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

[George Dunlap <george.dunlap@eu.citrix.com>]

On 22/05/13 12:16, Alex Bligh wrote:
> George,
>
> --On 22 May 2013 11:55:03 +0100 George Dunlap 
> <george.dunlap@eu.citrix.com> wrote:
>
>>> I have tested both cases with Ubuntu.
>>> Sending the trigger is reliable if you wait for boot to fully complete.
>>> However, if I issue it during boot it does not get executed. Any
>>> subsequent triggers do not get executed as well until one is sent when
>>> the vm has fully booted.
>>
>> Right -- so what I hear you saying is, "ACPI commands issued before the
>> OS is paying attention are ignored."  I think that's expected behavior.
>>
>> I can see that "Shut this vm down as soon as possible" is a useful thing
>> to have. The problem at the moment guest OSes can ignore signals sent 
>> too
>> early, it doesn't really seem within the scope of libxl to work around
>> that.
>
> I (now) think xl trigger power is working as well as could be expected.
> xl shutdown has a problem (in that an early use of this
> breaks later use), but we can avoid that by using xl trigger power
> (or rather the libxl equivalent). So we have a workaround for this one.

OK -- this will still be on our list of bugs to track, but as it's 
probably a linux issue, it may take some time to filter back into 
distributions.

> FWIW our workaround actually will be send xl trigger power every
> second until the machine disappears, as there is in general no IP
> connectivity between hypervisor and guest in our environment. (Just
> in case anyone is reading the archive and wants a hint).

Ah right -- that makes sense.  Poking it until it shuts off it a bit 
blunt, but should be effective. :-)

  -George