I have actually been going around with support about this issue myself. Maintenance mode does not exist for the VM workload.
How do I stop Failover Clustering long enough to perform some maintenance that involves a reboot without chasing my VM between my clustered hosts?
In failover cluster manager I can select the Virtual Machine and take it offline - this causes my HA VM to be powered down - and also removes it from the Hyper-V manager.
If I select Manage Virtual Machine in failover cluster manager I get directed to the Hyper-V manager.
If I take my Virtual Machine configuration offline - then my VM is shut down but it is not removed from Hyper-V manager.
If I take a snapshot and try to revert, as soon as my VM gets stopped to perform the revert, it gets migrated to another host.
Here is a solution that works ONLY IF you need your VM off: (this works for changing hardware, etc.)
Open the properties of the Virtual Machine resource in Failover clustering.
Set the off-line action to Shut down (this is supposed to stop the VM from failing over and restarting on another host).
Take the resource off-line.
return to Hyper-V and make your changes.
Here is a solution if you want failover clustering to leave your VM alone for a while (so you can reboot it without if failing over):
Open the Virtual Machine properties in Failover Clustering
Select the policies tab
Select "if resource fails, do not restart"
Save that setting.
Return to the Hyper-V Manager and you can open your Virtual Machine Connection console and do things within your VM that may involve a shutdown or reboot to your hearts content.
Just remember that when you want Failover Clustering to be back in charge, you need to return to Failover Clustering and undo what we did above.