Re: [PATCH v4 5/6] i386: Hyper-V VMBus ACPI DSDT entry

[Jon Doron <arilou@gmail.com>]

On 28/05/2020, Jon Doron wrote:
>On 22/05/2020, Igor Mammedow wrote:
>>On Thu, 21 May 2020 18:02:07 +0200
>>Paolo Bonzini <pbonzini@redhat.com> wrote:
>>
>>>On 13/05/20 17:34, Igor Mammedov wrote:
>>>> I'd rather avoid using random IRQ numbers (considering we are
>>>> dealing with black-box here). So if it's really necessary to have
>>>> IRQ described here, I'd suggest to implement them in device model
>>>> so they would be reserved and QEMU would error out in a sane way if
>>>> IRQ conflict is detected.
>>>
>>>We don't generally detect ISA IRQ conflicts though, do we?
>>
>>that I don't know that's why I'm not suggesting how to do it.
>>The point is hard-coding in AML random IRQs is not right thing to do,
>>(especially with the lack of 'any' spec), as minimum AML should pull
>>it from device model and that probably should be configurable and set
>>by board.
>>
>>Other thing is:
>>I haven't looked at VMBus device model in detail, but DSDT part aren't
>>matching device though (device model is not ISA device hence AML part
>>shouldn't be on in ISA scope), where to put it is open question.
>>There were other issues with AML code, I've commented on, so I was
>>waiting on respin with comments addressed.
>>I don't think that this patch is good enough for merging.
>>
>>
>
>But it seems like the current patch does match what's Microsoft HyperV 
>is publishing in it's APCI tables.
>
>I dont think it's correct for us to "fix" Microsoft emulation even if 
>it's wrong, since that's what Windows probably expects to see...
>
>I tried looking where Microsoft uses the ACPI tables to identify the 
>VMBus but without much luck in order to understand how flexible a 
>change would be for the OS to still detect the VMBus device, but in 
>general I think "correcting" something that is emulated 1:1 because 
>there is no spec is the right way.
>

Bah sorry meant to say:
In general correcting some virtual emulated device which is current is 
matching 1:1 is wrong, I think the right way to handle this type of 
things is to copy them 1:1 and not try to "fix" or "correct" them since 
that's what Windows expects.

>>>
>>>Paolo
>>>
>>