Add functions to get disk slots and disk type in xml.
virttest.virsh: add blkiotune command wrapper

Signed-off-by: Alex Jia <ajia@redhat.com>
virttest.utils_misc: add functions for getting major and minor numbers of the device

Signed-off-by: Alex Jia <ajia@redhat.com>
virttest.libvirt_xml.vm_xml: parse block I/O elements from XML

Signed-off-by: Alex Jia <ajia@redhat.com>
Modify get_disk_slots function to get_virtio_disk_slots.
get_image_info: Adjustments for tp-libvirt

Don't use the 'normalize_data_size()' method for the returned 'vsize'.
Use the 'bytes' value within the parentheses since it's the real value
that qemu-img finds/determines from the meta data.

Additionally rather than having two modules do the exact same thing,
have the utils_test/__init__.py call the utils_misc/get_image_info()

Signed-off-by: John Ferlan <jferlan@redhat.com>
Merge pull request #1661 from jferlan/get_image_info

get_image_info: Use 'bytes' value from qemu-img instead of normalize_data_size value
Merge pull request #1667 from rbian/virtual-disks

Virtual disks cases.
Merge pull request #1678 from chuanchang/blkiotune

Add helper functions for testing virsh blkiotune command