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Date: Mon, 04 May 2009 13:01:55 +0300
From: Avi Kivity <avi@redhat.com>
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Subject: [Qemu-devel] Re: [PATCH 8/8] kvm: Rework VCPU reset
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, qemu-devel@nongnu.org

Jan Kiszka wrote:
> Avi Kivity wrote:
>   
>> Jan Kiszka wrote:
>>     
>>> Avi Kivity wrote:
>>>  
>>>       
>>>> Jan Kiszka wrote:
>>>>    
>>>>         
>>>>> Use standard callback with highest order to synchronize VCPU on reset
>>>>> after all device callbacks were execute. This allows to remove the
>>>>> special kvm hook in qemu_system_reset.
>>>>>         
>>>>>           
>>>> Is this needed for the lapic reset callback?
>>>>
>>>> If so, we can express the dependency explicitly rather than with a
>>>> priority, by having cpu reset notifiers invoked when the cpu is
>>>> reset. In the case of the lapic, I don't think we need an abstract
>>>> mechanism;
>>>> the lapic is part of the cpu, not some random device.
>>>>
>>>> Maybe we should even save/load it as part of the cpu.
>>>>
>>>>     
>>>>         
>>> QEMU is not only providing the LAPIC, but also covering the old
>>> dedicated version. That makes at least HW instantiating a bit more
>>> complex.
>>>
>>>   
>>>       
>> What do you mean by 'old dedicated version'?
>>     
>
> Separate chip, not part of the CPU. Some 486 system used to have this IIRC.
>
>   

Yes, you're right.

Maybe we can have a vcpu reset callback for the lapic.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.