xenapi live migration without pools: empty vdi-map will cause VM.migrate_send operation to fail as of XenServer 6.1 RC1

The code in question is:

                try:
                    vdi_map = {}
                    vif_map = {}
                    options = {}
                    self._session.call_xenapi("VM.migrate_send", vm_ref,
                                              migrate_data, True,
                                              vdi_map, vif_map, options)

and Mike's comment was:

  If the vdi_map is left empty, the VM.migrate_send operation will fail as of XenServer 6.0 RC1.

Vish asked Mike to submit this bug and assign it to Renuka

Fix proposed to branch: master
Review: https://review.openstack.org/12580

Reviewed: https://review.openstack.org/12580
Committed: http://github.com/openstack/nova/commit/4c72bfc8856ace121ab389279479c9afc1b5960b
Submitter: Jenkins
Branch: master

commit 4c72bfc8856ace121ab389279479c9afc1b5960b
Author: John Garbutt <email address hidden>
Date: Fri Sep 7 12:17:48 2012 +0100

    xapi: Fix live block migration

    Fixes bug 1040332.

    Xapi VM.migrate_send and VM.assert_can_migrate calls require that
    vdi_map parameter is a (source_vdi_ref -> target_sr_ref) mapping, for block
    live migration to work, as of XenServer 6.0 RC1.

    On the destination side:
    This fix modifies the check_can_live_migrate_destination call, so that the
    value returned contains the "destination_sr_ref" (XenAPI specific data is
    stored under the "migrate_send_data key").

    On the source side:
    check_can_live_migrate_source and live_migrate calls assemble the
    vdi_map by mapping all the local sr contained vdis of the VM to
    destination_sr_ref, and passing this parameter to the VM.migrate_send and
    VM.assert_can_migrate Xapi calls.

    Change-Id: I95f3dca651d2e72fc727646580092a25f558d6ba