From 2dbb51a38d0991120bf3d472c897fa9623ba9e48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Mon, 3 Jul 2017 23:42:39 +0200
Subject: [PATCH] exc/block: fix attaching block device exposed by dom0

Don't set <backenddomain> element in libvirt XML when device is provided
by dom0.
---
 qubes/tests/devices_block.py        | 8 +++-----
 templates/libvirt/devices/block.xml | 2 ++
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/qubes/tests/devices_block.py b/qubes/tests/devices_block.py
index 820753ec..33620060 100644
--- a/qubes/tests/devices_block.py
+++ b/qubes/tests/devices_block.py
@@ -345,7 +345,6 @@ class TC_00_Block(qubes.tests.QubesTestCase):
             '    <driver name="phy" />\n'
             '    <source dev="/dev/sda" />\n'
             '        <target dev="xvdi" />\n'
-            '\n'
             '    <backenddomain name="sys-usb" />\n'
             '</disk>')
         vm.libvirt_domain.attachDevice.assert_called_once_with(device_xml)
@@ -366,7 +365,6 @@ class TC_00_Block(qubes.tests.QubesTestCase):
             '    <driver name="phy" />\n'
             '    <source dev="/dev/sda" />\n'
             '        <target dev="xvdj" />\n'
-            '\n'
             '    <backenddomain name="sys-usb" />\n'
             '</disk>')
         vm.libvirt_domain.attachDevice.assert_called_once_with(device_xml)
@@ -387,7 +385,7 @@ class TC_00_Block(qubes.tests.QubesTestCase):
             '    <driver name="phy" />\n'
             '    <source dev="/dev/sda" />\n'
             '        <target dev="xvdi" />\n'
-            '        <readonly />\n\n'
+            '        <readonly />\n'
             '    <backenddomain name="sys-usb" />\n'
             '</disk>')
         vm.libvirt_domain.attachDevice.assert_called_once_with(device_xml)
@@ -462,7 +460,7 @@ class TC_00_Block(qubes.tests.QubesTestCase):
             '    <driver name="phy" />\n'
             '    <source dev="/dev/sda" />\n'
             '        <target dev="xvdi" />\n'
-            '        <readonly />\n\n'
+            '        <readonly />\n'
             '    <backenddomain name="sys-usb" />\n'
             '</disk>')
         vm.libvirt_domain.attachDevice.assert_called_once_with(device_xml)
@@ -479,7 +477,7 @@ class TC_00_Block(qubes.tests.QubesTestCase):
             '    <driver name="phy" />\n'
             '    <source dev="/dev/sda" />\n'
             '        <target dev="xvdi" />\n'
-            '        <readonly />\n\n'
+            '        <readonly />\n'
             '    <backenddomain name="sys-usb" />\n'
             '</disk>')
         vm = TestVM({}, domain_xml=domain_xml_template.format(device_xml))
diff --git a/templates/libvirt/devices/block.xml b/templates/libvirt/devices/block.xml
index 41327f36..a78dca34 100644
--- a/templates/libvirt/devices/block.xml
+++ b/templates/libvirt/devices/block.xml
@@ -12,5 +12,7 @@
         <readonly />
     {%- endif %}
 
+    {%- if device.backend_domain.name != 'dom0' %}
     <backenddomain name="{{ device.backend_domain.name }}" />
+    {%- endif %}
 </disk>