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From: "Benoît Canet" <benoit.canet@irqsave.net>
To: Gleb Natapov <gleb@redhat.com>
Cc: "Benoît Canet" <benoit.canet@irqsave.net>,
	pbonzini@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] KVM guest cpu L3 cache and cpufreq
Date: Mon, 26 Aug 2013 14:49:41 +0200	[thread overview]
Message-ID: <20130826124941.GA5418@irqsave.net> (raw)
In-Reply-To: <20130826124031.GB22977@redhat.com>


Hi,

Thanks for the answer.

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

Ok I'll try to do that.

> 
> > Similarly I noticed that the frequency in the guest was not reflecting the
> > frequency scaling of the host.
> > 
> 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

Benoît

> 
> > Could anything be done for this ? 
> > 
> > Best regards
> > 
> > Benoît
> 
> --
> 			Gleb.

  reply	other threads:[~2013-08-26 12:47 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-13 18:17 [Qemu-devel] KVM guest cpu L3 cache and cpufreq Benoît Canet
2013-08-26 12:40 ` Gleb Natapov
2013-08-26 12:49   ` Benoît Canet [this message]
2013-08-26 14:33     ` Gleb Natapov
2013-08-26 16:45       ` Benoît Canet
2013-08-26 20:47         ` Eduardo Habkost
2013-08-27 13:18           ` Benoît Canet
2013-08-27 13:17             ` Gleb Natapov
2013-08-27 13:20               ` Gleb Natapov
2013-08-27 13:35                 ` Benoît Canet
2013-08-27 13:39                   ` Gleb Natapov
2013-08-27 13:37             ` Eduardo Habkost

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