Re: [Qemu-devel] [PATCH] spapr: support CPU hotplug

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/27/2013 05:02 PM, Paolo Bonzini wrote:
> Il 27/08/2013 08:37, Alexey Kardashevskiy ha scritto:
>>>> So this is here to make sure we don't accidentally get out of halted state by an interrupt on that vcpu. Could you please somehow make that part obvious? Either by adding a comment or by only explicitly masking DEC and EE and a comment :).
>>>>
>>>>> +    cs->exit_request = 1;
>>>>
>>>> This should probably be qemu_cpu_kick_self().
>>>
>>> Uh, no, I don't think so.  This is there purely to make sure we exit
>>> the inner loop, and actually test cpu_can_run() which will test
>>> halted.  AFAICT qemu_cpu_kick_self() won't do anything similar.
>>
>> rtas_stop_self() eventually returns to kvm_cpu_exec() which calls
>> qemu_cpu_kick_self() and resets cs->exit_request before return so I do not
>> really see the difference in behaviour. And actually both ways CPU stops in
>> exactly the same way. What do I miss?
> 
> What about TCG?

Oh. Right. TCG :(

qemu_cpu_kick_self() crashes the guest and cs->exit_request works fine.

Why? Both should work? What is the expected behavior here? Thanks.


-- 
Alexey