Re: [Xen-devel] Re: [GIT PULL] xen /proc/mtrr implementation

[Gerd Hoffmann]

> > > > No, the linux kernel probably should do the wrmsr on one cpu only then.
> > > Why?

> | The change of MTRR's on _any_ of the guest CPUs in a dom0 context
> | should immediately be refected on all CPUs. Assymetric MTRR
> | settings are madness.

Exactly.  And thats why it is pointless to let the dom0 kernel write the 
mtrr msrs on more than one cpu.

> > > > Oops, the third "proper technical solutions" is missing.
> > > Yeah, the third one is to not touch MTRRs after bootup and use PAT.
> > Works only in case the CPU has PAT support.
>
> Which specific CPU without PAT support do you worry about?

For example:  I have a Notebook here, with MTRR and without PAT 
according to the boot log.  "Pentium III (Coppermine)" says /proc/cpuinfo.

cheers,
  Gerd
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