[libvirt] [PATCH 5/7] qemu: snapshot: Add helper to generate lifecycle events

[Peter Krempa]

Add helper that will generate domain lifecycle events regarding to
snapshot revert operations and use it in a demonstration case in the
code.

The helper will be later used in internal snaphsot revert refactor more
widely.
---
 src/qemu/qemu_driver.c | 142 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 136 insertions(+), 6 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 2d58b53..e794e02 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -13907,6 +13907,139 @@ qemuDomainSnapshotRevertInactive(virQEMUDriverPtr driver,
     return ret > 0 ? -1 : ret;
 }

+
+static int
+qemuDomainSnapshotEmitLifecycleEvent(virQEMUDriverPtr driver,
+                                     virDomainObjPtr vm,
+                                     virDomainState oldState,
+                                     virDomainState newState)
+{
+    int reason = 0;
+    int type = -1;
+    virObjectEventPtr event = NULL;
+
+    switch (newState) {
+    case VIR_DOMAIN_RUNNING:
+        switch (oldState) {
+        case VIR_DOMAIN_NOSTATE:
+        case VIR_DOMAIN_SHUTOFF:
+        case VIR_DOMAIN_CRASHED:
+        case VIR_DOMAIN_SHUTDOWN:
+            type = VIR_DOMAIN_EVENT_STARTED;
+            reason = VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT;
+            break;
+
+        case VIR_DOMAIN_PMSUSPENDED:
+        case VIR_DOMAIN_PAUSED:
+            type = VIR_DOMAIN_EVENT_RESUMED;
+            reason = VIR_DOMAIN_EVENT_RESUMED_FROM_SNAPSHOT;
+            break;
+
+        case VIR_DOMAIN_LAST:
+        case VIR_DOMAIN_RUNNING:
+        case VIR_DOMAIN_BLOCKED:
+            /* no event */
+            break;
+        }
+        break;
+
+    case VIR_DOMAIN_PAUSED:
+        switch (oldState) {
+        case VIR_DOMAIN_NOSTATE:
+        case VIR_DOMAIN_SHUTOFF:
+        case VIR_DOMAIN_CRASHED:
+            /* the machine was started here, so we need an additional event */
+            event = virDomainEventLifecycleNewFromObj(vm,
+                                                      VIR_DOMAIN_EVENT_STARTED,
+                                                      VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT);
+            if (!event)
+                goto cleanup;
+            qemuDomainEventQueue(driver, event);
+            /* fallthrough! */
+        case VIR_DOMAIN_PMSUSPENDED:
+        case VIR_DOMAIN_RUNNING:
+        case VIR_DOMAIN_SHUTDOWN:
+            type = VIR_DOMAIN_EVENT_SUSPENDED;
+            reason = VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT;
+            break;
+
+        case VIR_DOMAIN_PAUSED:
+        case VIR_DOMAIN_LAST:
+        case VIR_DOMAIN_BLOCKED:
+            /* no event */
+            break;
+        }
+        break;
+
+    case VIR_DOMAIN_SHUTOFF:
+        switch (oldState) {
+        case VIR_DOMAIN_NOSTATE:
+        case VIR_DOMAIN_BLOCKED:
+        case VIR_DOMAIN_SHUTDOWN:
+        case VIR_DOMAIN_PAUSED:
+        case VIR_DOMAIN_RUNNING:
+        case VIR_DOMAIN_PMSUSPENDED:
+            type = VIR_DOMAIN_EVENT_STOPPED;
+            reason = VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT;
+            break;
+
+        case VIR_DOMAIN_SHUTOFF:
+        case VIR_DOMAIN_CRASHED:
+        case VIR_DOMAIN_LAST:
+            /* no event */
+            break;
+        }
+        break;
+
+    case VIR_DOMAIN_PMSUSPENDED:
+        switch (oldState) {
+        case VIR_DOMAIN_NOSTATE:
+        case VIR_DOMAIN_SHUTOFF:
+        case VIR_DOMAIN_CRASHED:
+            /* the machine was started here, so we need an additional event */
+            event = virDomainEventLifecycleNewFromObj(vm,
+                                                      VIR_DOMAIN_EVENT_STARTED,
+                                                      VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT);
+            if (!event)
+                goto cleanup;
+            qemuDomainEventQueue(driver, event);
+            /* fallthrough! */
+        case VIR_DOMAIN_RUNNING:
+        case VIR_DOMAIN_SHUTDOWN:
+        case VIR_DOMAIN_PAUSED:
+            type = VIR_DOMAIN_EVENT_PMSUSPENDED;
+            reason = VIR_DOMAIN_EVENT_PMSUSPENDED_FROM_SNAPSHOT;
+            break;
+
+        case VIR_DOMAIN_LAST:
+        case VIR_DOMAIN_BLOCKED:
+        case VIR_DOMAIN_PMSUSPENDED:
+            /* no event */
+            break;
+        }
+        break;
+
+    case VIR_DOMAIN_NOSTATE:
+    case VIR_DOMAIN_BLOCKED:
+    case VIR_DOMAIN_SHUTDOWN:
+    case VIR_DOMAIN_CRASHED:
+    case VIR_DOMAIN_LAST:
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Suspicious domain state '%d' after snapshot"),
+                       newState);
+        return -1;
+    }
+
+   if (!(event = virDomainEventLifecycleNewFromObj(vm, type, reason)))
+       goto cleanup;
+
+    qemuDomainEventQueue(driver, event);
+    return 0;
+
+ cleanup:
+    return -1;
+}
+
 static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                                       unsigned int flags)
 {
@@ -14051,12 +14184,9 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                 qemuProcessStop(driver, vm,
                                 VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT, 0);
                 virDomainAuditStop(vm, "from-snapshot");
-                detail = VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT;
-                event = virDomainEventLifecycleNewFromObj(vm,
-                                                 VIR_DOMAIN_EVENT_STOPPED,
-                                                 detail);
-                if (event)
-                    qemuDomainEventQueue(driver, event);
+                qemuDomainSnapshotEmitLifecycleEvent(driver, vm,
+                                                     vm->state.state,
+                                                     VIR_DOMAIN_SHUTOFF);
                 goto load;
             }

-- 
2.0.0