From 2e28f69d3ea540f29c2634c1726b2bb3d0689ec2 Mon Sep 17 00:00:00 2001
From: Wido den Hollander <wido@widodh.nl>
Date: Wed, 27 Feb 2013 16:11:04 +0100
Subject: [PATCH] CLOUDSTACK-1410: >4.1 agents should be able to communicatie
 with <=4.1 management servers

The recently added overcommit feature breaks compatibility between older management servers
and 4.2 agents.

This patch fixes that by falling back if needed.
---
 .../com/cloud/agent/api/to/VirtualMachineTO.java | 16 ++++++++++++++++
 .../kvm/resource/LibvirtComputingResource.java   | 16 +++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/api/src/com/cloud/agent/api/to/VirtualMachineTO.java b/api/src/com/cloud/agent/api/to/VirtualMachineTO.java
index bdd636e727b..99eac6bf8c1 100644
--- a/api/src/com/cloud/agent/api/to/VirtualMachineTO.java
+++ b/api/src/com/cloud/agent/api/to/VirtualMachineTO.java
@@ -28,8 +28,20 @@ public class VirtualMachineTO {
     private BootloaderType bootloader;
     Type type;
     int cpus;
+
+    /**
+        'speed' is still here since 4.0.X/4.1.X management servers do not support
+         the overcommit feature yet.
+
+         The overcommit feature sends minSpeed and maxSpeed
+
+         So this is here for backwards compatibility with 4.0.X/4.1.X management servers
+         and newer agents.
+    */
+    Integer speed;
     Integer minSpeed;
     Integer maxSpeed;
+
     long minRam;
     long maxRam;
     String hostName;
@@ -103,6 +115,10 @@ public class VirtualMachineTO {
         this.cpus = cpus;
     }
 
+    public Integer getSpeed() {
+        return speed;
+    }
+
     public Integer getMinSpeed() {
         return minSpeed;
     }
diff --git a/plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java b/plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java
index 99b8723c26e..805de408996 100755
--- a/plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java
+++ b/plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java
@@ -2934,7 +2934,21 @@ ServerResource {
         vm.addComp(grd);
 
         CpuTuneDef ctd = new CpuTuneDef();
-        ctd.setShares(vmTO.getCpus() * vmTO.getMinSpeed());
+        /**
+            A 4.0.X/4.1.X management server doesn't send the correct JSON
+            command for getMinSpeed, it only sends a 'speed' field.
+
+            So if getMinSpeed() returns null we fall back to getSpeed().
+
+            This way a >4.1 agent can work communicate a <=4.1 management server
+
+            This change is due to the overcommit feature in 4.2
+        */
+        if (vmTO.getMinSpeed() != null) {
+            ctd.setShares(vmTO.getCpus() * vmTO.getMinSpeed());
+        } else {
+            ctd.setShares(vmTO.getCpus() * vmTO.getSpeed());
+        }
         vm.addComp(ctd);
 
         FeaturesDef features = new FeaturesDef();