Description of problem:

When a shutdown is requested, virt-launcher asks libvirt to do a shutdown via ACPI (power button).

func (l *LibvirtDomainManager) SignalShutdownVMI(vmi *v1.VirtualMachineInstance) error {
...
if domState == libvirt.DOMAIN_RUNNING || domState == libvirt.DOMAIN_PAUSED
{ err = dom.ShutdownFlags(libvirt.DOMAIN_SHUTDOWN_ACPI_POWER_BTN) <-----
... }

This is not an optimal graceful shutdown method, the Guest OS configuration may ignore this, ask confirmation etc.

Guest Agent is the prefered method over ACPI, its even in our RHEL9 documentation: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html-single/configuring_and_managing_virtualization/index#virtualization-features-that-require-qemu-guest-agent_enabling-qemu-guest-agent-features-on-your-virtual-machines

Other products such as RHV (and vSphere) will also try to shutdown first via Guest Agent if its connected, and only fallback to ACPI if that is not available.

This reduces the chances of VMs getting stuck on shutdown and also possibly killed by timeout, which is not ideal.

Version-Release number of selected component (if applicable):

4.15.2

How reproducible:

Always

Steps to Reproduce:

1. Get a Windows VM and set some custom power policy so that the power button is ignored, or asks the user to confirm etc https://www.bringingyourtechtolife.com/post/changing-what-your-power-button-does-on-laptop
2. Send the graceful shutdown request from console

Actual results:

Guest doesn't shutdown gracefully

Expected results:

Guest shutdown gracefully