XenAPI: Cirros images must always boot as PV.

The default for VHD disk-types is PV, which is why booting from a
server works.  However, creating a volume from the image needs to
pass this parameter on to the volume.  Note that
Id673158442fde27e8d468ca412c9bd557a886e6b is also required to fix
bug 1294069

Change-Id: I7ea1d85d6082787ac4551f78300a04bf59074261
Partial-Bug: 1294069

functions

@@ -199,7 +199,21 @@ function upload_image {
     # and should not be decompressed prior to loading
     if [[ "$image_url" =~ '.vhd.tgz' ]]; then
         IMAGE_NAME="${IMAGE_FNAME%.vhd.tgz}"
-        glance --os-auth-token $token --os-image-url http://$GLANCE_HOSTPORT image-create --name "$IMAGE_NAME" --is-public=True --container-format=ovf --disk-format=vhd < "${IMAGE}"
+        FORCE_VM_MODE=""
+        if [[ "$IMAGE_NAME" =~ 'cirros' ]]; then
+            # Cirros VHD image currently only boots in PV mode.
+            # Nova defaults to PV for all VHD images, but
+            # the glance setting is needed for booting
+            # directly from volume.
+            FORCE_VM_MODE="--property vm_mode=xen"
+        fi
+        glance \
+            --os-auth-token $token \
+            --os-image-url http://$GLANCE_HOSTPORT \
+            image-create \
+            --name "$IMAGE_NAME" --is-public=True \
+            --container-format=ovf --disk-format=vhd \
+            $FORCE_VM_MODE < "${IMAGE}"
         return
     fi