Fix generating documentation

doc/index.rst

@@ -17,7 +17,6 @@ manpages and API documentation. For primary user documentation, see
    qubes-vm/index
    qubes-events
    qubes-exc
-   qubes-plugins
    qubes-ext
    qubes-log
    qubes-tools/index

doc/qubes-plugins.rst

@@ -1,8 +0,0 @@
-:py:mod:`qubes.plugins` -- Plugin helpers
-=========================================
-
-.. automodule:: qubes.plugins
-   :members:
-   :show-inheritance:
-
-.. vim: ts=3 sw=3 et

qubes/qmemman/__init__.py

@@ -70,7 +70,10 @@ class SystemState(object):
         # see https://wiki.openstack.org/wiki/XenServer/Overhead
         # we divide total and free physical memory by this to get "assignable" memory
         self.MEM_OVERHEAD_FACTOR = 1.0 / 1.00781
+        try:
             self.ALL_PHYS_MEM = int(self.xc.physinfo()['total_memory']*1024 * self.MEM_OVERHEAD_FACTOR)
+        except xen.lowlevel.xc.Error:
+            self.ALL_PHYS_MEM = 0
 
     def add_domain(self, id):
         self.log.debug('add_domain(id={!r})'.format(id))