Open Stack

Hi, I'd like you to take a look at this patch for potential
documentation impact.
https://review.openstack.org/10273

Log:
commit eb074328041b5f8b4f5a109794c54a9bd4e245ed
Author: Daniel P. Berrange <berrange at redhat.com>
Date:   Wed Jul 25 13:32:28 2012 +0100

    Define cross-driver standardized vm_mode values
    
    Currently the XenAPI driver allows for a 'vm_mode' parameter to
    be set against an instance to determine whether it is launched
    a paravirt or fullvirt domain. This allows the values 'pv', 'hv'
    and 'hvm'.
    
    The libvirt driver also needs to be extended to allow a 'vm_mode'
    parameter, and to facilitate deployment of heterogeneous Nova
    compute farms, it is desirable to have standardization of the
    VM mode values across all drivers.
    
    To address this, the nova.compute.vm_mode module is introduced
    which defines a set of constants. The constants provide four
    possible vm modes:
    
     - vm_mode.XEN = 'xen' - for Xen 3.0 paravirt ABI
     - vm_mode.HVM = 'hvm' - for native ABI
     - vm_mode.UML = 'uml' - for User Mode Linux paravirt ABI
     - vm_mode.EXE = 'exe' - for container virt executable ABI
    
    The existing 'pv' value from XenAPI is deprecated, because it
    is ambiguous - both Xen and UML are paravirt, and other
    paravirt hypervisor ABIs also exist
    
    The existing 'hv' value is also deprecated since it duplicates
    the other existing 'hvm' value.
    
    The 'vm_mode.get_from_instance' method will extract the
    vm_mode value for an instance. It normalizes the value to
    all lower case, translates 'hv' and 'pv' into the new
    values for back compat, and validates that the value
    matches one of the defined constants
    
    The XenAPI and libvirt drivers are then updated to use the
    nova.compute.vm_mode constants instead of bare strings.
    The test_xenapi.py test case is updated to set 'vm_mode'
    to exercise the new codepaths. A new test_vmmode.py
    case is also written to fully exercise the logic
    
    NB, previously the libvirt driver would set 'guest.os_type'
    to 'linux' to request Xen paravirt. This is a legacy value,
    with libvirt preferring the string 'xen'. So although the
    new code sets a different value for Xen paravirt os_type,
    the functional result is unchanged.
    
    DocImpact
    blueprint hypervisor-code-consolidation
    Change-Id: I23efc5dc1528b0d8472d752a8a30f55c85310b21
    Signed-off-by: Daniel P. Berrange <berrange at redhat.com>