From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [PATCH 4/9] KVM: VMX: Cache cpl
Date: Tue, 8 Mar 2011 16:38:28 +0200
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Cc: Marcelo Tosatti <mtosatti@redhat.com>, kvm@vger.kernel.org,
	Jan Kiszka <jan.kiszka@siemens.com>
To: Avi Kivity <avi@redhat.com>
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On Tue, Mar 08, 2011 at 04:29:10PM +0200, Avi Kivity wrote:
> On 03/08/2011 04:20 PM, Gleb Natapov wrote:
> >On Tue, Mar 08, 2011 at 03:57:40PM +0200, Avi Kivity wrote:
> >>  We may read the cpl quite often in the same vmexit (instruction privilege
> >>  check, memory access checks for instruction and operands), so we gain
> >>  a bit if we cache the value.
> >>
> >Shouldn't VCPU_EXREG_CPL be cleared in vmx_set_efer too?
> 
> I anticipated that question (which really means that a comment is
> needed).  Flipping EFER.LMA is done by flipping CR0.PG (and doesn't
> affect cpl. in any case).
> 
Ah, so you can't clear LMA by writing to EFER.

--
			Gleb.