From: Peter Krempa <pkrempa@redhat.com>
Date: Fri, 24 Apr 2015 14:48:26 +0000 (+0200)
Subject: qemu: Connect to guest agent after channel hotplug
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=a03e2d3a9927eb2d207dc83e3e45c2e403732330;p=people%2Fliuw%2Flibxenctrl-split%2Flibvirt.git

qemu: Connect to guest agent after channel hotplug

If a user hot-attaches the guest agent channel libvirt would ignore it
until the restart of libvirtd or shutdown/destroy and start of the VM
itself.

This patch adds code that opens or closes the guest agent connection
according to the state of the guest agent channel according to
connect/disconnect events.

To allow opening the channel from the event handler qemuConnectAgent
needed to be exported.
---

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 6b1644190..70bf7aa1d 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4468,6 +4468,8 @@ processSerialChangedEvent(virQEMUDriverPtr driver,
     virDomainChrDeviceState newstate;
     virObjectEventPtr event = NULL;
     virDomainDeviceDef dev;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    int rc;
 
     if (connected)
         newstate = VIR_DOMAIN_CHR_DEVICE_STATE_CONNECTED;
@@ -4494,10 +4496,35 @@ processSerialChangedEvent(virQEMUDriverPtr driver,
         dev.data.chr->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO)
         goto endjob;
 
-    if (STREQ_NULLABLE(dev.data.chr->target.name, "org.qemu.guest_agent.0") &&
-        (event = virDomainEventAgentLifecycleNewFromObj(vm, newstate,
-                                                        VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_CHANNEL)))
-        qemuDomainEventQueue(driver, event);
+    if (STREQ_NULLABLE(dev.data.chr->target.name, "org.qemu.guest_agent.0")) {
+        switch (newstate) {
+        case VIR_DOMAIN_CHR_DEVICE_STATE_CONNECTED:
+            if (!priv->agent) {
+                if ((rc = qemuConnectAgent(driver, vm)) == -2)
+                    goto endjob;
+
+                if (rc < 0)
+                    priv->agentError = true;
+            }
+            break;
+
+        case VIR_DOMAIN_CHR_DEVICE_STATE_DISCONNECTED:
+            if (priv->agent) {
+                qemuAgentClose(priv->agent);
+                priv->agent = NULL;
+                priv->agentError = false;
+            }
+            break;
+
+        case VIR_DOMAIN_CHR_DEVICE_STATE_DEFAULT:
+        case VIR_DOMAIN_CHR_DEVICE_STATE_LAST:
+            break;
+        };
+
+        if ((event = virDomainEventAgentLifecycleNewFromObj(vm, newstate,
+                                                            VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_CHANNEL)))
+            qemuDomainEventQueue(driver, event);
+    }
 
     dev.data.chr->state = newstate;
 
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 75ccb66ff..7eeee4725 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -202,7 +202,7 @@ static qemuAgentCallbacks agentCallbacks = {
 };
 
 
-static int
+int
 qemuConnectAgent(virQEMUDriverPtr driver, virDomainObjPtr vm)
 {
     qemuDomainObjPrivatePtr priv = vm->privateData;
diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
index c67b0cb67..d40f68d3a 100644
--- a/src/qemu/qemu_process.h
+++ b/src/qemu/qemu_process.h
@@ -113,4 +113,6 @@ int qemuProcessSPICEAllocatePorts(virQEMUDriverPtr driver,
 virDomainDiskDefPtr qemuProcessFindDomainDiskByAlias(virDomainObjPtr vm,
                                                      const char *alias);
 
+int qemuConnectAgent(virQEMUDriverPtr driver, virDomainObjPtr vm);
+
 #endif /* __QEMU_PROCESS_H__ */