[libvirt] [PATCH] qemu: Don't fail to shutdown domains with unresponsive agent

[Michal Privoznik]

Currently, qemuDomainShutdownFlags() chooses the agent method of
shutdown whenever the agent is configured. However, this
assumption is not enough as the guest agent may be unresponsive
at the moment. So unless guest agent method has been explicitly
requested, we should fall back to the ACPI method.
---
 src/qemu/qemu_driver.c | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 435c37c..06b14ae 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -1702,7 +1702,7 @@ static int qemuDomainShutdownFlags(virDomainPtr dom, unsigned int flags) {
     virDomainObjPtr vm;
     int ret = -1;
     qemuDomainObjPrivatePtr priv;
-    bool useAgent = false;
+    bool useAgent = false, agentRequested;
 
     virCheckFlags(VIR_DOMAIN_SHUTDOWN_ACPI_POWER_BTN |
                   VIR_DOMAIN_SHUTDOWN_GUEST_AGENT, -1);
@@ -1719,23 +1719,32 @@ static int qemuDomainShutdownFlags(virDomainPtr dom, unsigned int flags) {
         goto cleanup;
 
     priv = vm->privateData;
+    agentRequested = flags & VIR_DOMAIN_SHUTDOWN_GUEST_AGENT;
 
-    if ((flags & VIR_DOMAIN_SHUTDOWN_GUEST_AGENT) ||
+    if (agentRequested ||
         (!(flags & VIR_DOMAIN_SHUTDOWN_ACPI_POWER_BTN) &&
          priv->agent))
         useAgent = true;
 
     if (useAgent) {
         if (priv->agentError) {
-            virReportError(VIR_ERR_AGENT_UNRESPONSIVE, "%s",
-                           _("QEMU guest agent is not "
-                             "available due to an error"));
-            goto cleanup;
+            if (agentRequested) {
+                virReportError(VIR_ERR_AGENT_UNRESPONSIVE, "%s",
+                               _("QEMU guest agent is not "
+                                 "available due to an error"));
+                goto cleanup;
+            } else {
+                useAgent = false;
+            }
         }
         if (!priv->agent) {
-            virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
-                           _("QEMU guest agent is not configured"));
-            goto cleanup;
+            if (agentRequested) {
+                virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
+                               _("QEMU guest agent is not configured"));
+                goto cleanup;
+            } else {
+                useAgent = false;
+            }
         }
     }
 
@@ -1752,7 +1761,12 @@ static int qemuDomainShutdownFlags(virDomainPtr dom, unsigned int flags) {
         qemuDomainObjEnterAgent(vm);
         ret = qemuAgentShutdown(priv->agent, QEMU_AGENT_SHUTDOWN_POWERDOWN);
         qemuDomainObjExitAgent(vm);
-    } else {
+    }
+
+    /* If we are not enforced to use just an agent, try ACPI
+     * shutdown as well in case agent did not succeed */
+    if (!useAgent ||
+        ((ret < 0) && !agentRequested)) {
         qemuDomainSetFakeReboot(driver, vm, false);
 
         qemuDomainObjEnterMonitor(driver, vm);
-- 
1.8.1.4