From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir@xensource.com>
Subject: Re: VMX: emulated guest use SYSENTER MSRs
Date: Fri, 06 Jul 2007 13:52:37 +0100
Message-ID: <C2B3F9A5.11FDC%keir@xensource.com>
References: <468E548C.76E4.0078.0@novell.com>
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To: Jan Beulich <jbeulich@novell.com>, xen-devel@lists.xensource.com
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Probably because the existing code must remain anyway (since not all VMX
CPUs support the MSR bitmap), and the benefit of avoiding the intercepts on
CPUs that do support it would have entirely negligible performance benefit,
since the MSRs are written only at start of day. We could add calls to avoid
the intercepts anyway though, if you want to provide a patch.

 -- Keir

On 6/7/07 13:41, "Jan Beulich" <jbeulich@novell.com> wrote:

> What is the reason for not simply clearing the MSR bitmap bits for these three
> MSRs, and rather handling the reads/writes in software?
> 
> Jan
> 
> 
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