Otherwise it would point at the same object and for example changing
vm.services[] in one VM will change that also for another. That link
will be severed after reloading the VMs from qubes.xml, but at least in
case of DispVM startup its too late - vm.service['qubes-dvm'] is set for
the DispVM template even during normal startup, not savefile preparation.
This allows to specify tight network isolation for a VM, and finally
close one remaining way for leaking traffic around TorVM. Now when VM is
connected to for example TorVM, its DispVMs will be also connected
there.
The new property can be set to:
- default (uses_default_dispvm_netvm=True) - use the same NetVM/ProxyVM as the
calling VM itself - including none it that's the case
- None - DispVMs will be network-isolated
- some NetVM/ProxyVM - will be used, even if calling VM is network-isolated
Closesqubesos/qubes-issues#862
Debian do not use hostname in gnome-terminal window title by default, so
the test failed there, even when DispVM was started correctly.
Additionally we can't rely on gnome-terminal --title, as it isn't
working on Debian 8...
Apparently it is much faster. Especially during savefile preparation -
tar reads the whole file, while bsdtar gets file map and reads only used
regions.
Define it only when really needed:
- during VM creation - to generate UUID
- just before VM startup
As a consequence we must handle possible exception when accessing
vm.libvirt_domain. It would be a good idea to make this field private in
the future. It isn't possible for now because block_* are external for
QubesVm class.
This hopefully fixes race condition when Qubes Manager tries to access
libvirt_domain (using some QubesVm.*) at the same time as other tool is
removing the domain. Additionally if Qubes Manage would loose that race, it could
define the domain again leaving some unused libvirt domain (blocking
that domain name for future use).
Provide vm.refresh(), which will force to reconnect do QubesDB daemon,
and also get new libvirt object (including new ID, if any). Use this
method whenever QubesDB call returns DisconnectedError exception. Also
raise that exception when someone is trying to talk to not running
QubesDB - instead of returning None.
Libvirt will replace domain XML when trying to define the new one with
the same name and UUID - this is exactly what we need. This fixes race
condition with other processes (especially Qubes Manager), which can try
to access that libvirt domain object at the same time.
It have nothing to do with xenstore, so change the name to not mislead.
Also get rid of unused "xid" parameter - we should use XID as little as
possible, because it is not a simple task to keep it current.
