[libvirt] [PATCH] qemu: Honour <on_reboot/>

Michal Privoznik mprivozn at redhat.com
Thu Aug 3 07:36:27 UTC 2017


https://bugzilla.redhat.com/show_bug.cgi?id=1476866

For some reason, we completely ignore <on_reboot/> setting for
domains. The implementation is simply not there. It never was.
However, things are slightly more complicated. QEMU sends us two
RESET events on domain reboot. Fortunately, the event contains
this 'guest' field telling us who initiated the reboot. And since
we don't want to destroy the domain if the reset is initiated by
a user, we have to ignore those events. Whatever, just look at
the code.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_domain.h       |  1 +
 src/qemu/qemu_monitor.c      |  4 ++--
 src/qemu/qemu_monitor.h      |  3 ++-
 src/qemu/qemu_monitor_json.c |  8 +++++++-
 src/qemu/qemu_process.c      | 34 ++++++++++++++++++++++++++++++----
 5 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 4c9050aff..d865e67c7 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -233,6 +233,7 @@ struct _qemuDomainObjPrivate {
     bool agentError;
 
     bool gotShutdown;
+    bool gotReset;
     bool beingDestroyed;
     char *pidfile;
 
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 19082d8bf..8f81a2b28 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -1344,12 +1344,12 @@ qemuMonitorEmitShutdown(qemuMonitorPtr mon, virTristateBool guest)
 
 
 int
-qemuMonitorEmitReset(qemuMonitorPtr mon)
+qemuMonitorEmitReset(qemuMonitorPtr mon, virTristateBool guest)
 {
     int ret = -1;
     VIR_DEBUG("mon=%p", mon);
 
-    QEMU_MONITOR_CALLBACK(mon, ret, domainReset, mon->vm);
+    QEMU_MONITOR_CALLBACK(mon, ret, domainReset, mon->vm, guest);
     return ret;
 }
 
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 31f7e97ba..8c33f6783 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -134,6 +134,7 @@ typedef int (*qemuMonitorDomainShutdownCallback)(qemuMonitorPtr mon,
                                                  void *opaque);
 typedef int (*qemuMonitorDomainResetCallback)(qemuMonitorPtr mon,
                                               virDomainObjPtr vm,
+                                              virTristateBool guest,
                                               void *opaque);
 typedef int (*qemuMonitorDomainPowerdownCallback)(qemuMonitorPtr mon,
                                                   virDomainObjPtr vm,
@@ -346,7 +347,7 @@ int qemuMonitorEmitEvent(qemuMonitorPtr mon, const char *event,
                          long long seconds, unsigned int micros,
                          const char *details);
 int qemuMonitorEmitShutdown(qemuMonitorPtr mon, virTristateBool guest);
-int qemuMonitorEmitReset(qemuMonitorPtr mon);
+int qemuMonitorEmitReset(qemuMonitorPtr mon, virTristateBool guest);
 int qemuMonitorEmitPowerdown(qemuMonitorPtr mon);
 int qemuMonitorEmitStop(qemuMonitorPtr mon);
 int qemuMonitorEmitResume(qemuMonitorPtr mon);
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index b8a68154a..8a1501ced 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -536,7 +536,13 @@ static void qemuMonitorJSONHandleShutdown(qemuMonitorPtr mon, virJSONValuePtr da
 
 static void qemuMonitorJSONHandleReset(qemuMonitorPtr mon, virJSONValuePtr data ATTRIBUTE_UNUSED)
 {
-    qemuMonitorEmitReset(mon);
+    bool guest = false;
+    virTristateBool guest_initiated = VIR_TRISTATE_BOOL_ABSENT;
+
+    if (data && virJSONValueObjectGetBoolean(data, "guest", &guest) == 0)
+        guest_initiated = guest ? VIR_TRISTATE_BOOL_YES : VIR_TRISTATE_BOOL_NO;
+
+    qemuMonitorEmitReset(mon, guest_initiated);
 }
 
 static void qemuMonitorJSONHandlePowerdown(qemuMonitorPtr mon, virJSONValuePtr data ATTRIBUTE_UNUSED)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 0aecce3b1..889efc7f0 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -478,27 +478,51 @@ qemuProcessFindVolumeQcowPassphrase(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
 static int
 qemuProcessHandleReset(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
                        virDomainObjPtr vm,
+                       virTristateBool guest_initiated,
                        void *opaque)
 {
     virQEMUDriverPtr driver = opaque;
-    virObjectEventPtr event;
+    virObjectEventPtr event = NULL;
     qemuDomainObjPrivatePtr priv;
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+    bool callOnReboot = false;
 
     virObjectLock(vm);
 
+    priv = vm->privateData;
+
+    /* This is a bit tricky. When a guest does 'reboot' we receive RESET event
+     * twice, both times it's guest initiated. However, if users call 'virsh
+     * reset' we still receive two events but the first one is guest_initiated
+     * = no, the second one is guest_initiated = yes. Therefore, to avoid
+     * executing onReboot action in the latter case we need this complicated
+     * construction. */
+    if (guest_initiated == VIR_TRISTATE_BOOL_NO) {
+        VIR_DEBUG("Ignoring not guest initiated RESET event from domain %s",
+                  vm->def->name);
+        priv->gotReset = true;
+    } else if (priv->gotReset && guest_initiated == VIR_TRISTATE_BOOL_YES) {
+        VIR_DEBUG("Ignoring second RESET event from domain %s",
+                  vm->def->name);
+        priv->gotReset = false;
+    } else {
+        callOnReboot = true;
+    }
+
     event = virDomainEventRebootNewFromObj(vm);
-    priv = vm->privateData;
     if (priv->agent)
         qemuAgentNotifyEvent(priv->agent, QEMU_AGENT_EVENT_RESET);
 
     if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
         VIR_WARN("Failed to save status on vm %s", vm->def->name);
 
+    if (callOnReboot &&
+        guest_initiated == VIR_TRISTATE_BOOL_YES &&
+        vm->def->onReboot == VIR_DOMAIN_LIFECYCLE_DESTROY)
+        qemuProcessShutdownOrReboot(driver, vm);
+
     virObjectUnlock(vm);
-
     qemuDomainEventQueue(driver, event);
-
     virObjectUnref(cfg);
     return 0;
 }
@@ -555,6 +579,7 @@ qemuProcessFakeReboot(void *opaque)
         goto endjob;
     }
     priv->gotShutdown = false;
+    priv->gotReset = false;
     event = virDomainEventLifecycleNewFromObj(vm,
                                      VIR_DOMAIN_EVENT_RESUMED,
                                      VIR_DOMAIN_EVENT_RESUMED_UNPAUSED);
@@ -5320,6 +5345,7 @@ qemuProcessPrepareDomain(virConnectPtr conn,
     priv->monError = false;
     priv->monStart = 0;
     priv->gotShutdown = false;
+    priv->gotReset = false;
 
     VIR_DEBUG("Updating guest CPU definition");
     if (qemuProcessUpdateGuestCPU(vm->def, priv->qemuCaps, caps, flags) < 0)
-- 
2.13.0




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