You should enable power saving (auto suspend) for virutal machine!

[ChipZhang]

I am running LinuxMint in KVM virtual machine. I have the need to put VM in sleep/suspend mode if no activity.
It works pretty fine for KDE desktop in the VM. However, in Cinnamon/MATE desktop, it never auto suspends. If I click the suspend button in the UI, or run systemctl suspend manually, it actually works.

After spending one whole day to debug this problem, I noticed this code:

cinnamon-settings-daemon/plugins/power/csd-power-manager.c

Lines 3011 to 3015 in 789b2ee

	if (manager->priv->is_virtual_machine) {
	g_debug ("ignoring state transition to %s as virtual machine",
	idle_mode_to_string (mode));
	return;
	}

You just force disable auto suspend for all VMs. This is very stupid, as sometimes someone may really need auto suspend. It is the end user rather than you developers that is responsible to decide how to save the power.

You should at least provide an option to enable this feature for VMs. Or you should note the user about this point in the settings UI. Adding some weird "feature" without notifying the end user is really bad! It wasted everyone's time!

[leigh123linux]

We didn't add it, it was inherited from gnome.
They changed it a bit since we forked from them.

GNOME/gnome-settings-daemon@c07ea84

I'm -1 to enabling this for VM default behaviour.

[ChipZhang]

Thanks for reply. Do you have any plan to fix this issue?

[ChipZhang]

If you do not enable auto suspend for VM by default, then you should provide an option to force enable this for VM.

Let the user decide how to save power, rather than you developers.