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Date: Mon, 26 Aug 2013 14:49:41 +0200
From: =?iso-8859-1?Q?Beno=EEt?= Canet <benoit.canet@irqsave.net>
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Subject: Re: [Qemu-devel] KVM guest cpu L3 cache and cpufreq
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To: Gleb Natapov <gleb@redhat.com>
Cc: =?iso-8859-1?Q?Beno=EEt?= Canet <benoit.canet@irqsave.net>, pbonzini@redhat.com, qemu-devel@nongnu.org


Hi,

Thanks for the answer.

> On Tue, Aug 13, 2013 at 08:17:13PM +0200, Beno=EEt Canet wrote:
> >=20
> > Hi,
> >=20
> > I noticed that the l3 cache size of a guest /proc/cpuinfo is not the =
same as
> > the l3 cache size of the host.
> >=20
> > I did not found any references to this in the qemu and KVM code.
> >=20
> > Is the size of the guest L3 cache fixed in hardware ?
> >=20
> No, it is hardcoded somewhere in qemu cpuid code.
>=20
> > Can a patch be written to set it ?
> >=20
> Yes.

Ok I'll try to do that.

>=20
> > Similarly I noticed that the frequency in the guest was not reflectin=
g the
> > frequency scaling of the host.
> >=20
> Not sure what you mean here. Frequency as seen where?

The frequency seen in the host /proc/cpuinfo and the guest /proc/cpuinfo =
differs
when a governor kick the cpu frequency scaling: the guest still show the =
maximum
frequency of the cpu.

Could this value be reflected dynamically ?

Best regards

Beno=EEt

>=20
> > Could anything be done for this ?=20
> >=20
> > Best regards
> >=20
> > Beno=EEt
>=20
> --
> 			Gleb.