qemu-ga: Make QGA VSS provider service run only when needed

Currently the service runs in background on boot even though it is not
needed and once it is running it never stops. The service needs to be
running only during freeze operation and it should be stopped after
executing thaw.

Signed-off-by: Sameeh Jubran <sameeh@daynix.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

qga/vss-win32/install.cpp

@@ -14,7 +14,7 @@
 
 #include "vss-common.h"
 #include <inc/win2003/vscoordint.h>
-#include <comadmin.h>
+#include "install.h"
 #include <wbemidl.h>
 #include <comdef.h>
 #include <comutil.h>
@@ -276,7 +276,7 @@ STDAPI COMRegister(void)
 
     chk(pCatalog->CreateServiceForApplication(
             _bstr_t(QGA_PROVIDER_LNAME), _bstr_t(QGA_PROVIDER_LNAME),
-            _bstr_t(L"SERVICE_AUTO_START"), _bstr_t(L"SERVICE_ERROR_NORMAL"),
+            _bstr_t(L"SERVICE_DEMAND_START"), _bstr_t(L"SERVICE_ERROR_NORMAL"),
             _bstr_t(L""), _bstr_t(L".\\localsystem"), _bstr_t(L""), FALSE));
     chk(pCatalog->InstallComponent(_bstr_t(QGA_PROVIDER_LNAME),
                                    _bstr_t(dllPath), _bstr_t(tlbPath),
@@ -461,3 +461,27 @@ namespace _com_util
         return bstr;
     }
 }
+
+/* Stop QGA VSS provider service from COM+ Application Admin Catalog */
+
+STDAPI StopService(void)
+{
+    HRESULT hr;
+    COMInitializer initializer;
+    COMPointer<IUnknown> pUnknown;
+    COMPointer<ICOMAdminCatalog2> pCatalog;
+
+    int count = 0;
+
+    chk(QGAProviderFind(QGAProviderCount, (void *)&count));
+    if (count) {
+        chk(CoCreateInstance(CLSID_COMAdminCatalog, NULL, CLSCTX_INPROC_SERVER,
+            IID_IUnknown, (void **)pUnknown.replace()));
+        chk(pUnknown->QueryInterface(IID_ICOMAdminCatalog2,
+            (void **)pCatalog.replace()));
+        chk(pCatalog->ShutdownApplication(_bstr_t(QGA_PROVIDER_LNAME)));
+    }
+
+out:
+    return hr;
+}

qga/vss-win32/install.h

@@ -0,0 +1,20 @@
+/*
+ * QEMU Guest Agent VSS requester declarations
+ *
+ * Copyright Hitachi Data Systems Corp. 2013
+ *
+ * Authors:
+ *  Tomoki Sekiyama   <tomoki.sekiyama@hds.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef INSTALL_H
+#define INSTALL_H
+
+#include <comadmin.h>
+
+STDAPI StopService(void);
+
+#endif

qga/vss-win32/requester.cpp

@@ -13,6 +13,7 @@
 #include "qemu/osdep.h"
 #include "vss-common.h"
 #include "requester.h"
+#include "install.h"
 #include <inc/win2003/vswriter.h>
 #include <inc/win2003/vsbackup.h>
 
@@ -501,4 +502,5 @@ void requester_thaw(int *num_vols, ErrorSet *errset)
     requester_cleanup();
 
     CoUninitialize();
+    StopService();
 }