Re: [PATCH 1/2] VMware detection support for x86 and x86-64

[Yan Li <elliot.li.tech@gmail.com>]

On Mon, Sep 08, 2008 at 05:34:07PM -0700, H. Peter Anvin wrote:
>> VMware may change the PCI ID at their will so I prefer checking the
>> DMI since it's easier.
>>
>> So if we ditched the official method we run the risk of some false
>> negatives.  But checking the DMI manufacturer would be good enough.
>>
>
> If we get false negatives that is quite frankly their problem, not ours.  
>  If nothing else, we should be able to look for a host bridge with the  
> VMWare vendor ID -- that should arguably be safer than DMI.

I found that in this situation we can't use PCI info.  My intention to
do this is to fix the false warning from
arch/x86/kernel/cpu/mtrr/main.c (around L695). When booting a VMware
guest we got:
"WARNING: strange, CPU MTRRs all blank?"

For VMware guest this warning is false, just as that for a KVM guest.

This code is from mtrr_trim_uncached_memory(), and used by
setup_arch(), which is used far before PCI is ready.

Therefore I think we can only use DMI here. Any idea?

Thanks!

-- 
Li, Yan

"Everything that is really great and inspiring is created by the
individual who can labor in freedom."
              - Albert Einstein, in Out of My Later Years (1950)