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RE: [Xen-devel] Re: [PATCH] libxc: remove CPUID core information mangling



OK. BTW, the old way seems wrong. The correct implementation should be 
(((regs[2] & 0xf000u) >> 12) + 1) << 12.

-----Original Message-----
From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx] 
Sent: Wednesday, August 25, 2010 10:39 AM
To: Huang2, Wei; Przywara, Andre; Nitin Kamble
Cc: xen-devel
Subject: Re: [Xen-devel] Re: [PATCH] libxc: remove CPUID core information 
mangling

I meant it should remain the old way, since HVM virtual APIC IDs are
vcpu_id*2.

 -- Keir

On 25/08/2010 16:28, "Huang2, Wei" <Wei.Huang2@xxxxxxx> wrote:

> Hi Keir,
> 
> Do you mean that we should leave 80000008:ECX[15:12] as zero or in old way
> (i.e. (regs[2] & 0xf000u) + 1))? These bits can't be zero, unless we want to
> use legacy method in multi-core calculation.
> 
> -Wei
> 
> ========
> I think you shouldn't change handling of 80000008:ECX[15:12] since that does
> explicitly refer to APIC ID arrangement. The rest of your changes could be
> correct as far as I can tell from the reference manuals.
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
> 
> 





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