Early ACPI events prevent subsequent ACPI functionality on xen 4.3 + HVM domU

[Diana Crisan <dcrisan@flexiant.com>]

This is problem 3 of 3 problems we are having with live migration and/or ACPI on Xen-4.3 and Xen-4.2.

Any help would be appreciated.

Detailed description of problem:

We are using Xen-4.3-rc1 with dom0 running Ubuntu Precise and 3.5.0-23-generic kernel, and domU running Ubuntu Precise (12.04) cloud images running 3.2.0-39-virtual. We are using the xl.conf below on qemu-upstream-dm and HVM and two identical sending and receiving machines (hardware and software)

If a dom-U HVM server is started with ACPI enabled, and an ACPI event (such as shutdown or reboot) is sent to domU before the BIOS and/or operating system in the dom-U has initialised ACPI, then all subsequent ACPI events are ignored.

This is replicable every time.

How to replicate:
1. Take a machines running xen-4.3-rc1 version of Xen on Ubuntu Precise with 3.5.0-23-generic kernel.
2. Use the xl.conf below as a configuration file.
3. Create a VM using Ubuntu Precise and 3.5.0-23 generic.
4. Start the VM
5. Immediately (before boot is completed) run 'xl shutdown' or 'xl reboot'. As ACPI is not initialised, this will have no effect.
6. Wait until domU has completed booting.
7. Run 'xl shutdown' or 'xl reboot' again.

Expected results:

At step 7, domU will shutdown or reboot as appropriate

Actual results:

domU does not shutdown or reboot and it is necessary to 'xl des' the domU to stop it.

Notes:

On xen-4.2, a similar thing happens.

--xl.conf--

builder='hvm'
memory = 512
name = "416-vm"
vcpus=1
disk = [ 'tap:qcow2:/root/diana.qcow2,xvda,w' ]
vif = ['mac=00:16:3f:1d:6a:c0, bridge=defaultbr']
sdl=0
opengl=1
vnc=1
vnclisten="0.0.0.0"
vncdisplay=0
vncunused=0
vncpasswd='p'
stdvga=0
serial='pty'