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

[Gerd Hoffmann]

  Hi,

> > 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".

Or have machine types behave differently, i.e. give q35 a large 64bit
hole and leave pc as-is.

Devices with that large bars are most likely pci express anyway ...

> 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.

Makes sense.

BTW:  Is it safe to just assume 40 bits physical is going to work?  My
workstation:

model name      : Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz
address sizes   : 39 bits physical, 48 bits virtual

Does this imply ept is limited 39 bits physical too?

cheers,
  Gerd