Launch stdin copy loop in a separate process (multiprocessing.Process)
and terminate it when target process is terminated.
Another idea here was threads, but there is no API to kill a thread
waiting on read().
VMs can have runtime dependencies - for example it isn't possible to
shutdown netvm used by some other running VM(s). Since client-side tools
may not have full knowledge about rules enforcing those dependencies
(for example may not have access to 'netvm' property), implement
best-effort approach:
1. Try to shutdown all requested VMs
2. For those where shutdown request succeed, wait for actual shutdown
3. For others - go back to step 1
And loop until all VMs are shutdown, or all shutdown requests fails.
Allow programming different responses for the same request when called
multiple times. This is useful for example for shutdown tests - first
domain is running, but after issuing shutdown request is is not.
Do not close event loop in utility function - handle it only in main().
For this reason, change appropriate functions to coroutines.
FixesQubesOS/qubes-issues#2865
Don't fail the whole process when "just" appmenus import fails.
But if data import fails, remove the VM
Also update for vm.run_service_for_stdio raising CalledProcessError.
Don't start GUI daemon for given VM twice when qvm-start-gui was started
during VM startup (while waiting for qrexec startup). This is especially
common while running tests.
Report failed qubes.SetMonitorLayout as warning (instead of unhandled
exception).
Clear VM cache on qubesd reconnect.
Fix logging.
qubesd may be restarted during different stages of connection - either
while attempting to connect, or while already listening on events.
Adjust exception list accordingly.
This is especially important for qvm-start-gui - otherwise it crashes on
qubesd restart.
This way we don't need separate admin.vm.Clone call, which is tricky to
handler properly with policy.
A VM may not have access to all the properties and other metadata, so
add ignore_errors argument, for best-effort approach (copy what is
possible). In any case, failure of cloning VM data fails the whole
operation.
When operation fails, VM is removed.
While at it, allow to specify alternative VM class - this allows
morphing one VM into another (for example AppVM -> StandaloneVM).
Adjust qvm-clone tool and tests accordingly.
QubesOS/qubes-issues#2622
Enable 'qrexec' VM feature to wait for qrexec initialization - it is
required to call qubes.PostInstall service. If VM start fails, assume
there is no qrexec and drop that feature.
Since Admin API, qvm-ls takes a long time to complete. Therefore,
Corporate Headquarters commanded that a Enterprise Spinner is to be
implemented and mandated it's use unto us.
We take amusement from its endless gyrations.
Empty parameter value is encoded as b'parameter\0\0', so we can't simply
read the data until b'\0\0', because it isn't necessary event end.
Instead, read event parts separately, according to specification.
