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Date: Tue, 27 Aug 2013 16:39:54 +0300
From: Gleb Natapov <gleb@redhat.com>
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Subject: Re: [Qemu-devel] KVM guest cpu L3 cache and cpufreq
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To: =?utf-8?Q?Beno=C3=AEt?= Canet <benoit.canet@irqsave.net>
Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, Eduardo Habkost <ehabkost@redhat.com>, Andreas =?utf-8?Q?F=C3=A4rber?= <afaerber@suse.de>, Igor Mammedov <imammedo@redhat.com>

On Tue, Aug 27, 2013 at 03:35:33PM +0200, Beno=C3=AEt Canet wrote:
> > > > If I understand correctly changing the CPUID L3 cache infos in QEMU=
 will change
> > > > the value displayed in the guest /proc/cpuinfo but will not change =
the size of
> > > > the l3 cache used by the hardware. So I am chasing a cosmetic bug.
> > > > If it right ?
> > > >=20
> > > Right.
> > >=20
> > Well, actually not entirely. An application can query cache sizes and
> > adjust its algorithms accordingly in which case performance can be
> > suboptimal if information in a guest is not accurate.
>=20
> So maybe what is missing is a CPUID passthrough mode triggered when -cpu =
host
> is used ?
>=20
That is missing too, but it should not be default with other CPU models.

--
			Gleb.