libvirt.tests: Add testcase for ethernet iommu group.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
libvirt.tests: Add vfio testcases for fibre device.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
libvirt.tests: Add more testcases for VFIO and bugfix.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
Add ttcp test for network.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
libvirt.tests: a bunch of amendments to vfio tests.

* Support to provide gateway for network device.
* Change the way to remove boot elements in os.
  Because when there is not boot_order for vm, libvirt
  will add boot element to 'hd' automatically.
  We have to remove it after adding boot_order for devices.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
Merge pull request #342 from yumingfei/vfio_test

libvirt.tests: Add testcase for ethernet iommu group.