Re: [Qemu-devel] [PATCH] hw/pci-host: Fix x86 Host Bridges 64bit PCI hole

[Marcel Apfelbaum <marcel@redhat.com>]

On 19/10/2017 16:03, Gerd Hoffmann wrote:
>    Hi,
> 
>>    - commit 39848901818 pc: limit 64 bit hole to 2G by default
>>    shows us QEMU had the 64bit PCI hole, so it is a regression.
> 
> commit message says:
> 
> <quote>
>      It turns out that some 32 bit windows guests crash
>      if 64 bit PCI hole size is >2G.
> </quote>
> 
> Why this suddenly isn't a problem any more?
> 

I suppose it is, so we need a way to turn it "off".

> Also: how about just using the existing pci_hole64_size property?
> 

This is how I started, however Eduardo and (and maybe Michael ?)
where against letting the upper management software to deal with
such a low low level detail. They simply can't take such a decision.
This is why the property you mentioned is not ever linked
in code anywhere! It is simply not implemented and not used.

What about renaming the added compat property
from x-pci-hole64-fix to pci-hole64? Users using 32-bit Windows
guests having the mentioned issue guests will disable it.

Thanks,
Marcel

> cheers,
>    Gerd
>