tests: Add several net model passthrough tests

Examples of passing unknown strings through <interface>
<model type=X/>

Acked-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>

tests/xlconfigdata/test-net-fakemodel.cfg

@@ -0,0 +1,24 @@
+name = "XenGuest2"
+uuid = "c7a5fdb2-cdaf-9455-926a-d65c16db1809"
+maxmem = 579
+memory = 394
+vcpus = 1
+pae = 1
+acpi = 1
+apic = 1
+viridian = 0
+rtc_timeoffset = 0
+localtime = 0
+on_poweroff = "destroy"
+on_reboot = "restart"
+on_crash = "restart"
+device_model = "/usr/lib/xen/bin/qemu-system-i386"
+sdl = 0
+vnc = 1
+vncunused = 1
+vnclisten = "127.0.0.1"
+vif = [ "mac=00:16:3e:66:92:9c,bridge=xenbr1,script=vif-bridge,model=fakemodel" ]
+parallel = "none"
+serial = "none"
+builder = "hvm"
+boot = "d"

tests/xlconfigdata/test-net-fakemodel.xml

@@ -0,0 +1,40 @@
+<domain type='xen'>
+  <name>XenGuest2</name>
+  <uuid>c7a5fdb2-cdaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>592896</memory>
+  <currentMemory unit='KiB'>403456</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='xenfv'>hvm</type>
+    <loader type='rom'>/usr/lib/xen/boot/hvmloader</loader>
+    <boot dev='cdrom'/>
+  </os>
+  <features>
+    <acpi/>
+    <apic/>
+    <pae/>
+  </features>
+  <clock offset='variable' adjustment='0' basis='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>restart</on_crash>
+  <devices>
+    <emulator>/usr/lib/xen/bin/qemu-system-i386</emulator>
+    <controller type='xenbus' index='0'/>
+    <interface type='bridge'>
+      <mac address='00:16:3e:66:92:9c'/>
+      <source bridge='xenbr1'/>
+      <script path='vif-bridge'/>
+      <model type='fakemodel'/>
+    </interface>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1'>
+      <listen type='address' address='127.0.0.1'/>
+    </graphics>
+    <video>
+      <model type='cirrus' vram='8192' heads='1' primary='yes'/>
+    </video>
+    <memballoon model='xen'/>
+  </devices>
+</domain>