Re: [Qemu-devel] [PULL 11/13] target-i386: forward CPUID cache leaves when -cpu host is used

[Paolo Bonzini]

Il 19/11/2013 15:46, Peter Lieven ha scritto:
>>>
>> Just replace "if (cs->nr_cores > 1)" in the patch I posted, i.e. after
>> the switch.
> This seems to work. What is in bits 0..5 of eax?

It's the kind of cache.  0 means that there is no cache and the returned
data is not valid.  In theory, Intel says you should only check whether
those bits are 0, and stop iterating when they are, but apparently
something is expecting eax=0.

> What about the number of threads in count == 2?

That's a property of the L2 cache.  It's not related to APIC IDs.

> I would still like to have at least an option to disable the passthru
> without recompiling if other issues occur.

I think of "-cpu host" in general as a hit-or-miss option.  I'm not sure
whether it makes sense to have such fine grain.

Paolo