Re: KVM_EXIT_HALT and KVM_CREATE_IRQCHIP

[Avi Kivity <avi@redhat.com>]

On 06/10/2010 01:15 PM, Pekka Enberg wrote:
>
> On 06/10/2010 12:52 PM, Pekka Enberg wrote:
>>> I see there's a KVM_GET_MP_STATE ioctl that can be used to check if
>>> state is KVM_MP_STATE_HALTED but as we never exit to the hypervisor,
>>> how is this supposed to work? Am I missing something obvious here?
>
> On 6/10/10 1:03 PM, Avi Kivity wrote:
>> In general you only rarely want to check the state (example are for
>> debugging and for live migration). It's not a stable value (the guest
>> executing HLT, or a guest interrupt delivered, will change its value).
>> What's your use case?
>
> Well, power off, basically. Specifically, running a small test 
> 'kernel' that exists after it's done its work. I guess the thing I was 
> missing was that hlt is really for other purposes than power off. I 
> guess it's up to the hypervisor to emulate APM or something and stop 
> the hypervisor there?
>

HLT has nothing to do with power off.  Qemu emulates ACPI power 
management, you can either do that or roll your own (for example an I/O 
port that calls exit(0) when the guest accesses it).

-- 
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