pv-qemu 10/10: Make xenconsoled ignore doms with qemu-dm

This patch writes a field /local/vm/DOMID/console/type taking the
value 'ioemu' or 'xenconsoled'. If xenconsoled sees a type that is
not its own, then it skips handling of that guest. The qemu-dm
process doesn't need to read this field since it will only attach
to the console if given the -serial pty arg which XenD already
ensures matches this xenstore field.

The overall behaviour is that if a paravirt guest has a qemu-dm
process running then that handles the console, otherwise the
xenconsoled handles it. The former is more functional, with the
exception of not currently supporting persistent logging to a
file at the same time as exposing a PTY.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

tools/python/xen/xend/XendDomainInfo.py

@@ -916,8 +916,15 @@ class XendDomainInfo:
                 else:
                     to_store[n] = str(v)
 
+        # Figure out if we need to tell xenconsoled to ignore this guest's
+        # console - device model will handle console if it is running
+        constype = "ioemu"
+        if 'device_model' not in self.info['platform']:
+            constype = "xenconsoled"
+
         f('console/port',     self.console_port)
         f('console/ring-ref', self.console_mfn)
+        f('console/type',     constype)
         f('store/port',       self.store_port)
         f('store/ring-ref',   self.store_mfn)