Default machine type for libvirt does not work with ARM

[Ripal Nathuji]

Today Nova does not pass a specific machine type in the libvirt XML configuration file, resulting in the use of a default machine type. In some cases the operator may want to use a non-default machine type. For example, with ARM by default the machine type is integratorcp, but users need to use the virt model or others such as vexpress-a15 with KVM

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/62775

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/62775
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=8727745562d63149ad16f1ef07cbedcf506076da
Submitter: Jenkins
Branch: master

commit 8727745562d63149ad16f1ef07cbedcf506076da
Author: Ripal Nathuji <email address hidden>
Date: Sun Dec 22 11:42:26 2013 -0600

    Support setting a machine type to enable ARMv7/AArch64 guests to boot

    By default the libvirt driver does not specify a machine type. On ARM systems
    that results in a default type which will fail. This change provides two ways
    to have Nova specify a machine type in the libvirt configuration:

    1) The image can be tagged with the property "hw_machine_type=<type>"
    2) If Nova detects an armv7 or aarch64 processor it will use vexpress-a15 or
       virt machine types respectively (this can be overridden with an image
       property)

    Change-Id: I8aadfcf50e35a1370783ea795f80b29c1a71abff
    Closes-Bug: #1261978
    DocImpact