Hi Gerd,
On 20/10/2017 9:55, Gerd Hoffmann wrote:
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 ...
Agreed
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?
The guest will still run with 40 bits physical!
(judging the code anyway, I hope I am wrong)
Then, the stakes are not so big, the Guest kernel will disregard
the 64bit hole since is not CPU addressable and go on.
At least Linux does it, but I think Win10 also can leave with that.
Thanks,
Marcel
cheers,
Gerd
