Pull connection handling code out of doTunnelMigrate

Simplify the doTunnelMigrate() method by pulling out the code
which opens/closes the virConnectPtr  object into a parent
method

* qemu/qemu_driver.c: Add doPeer2PeerMigrate which then calls
  doTunnelMigrate with dconn & dom_xml

docs/libvirt-api.xml

@@ -47,6 +47,7 @@
      <exports symbol='VIR_MIGRATE_LIVE' type='enum'/>
      <exports symbol='VIR_DOMAIN_EVENT_STOPPED_DESTROYED' type='enum'/>
      <exports symbol='VIR_DOMAIN_EVENT_DEFINED_ADDED' type='enum'/>
+     <exports symbol='VIR_VCPU_BLOCKED' type='enum'/>
      <exports symbol='VIR_SECRET_USAGE_TYPE_NONE' type='enum'/>
      <exports symbol='VIR_DOMAIN_EVENT_STARTED_MIGRATED' type='enum'/>
      <exports symbol='VIR_STREAM_EVENT_HANGUP' type='enum'/>
@@ -82,7 +83,7 @@
      <exports symbol='VIR_STREAM_EVENT_WRITABLE' type='enum'/>
      <exports symbol='VIR_DOMAIN_SCHED_FIELD_DOUBLE' type='enum'/>
      <exports symbol='VIR_DOMAIN_SCHED_FIELD_LLONG' type='enum'/>
-     <exports symbol='VIR_VCPU_BLOCKED' type='enum'/>
+     <exports symbol='VIR_MIGRATE_TUNNELLED' type='enum'/>
      <exports symbol='VIR_DOMAIN_SCHED_FIELD_BOOLEAN' type='enum'/>
      <exports symbol='VIR_DOMAIN_XML_INACTIVE' type='enum'/>
      <exports symbol='VIR_STORAGE_VOL_BLOCK' type='enum'/>
@@ -718,7 +719,8 @@
     <enum name='VIR_FROM_XML' file='virterror' value='5' type='virErrorDomain' info='Error in the XML code'/>
     <enum name='VIR_MEMORY_PHYSICAL' file='libvirt' value='2' type='virDomainMemoryFlags' info=' addresses are physical addresses'/>
     <enum name='VIR_MEMORY_VIRTUAL' file='libvirt' value='1' type='virDomainMemoryFlags' info='addresses are virtual addresses'/>
-    <enum name='VIR_MIGRATE_LIVE' file='libvirt' value='1' type='virDomainMigrateFlags' info=' live migration'/>
+    <enum name='VIR_MIGRATE_LIVE' file='libvirt' value='1' type='virDomainMigrateFlags' info='live migration'/>
+    <enum name='VIR_MIGRATE_TUNNELLED' file='libvirt' value='2' type='virDomainMigrateFlags' info=' tunnelled migration'/>
     <enum name='VIR_SECRET_USAGE_TYPE_NONE' file='libvirt' value='0' type='virSecretUsageType'/>
     <enum name='VIR_SECRET_USAGE_TYPE_VOLUME' file='libvirt' value='1' type='virSecretUsageType' info=' Expect more owner types later...'/>
     <enum name='VIR_STORAGE_POOL_BUILDING' file='libvirt' value='1' type='virStoragePoolState' info='Initializing pool, not available'/>
@@ -1596,6 +1598,8 @@ host given by dconn (a connection to the destination host).
 
 Flags may be one of more of the following:
   VIR_MIGRATE_LIVE   Attempt a live migration.
+  VIR_MIGRATE_TUNNELLED Attempt to do a migration tunnelled through the
+                        libvirt RPC mechanism
 
 If a hypervisor supports renaming domains during migration,
 then you may set the dname parameter to the new name (otherwise

docs/libvirt-refs.xml

@@ -154,6 +154,7 @@
     <reference name='VIR_MEMORY_PHYSICAL' href='html/libvirt-libvirt.html#VIR_MEMORY_PHYSICAL'/>
     <reference name='VIR_MEMORY_VIRTUAL' href='html/libvirt-libvirt.html#VIR_MEMORY_VIRTUAL'/>
     <reference name='VIR_MIGRATE_LIVE' href='html/libvirt-libvirt.html#VIR_MIGRATE_LIVE'/>
+    <reference name='VIR_MIGRATE_TUNNELLED' href='html/libvirt-libvirt.html#VIR_MIGRATE_TUNNELLED'/>
     <reference name='VIR_NODEINFO_MAXCPUS' href='html/libvirt-libvirt.html#VIR_NODEINFO_MAXCPUS'/>
     <reference name='VIR_SECRET_USAGE_TYPE_NONE' href='html/libvirt-libvirt.html#VIR_SECRET_USAGE_TYPE_NONE'/>
     <reference name='VIR_SECRET_USAGE_TYPE_VOLUME' href='html/libvirt-libvirt.html#VIR_SECRET_USAGE_TYPE_VOLUME'/>
@@ -659,6 +660,7 @@
       <ref name='VIR_MEMORY_PHYSICAL'/>
       <ref name='VIR_MEMORY_VIRTUAL'/>
       <ref name='VIR_MIGRATE_LIVE'/>
+      <ref name='VIR_MIGRATE_TUNNELLED'/>
       <ref name='VIR_NODEINFO_MAXCPUS'/>
       <ref name='VIR_SECRET_USAGE_TYPE_NONE'/>
       <ref name='VIR_SECRET_USAGE_TYPE_VOLUME'/>
@@ -1596,6 +1598,7 @@
       <ref name='VIR_MEMORY_PHYSICAL'/>
       <ref name='VIR_MEMORY_VIRTUAL'/>
       <ref name='VIR_MIGRATE_LIVE'/>
+      <ref name='VIR_MIGRATE_TUNNELLED'/>
       <ref name='VIR_NODEINFO_MAXCPUS'/>
       <ref name='VIR_SECRET_USAGE_TYPE_NONE'/>
       <ref name='VIR_SECRET_USAGE_TYPE_VOLUME'/>
@@ -2654,6 +2657,9 @@
           <ref name='virNetworkGetUUIDString'/>
           <ref name='virSecretGetUUIDString'/>
         </word>
+        <word name='RPC'>
+          <ref name='virDomainMigrate'/>
+        </word>
         <word name='Re-attach'>
           <ref name='virNodeDeviceReAttach'/>
         </word>
@@ -2912,6 +2918,9 @@
         <word name='VIR_MIGRATE_LIVE'>
           <ref name='virDomainMigrate'/>
         </word>
+        <word name='VIR_MIGRATE_TUNNELLED'>
+          <ref name='virDomainMigrate'/>
+        </word>
         <word name='VIR_SECRET_USAGE_TYPE_VOLUME'>
           <ref name='virSecretGetUsageID'/>
         </word>
@@ -5604,6 +5613,9 @@
         <word name='means'>
           <ref name='virDomainPinVcpu'/>
         </word>
+        <word name='mechanism'>
+          <ref name='virDomainMigrate'/>
+        </word>
         <word name='mem'>
           <ref name='_virNodeInfo'/>
         </word>
@@ -7381,6 +7393,9 @@
           <ref name='virStoragePoolRef'/>
           <ref name='virStorageVolRef'/>
         </word>
+        <word name='through'>
+          <ref name='virDomainMigrate'/>
+        </word>
         <word name='time'>
           <ref name='_virDomainInfo'/>
           <ref name='_virVcpuInfo'/>
@@ -7443,6 +7458,9 @@
         <word name='trying'>
           <ref name='virConnectOpen'/>
         </word>
+        <word name='tunnelled'>
+          <ref name='virDomainMigrate'/>
+        </word>
         <word name='turn'>
           <ref name='virConnectOpen'/>
         </word>

src/qemu/qemu_driver.c

@@ -6470,7 +6470,9 @@ cleanup:
 
 
 static int doTunnelMigrate(virDomainPtr dom,
+                           virConnectPtr dconn,
                            virDomainObjPtr vm,
+                           const char *dom_xml,
                            const char *uri,
                            unsigned long flags,
                            const char *dname,
@@ -6480,13 +6482,11 @@ static int doTunnelMigrate(virDomainPtr dom,
     int client_sock, qemu_sock;
     struct sockaddr_un sa_qemu, sa_client;
     socklen_t addrlen;
-    virConnectPtr dconn;
     virDomainPtr ddomain;
     int retval = -1;
     ssize_t bytes;
     char buffer[65536];
     virStreamPtr st;
-    char *dom_xml = NULL;
     char *unixfile = NULL;
     int internalret;
     unsigned int qemuCmdFlags;
@@ -6497,35 +6497,15 @@ static int doTunnelMigrate(virDomainPtr dom,
      * destination side is completely setup before we touch the source
      */
 
-    dconn = virConnectOpen(uri);
-    if (dconn == NULL) {
-        qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
-                         _("Failed to connect to remote libvirt URI %s"), uri);
-        return -1;
-    }
-    if (!VIR_DRV_SUPPORTS_FEATURE(dconn->driver, dconn,
-                                  VIR_DRV_FEATURE_MIGRATION_V2)) {
-        qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED, "%s",
-                         _("Destination libvirt does not support required migration protocol 2"));
-        goto close_dconn;
-    }
-
     st = virStreamNew(dconn, 0);
     if (st == NULL)
         /* virStreamNew only fails on OOM, and it reports the error itself */
-        goto close_dconn;
-
-    dom_xml = virDomainDefFormat(dom->conn, vm->def, VIR_DOMAIN_XML_SECURE);
-    if (!dom_xml) {
-        qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
-                         "%s", _("failed to get domain xml"));
-        goto close_stream;
-    }
+        goto cleanup;
 
     internalret = dconn->driver->domainMigratePrepareTunnel(dconn, st,
                                                             flags, dname,
                                                             resource, dom_xml);
-    VIR_FREE(dom_xml);
+
     if (internalret < 0)
         /* domainMigratePrepareTunnel sets the error for us */
         goto close_stream;
@@ -6666,13 +6646,57 @@ close_stream:
     /* don't call virStreamFree(), because that resets any pending errors */
     virUnrefStream(st);
 
-close_dconn:
+cleanup:
+    return retval;
+}
+
+
+static int doPeer2PeerMigrate(virDomainPtr dom,
+                              virDomainObjPtr vm,
+                              const char *uri,
+                              unsigned long flags,
+                              const char *dname,
+                              unsigned long resource)
+{
+    int ret = -1;
+    virConnectPtr dconn = NULL;
+    char *dom_xml;
+
+    /* the order of operations is important here; we make sure the
+     * destination side is completely setup before we touch the source
+     */
+
+    dconn = virConnectOpen(uri);
+    if (dconn == NULL) {
+        qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
+                         _("Failed to connect to remote libvirt URI %s"), uri);
+        return -1;
+    }
+    if (!VIR_DRV_SUPPORTS_FEATURE(dconn->driver, dconn,
+                                  VIR_DRV_FEATURE_MIGRATION_V2)) {
+        qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED, "%s",
+                         _("Destination libvirt does not support required migration protocol 2"));
+        goto cleanup;
+    }
+
+    dom_xml = virDomainDefFormat(dom->conn, vm->def, VIR_DOMAIN_XML_SECURE);
+    if (!dom_xml) {
+        qemudReportError(dom->conn, dom, NULL, VIR_ERR_OPERATION_FAILED,
+                         "%s", _("failed to get domain xml"));
+        goto cleanup;
+    }
+
+    ret = doTunnelMigrate(dom, dconn, vm, dom_xml, uri, flags, dname, resource);
+
+cleanup:
+    VIR_FREE(dom_xml);
     /* don't call virConnectClose(), because that resets any pending errors */
     virUnrefConnect(dconn);
 
-    return retval;
+    return ret;
 }
 
+
 /* Perform is the second step, and it runs on the source host. */
 static int
 qemudDomainMigratePerform (virDomainPtr dom,
@@ -6720,7 +6744,7 @@ qemudDomainMigratePerform (virDomainPtr dom,
     }
 
     if ((flags & VIR_MIGRATE_TUNNELLED)) {
-        if (doTunnelMigrate(dom, vm, uri, flags, dname, resource) < 0)
+        if (doPeer2PeerMigrate(dom, vm, uri, flags, dname, resource) < 0)
             /* doTunnelMigrate already set the error, so just get out */
             goto cleanup;
     } else {