[vfio-users] Preventing host from going into sleep

[Nicolas Roy-Renaud]

The thing is that I want my computer to be able to go to sleep at the 
press of a button *unless* I'm running a VM. Systemd-inhibit does 
exactly what a want here, complete with a warning and an override 
prompt, but I haven't managed to get it to communicate properly with the 
system dbus when it's being launched by libvirt.

- Nicolas


On 2016-06-22 12:42, Laszlo Ersek wrote:
> On 06/22/16 07:01, Nicolas Roy-Renaud wrote:
>> I've had my fair share of lockups because I forgot to turn off my VM
>> before putting my host to sleep, and I've started looking into some sort
>> of lock to prevent that kind of mistake. Normally, I'd use something
>> like `systemd-inhibit
>> <https://www.freedesktop.org/software/systemd/man/systemd-inhibit.html>`
>> to do that, except the calls libvirt makes to its hook scripts are
>> self-contained while sysd-inhibit is completely synchroneous (you use it
>> just like `time`). I've looked into using the underlying dbus calls
>> instead, and it appears that since Inhibit()
>> <https://www.freedesktop.org/wiki/Software/systemd/inhibit/> returns a
>> file descriptor which expires as soon as its owner is closed, I can't
>> just lock it before the VM starts and close it when it stops.
>>
>> By the looks of it, I can't write a wrapper script for qemu-system
>> either since libvirt doesn't launch it with the same capabilities as a
>> regular user, and the dbus calls coming from sysd-inhibit fail.
>>
>> I can't seem to find a simple solution to that issue, which is a pretty
>> big deal considering it's not something that libvirt supports on its own
>> (unless I've missed something). What would you all reccomend?
> man logind.conf
>
> Locate all settings / actions related to S3 suspend, and disable them in
> your logind.conf (possible pathnames are listed in the manual page).
>
> Personally I hate when my laptop suspends as soon as I close the lid (->
> another sign of the desktop mentality: "if I'm not looking, nothing can
> be happening!"). I disabled it with the following setting in
> "/etc/systemd/logind.conf":
>
> HandleLidSwitch=ignore
>
> I trust if you set some more actions to "ignore", they'll do what you want.
>
> HTH
> Laszlo