From 6ba861ae361168337828430f85fb8c6b6b5b7c7d Mon Sep 17 00:00:00 2001
From: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Date: Wed, 16 Nov 2016 16:43:03 +0300
Subject: [PATCH] qemu: agent: cleanup agent error flag correctly

Sometimes after domain restart agent is unavailabe even
if it is up and running in guest. Diagnostic message is
"QEMU guest agent is not available due to an error"
that is 'priv->agentError' is set. Investiagion shows that
'priv->agent' is not NULL, so error flag is set probably
during domain shutdown process and not cleaned up eventually.

The patch is quite simple - just clean up error flag unconditionally
upon domain stop.

Other hunks address other cases when error flag is not cleaned up.

1. processSerialChangedEvent. We need to clean error flag
unconditionally here too. For example if upon first 'connected' event we
fail to connect and set error flag and then connect on second
'connected' event then error flag will remain set erroneously
and make agent unavailable.

2. qemuProcessHandleAgentEOF. If error flag is set and we get
EOF we need to change state (and diagnostic) from 'error' to
'not connected'.
---
 src/qemu/qemu_driver.c  | 2 +-
 src/qemu/qemu_process.c | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 1ecb243b8a..ab030fe4f6 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4467,8 +4467,8 @@ processSerialChangedEvent(virQEMUDriverPtr driver,
             if (priv->agent) {
                 qemuAgentClose(priv->agent);
                 priv->agent = NULL;
-                priv->agentError = false;
             }
+            priv->agentError = false;
         }
 
         event = virDomainEventAgentLifecycleNewFromObj(vm, newstate,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index d3a2cbd92a..cb9eb22982 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -151,6 +151,7 @@ qemuProcessHandleAgentEOF(qemuAgentPtr agent,
 
     qemuAgentClose(agent);
     priv->agent = NULL;
+    priv->agentError = false;
 
     virObjectUnlock(vm);
     return;
@@ -5995,8 +5996,8 @@ void qemuProcessStop(virQEMUDriverPtr driver,
     if (priv->agent) {
         qemuAgentClose(priv->agent);
         priv->agent = NULL;
-        priv->agentError = false;
     }
+    priv->agentError = false;
 
     if (priv->mon) {
         qemuMonitorClose(priv->mon);