From a6315091dcb7c01e7083acc3d33cf1aa0cfcc0a5 Mon Sep 17 00:00:00 2001
From: Guido De Rosa <guido.derosa@vemarsas.it>
Date: Wed, 27 Nov 2013 16:23:00 +0100
Subject: [PATCH] qemu: handle unix sockets conditions

(Not-so-)gracefully...
---
 modules/qemu/controller/virtualization/qemu.rb    |  6 ++++++
 .../lib/onboard/virtualization/qemu/instance.rb   | 15 +++++++++++++++
 .../onboard/virtualization/qemu/monitor/qmp.rb    |  3 ++-
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/modules/qemu/controller/virtualization/qemu.rb b/modules/qemu/controller/virtualization/qemu.rb
index 0bbc8af7..46426a3a 100644
--- a/modules/qemu/controller/virtualization/qemu.rb
+++ b/modules/qemu/controller/virtualization/qemu.rb
@@ -6,6 +6,12 @@ class OnBoard
 
   class Controller < Sinatra::Base
 
+    before do
+      if request.path_info =~ /^\/virtualization\/qemu/
+        Virtualization::QEMU.cleanup
+      end
+    end
+
     get '/virtualization/qemu.:format' do
       format(
         :module   => 'qemu',
diff --git a/modules/qemu/lib/onboard/virtualization/qemu/instance.rb b/modules/qemu/lib/onboard/virtualization/qemu/instance.rb
index 6bd8609d..78851ef2 100644
--- a/modules/qemu/lib/onboard/virtualization/qemu/instance.rb
+++ b/modules/qemu/lib/onboard/virtualization/qemu/instance.rb
@@ -273,6 +273,19 @@ def prepare_pci_passthrough
         end
 
         def start(*opts)
+          # WARNING: opts is also a sugar method of this class...
+
+          QEMU.cleanup
+
+          # Circumvent a possible QEMU bug (as of 1.6.1) when a USB device
+          # is passed-through. (assertion failed)
+          unless opts.include? :paused
+            if @config.cmd['opts']['-loadvm']
+              start :paused, *opts
+              drives # a way to wait for QMP/Monitor sockets ready
+              resume
+            end
+          end
 
           # Auto-update from previous versions' configs 
           # which didn't use QMP.
@@ -395,6 +408,8 @@ def drives
               @cache['block_json'] ||= @qmp.execute 'query-block'
               qmp_data = JSON.load @cache['block_json']
               qmp_return = qmp_data['return']
+
+              return {} unless qmp_return
               
               # Compatibility with the old return value of this method
               # (which has been based on "human-redable" monitor...)
diff --git a/modules/qemu/lib/onboard/virtualization/qemu/monitor/qmp.rb b/modules/qemu/lib/onboard/virtualization/qemu/monitor/qmp.rb
index 8bd13919..871f459c 100644
--- a/modules/qemu/lib/onboard/virtualization/qemu/monitor/qmp.rb
+++ b/modules/qemu/lib/onboard/virtualization/qemu/monitor/qmp.rb
@@ -28,7 +28,8 @@ def execute(command, arguments={})
                 sleep pause
                 retry
               else
-                raise
+                LOGGER.error $!
+                return JSON.dump({'error' => {'message' => $!}}) 
               end
             end
           end