_NONE, &error_abort);
         break;
 
     case WDT_NMI:
-        qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_INJECT_NMI,
+        qapi_event_send_watchdog(WATCHDOG_ACTION_INJECT_NMI,
                                  &error_abort);
         nmi_monitor_handle(0, NULL);
         break;
diff --git a/monitor.c b/monitor.c
index 9239f7adde..e6a6675c15 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3537,8 +3537,8 @@ void watchdog_action_completion(ReadLineState *rs, int nb_args, const char *str)
         return;
     }
     readline_set_completion_index(rs, strlen(str));
-    for (i = 0; i < WATCHDOG_EXPIRATION_ACTION__MAX; i++) {
-        add_completion_option(rs, str, WatchdogExpirationAction_str(i));
+    for (i = 0; i < WATCHDOG_ACTION__MAX; i++) {
+        add_completion_option(rs, str, WatchdogAction_str(i));
     }
 }
 
diff --git a/qapi/run-state.json b/qapi/run-state.json
index d36ff49834..bca46a8785 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -253,10 +253,10 @@
 #
 ##
 { 'event': 'WATCHDOG',
-  'data': { 'action': 'WatchdogExpirationAction' } }
+  'data': { 'action': 'WatchdogAction' } }
 
 ##
-# @WatchdogExpirationAction:
+# @WatchdogAction:
 #
 # An enumeration of the actions taken when the watchdog device's timer is
 # expired
@@ -279,7 +279,7 @@
 #
 # Since: 2.1
 ##
-{ 'enum': 'WatchdogExpirationAction',
+{ 'enum': 'WatchdogAction',
   'data': [ 'reset', 'shutdown', 'poweroff', 'pause', 'debug', 'none',
             'inject-nmi' ] }
 
-- 
2.13.5

[Qemu-devel] [PATCH v3 2/2] watchdog: Allow setting action on the fly

[Michal Privoznik]

Currently, the only time that users can set watchdog action is at
the start as all we expose is this -watchdog-action command line
argument. This is suboptimal when users want to plug the device
later via monitor. Alternatively, they might want to change the
action for already existing device on the fly.

At the same time, drop local redefinition of the actions enum in
watchdog.h in favour of the ones defined in schema and thus kills
code duplication.

Inspired by: https://bugzilla.redhat.com/show_bug.cgi?id=1447169

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 hw/watchdog/watchdog.c    | 50 +++++++++++++++++++++++------------------------
 hw/watchdog/wdt_diag288.c |  6 +++---
 include/sysemu/watchdog.h | 12 ++----------
 qapi-schema.json          |  9 +++++++++
 4 files changed, 39 insertions(+), 38 deletions(-)

diff --git a/hw/watchdog/watchdog.c b/hw/watchdog/watchdog.c
index 358d79804d..2d21eaba28 100644
--- a/hw/watchdog/watchdog.c
+++ b/hw/watchdog/watchdog.c
@@ -29,8 +29,11 @@
 #include "qapi-event.h"
 #include "hw/nmi.h"
 #include "qemu/help_option.h"
+#include "qmp-commands.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi/util.h"
 
-static int watchdog_action = WDT_RESET;
+static WatchdogAction watchdog_action = WATCHDOG_ACTION_RESET;
 static QLIST_HEAD(watchdog_list, WatchdogTimerModel) watchdog_list;
 
 void watchdog_add_model(WatchdogTimerModel *model)
@@ -77,27 +80,16 @@ int select_watchdog(const char *p)
 
 int select_watchdog_action(const char *p)
 {
-    if (strcasecmp(p, "reset") == 0)
-        watchdog_action = WDT_RESET;
-    else if (strcasecmp(p, "shutdown") == 0)
-        watchdog_action = WDT_SHUTDOWN;
-    else if (strcasecmp(p, "poweroff") == 0)
-        watchdog_action = WDT_POWEROFF;
-    else if (strcasecmp(p, "pause") == 0)
-        watchdog_action = WDT_PAUSE;
-    else if (strcasecmp(p, "debug") == 0)
-        watchdog_action = WDT_DEBUG;
-    else if (strcasecmp(p, "none") == 0)
-        watchdog_action = WDT_NONE;
-    else if (strcasecmp(p, "inject-nmi") == 0)
-        watchdog_action = WDT_NMI;
-    else
-        return -1;
+    int action;
 
+    action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL);
+    if (action < 0)
+        return -1;
+    qmp_watchdog_set_action(action, &error_abort);
     return 0;
 }
 
-int get_watchdog_action(void)
+WatchdogAction get_watchdog_action(void)
 {
     return watchdog_action;
 }
@@ -108,21 +100,21 @@ int get_watchdog_action(void)
 void watchdog_perform_action(void)
 {
     switch (watchdog_action) {
-    case WDT_RESET:             /* same as 'system_reset' in monitor */
+    case WATCHDOG_ACTION_RESET:      /* same as 'system_reset' in monitor */
         qapi_event_send_watchdog(WATCHDOG_ACTION_RESET, &error_abort);
         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
         break;
 
-    case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
+    case WATCHDOG_ACTION_SHUTDOWN:   /* same as 'system_powerdown' in monitor */
         qapi_event_send_watchdog(WATCHDOG_ACTION_SHUTDOWN, &error_abort);
         qemu_system_powerdown_request();
         break;
 
-    case WDT_POWEROFF:          /* same as 'quit' command in monitor */
+    case WATCHDOG_ACTION_POWEROFF:   /* same as 'quit' command in monitor */
         qapi_event_send_watchdog(WATCHDOG_ACTION_POWEROFF, &error_abort);
         exit(0);
 
-    case WDT_PAUSE:             /* same as 'stop' command in monitor */
+    case WATCHDOG_ACTION_PAUSE:      /* same as 'stop' command in monitor */
         /* In a timer callback, when vm_stop calls qemu_clock_enable
          * you would get a deadlock.  Bypass the problem.
          */
@@ -131,19 +123,27 @@ void watchdog_perform_action(void)
         qemu_system_vmstop_request(RUN_STATE_WATCHDOG);
         break;
 
-    case WDT_DEBUG:
+    case WATCHDOG_ACTION_DEBUG:
         qapi_event_send_watchdog(WATCHDOG_ACTION_DEBUG, &error_abort);
         fprintf(stderr, "watchdog: timer fired\n");
         break;
 
-    case WDT_NONE:
+    case WATCHDOG_ACTION_NONE:
         qapi_event_send_watchdog(WATCHDOG_ACTION_NONE, &error_abort);
         break;
 
-    case WDT_NMI:
+    case WATCHDOG_ACTION_INJECT_NMI:
         qapi_event_send_watchdog(WATCHDOG_ACTION_INJECT_NMI,
                                  &error_abort);
         nmi_monitor_handle(0, NULL);
         break;
+
+    default:
+        assert(0);
     }
 }
+
+void qmp_watchdog_set_action(WatchdogAction action, Error **errp)
+{
+    watchdog_action = action;
+}
diff --git a/hw/watchdog/wdt_diag288.c b/hw/watchdog/wdt_diag288.c
index 47f289216a..1475743527 100644
--- a/hw/watchdog/wdt_diag288.c
+++ b/hw/watchdog/wdt_diag288.c
@@ -57,9 +57,9 @@ static void diag288_timer_expired(void *dev)
      * the BQL; reset before triggering the action to avoid races with
      * diag288 instructions. */
     switch (get_watchdog_action()) {
-    case WDT_DEBUG:
-    case WDT_NONE:
-    case WDT_PAUSE:
+    case WATCHDOG_ACTION_DEBUG:
+    case WATCHDOG_ACTION_NONE:
+    case WATCHDOG_ACTION_PAUSE:
         break;
     default:
         wdt_diag288_reset(dev);
diff --git a/include/sysemu/watchdog.h b/include/sysemu/watchdog.h
index 72a4da07a6..677ace3945 100644
--- a/include/sysemu/watchdog.h
+++ b/include/sysemu/watchdog.h
@@ -23,15 +23,7 @@
 #define QEMU_WATCHDOG_H
 
 #include "qemu/queue.h"
-
-/* Possible values for action parameter. */
-#define WDT_RESET        1      /* Hard reset. */
-#define WDT_SHUTDOWN     2      /* Shutdown. */
-#define WDT_POWEROFF     3      /* Quit. */
-#define WDT_PAUSE        4      /* Pause. */
-#define WDT_DEBUG        5      /* Prints a message and continues running. */
-#define WDT_NONE         6      /* Do nothing. */
-#define WDT_NMI          7      /* Inject nmi into the guest. */
+#include "qapi-types.h"
 
 struct WatchdogTimerModel {
     QLIST_ENTRY(WatchdogTimerModel) entry;
@@ -46,7 +38,7 @@ typedef struct WatchdogTimerModel WatchdogTimerModel;
 /* in hw/watchdog.c */
 int select_watchdog(const char *p);
 int select_watchdog_action(const char *action);
-int get_watchdog_action(void);
+WatchdogAction get_watchdog_action(void);
 void watchdog_add_model(WatchdogTimerModel *model);
 void watchdog_perform_action(void);
 
diff --git a/qapi-schema.json b/qapi-schema.json
index f3af2cb851..f5db401838 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3143,3 +3143,12 @@
 # Since 2.9
 ##
 { 'command': 'query-vm-generation-id', 'returns': 'GuidInfo' }
+
+##
+# @watchdog-set-action:
+#
+# Set watchdog action
+#
+# Since 2.11
+##
+{ 'command': 'watchdog-set-action', 'data' : {'action': 'WatchdogAction'} }
-- 
2.13.5

Re: [Qemu-devel] [PATCH v3 2/2] watchdog: Allow setting action on the fly

[Daniel P. Berrange]

On Wed, Sep 06, 2017 at 10:58:54AM +0200, Michal Privoznik wrote:
> Currently, the only time that users can set watchdog action is at
> the start as all we expose is this -watchdog-action command line
> argument. This is suboptimal when users want to plug the device
> later via monitor. Alternatively, they might want to change the
> action for already existing device on the fly.
> 
> At the same time, drop local redefinition of the actions enum in
> watchdog.h in favour of the ones defined in schema and thus kills
> code duplication.

Nit-pick - I'd suggest 2 separat patches - one that drops the enum
redefinition, and the second which adds the new monitor command.
That way you separate no-op refactoring, from new features.


Regards,
Daniel
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Re: [Qemu-devel] [PATCH v3 2/2] watchdog: Allow setting action on the fly

[Michal Privoznik]

On 09/06/2017 11:04 AM, Daniel P. Berrange wrote:
> On Wed, Sep 06, 2017 at 10:58:54AM +0200, Michal Privoznik wrote:
>> Currently, the only time that users can set watchdog action is at
>> the start as all we expose is this -watchdog-action command line
>> argument. This is suboptimal when users want to plug the device
>> later via monitor. Alternatively, they might want to change the
>> action for already existing device on the fly.
>>
>> At the same time, drop local redefinition of the actions enum in
>> watchdog.h in favour of the ones defined in schema and thus kills
>> code duplication.
> 
> Nit-pick - I'd suggest 2 separat patches - one that drops the enum
> redefinition, and the second which adds the new monitor command.
> That way you separate no-op refactoring, from new features.

Sure. We prefer that in libvirt too. Let me respin v4.

Michal