Re: [Xen-devel] [PATCH v2] x86/vlapic: Don't reset APIC ID when handling INIT signal

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.04.17 at 21:33, <chao.gao@xxxxxxxxx> wrote:
> On Wed, Apr 19, 2017 at 03:41:41PM +0800, Chao Gao wrote:
>>>> -    vlapic->hw.apic_base_msr = (MSR_IA32_APICBASE_ENABLE |
>>>> -                                APIC_DEFAULT_PHYS_BASE);
>>>> +    vlapic->hw.apic_base_msr |= APIC_DEFAULT_PHYS_BASE;
>>>
>>>Perhaps better move this ahead of the call to vlapic_reset() then
>>>too.
>>>
>>>Remains the question (not answered by the SDM afaics): What
>>>happens to the base address during reset?
>>
>>Actually, I don't know and that's also why I don't touch apic_base_msr in the
>>first verson. Will try to get a confirmation from hardware guys.
> 
> According to the description about APIC base address in 
> "ADVANCED PROGRAMMABLE INTERRUPT CONTROLLER (APIC) ->
> "LOCAL APIC" -> "Local APIC Status and Location", the APIC base
> address is set to 0xFEE00000H as a result of reset or power-up.

Ah, yes - not very helpful for the different pieces of reset state to
be scattered across the document.

Jan


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