From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@qumranet.com>
Subject: Re: [PATCH 3/3] KVM: SVM: enable LBRV virtualization
Date: Wed, 13 Feb 2008 12:20:07 +0200
Message-ID: <47B2C457.5040908@qumranet.com>
References: <1202830030-16023-1-git-send-email-joerg.roedel@amd.com>
	<1202830030-16023-4-git-send-email-joerg.roedel@amd.com>
	<47B2BD82.1050800@qumranet.com> <20080213100354.GA22943@amd.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Cc: kvm-devel@lists.sourceforge.net,
	Markus Rechberger <markus.rechberger@amd.com>
To: Joerg Roedel <joerg.roedel@amd.com>
Return-path: <kvm-devel-bounces@lists.sourceforge.net>
In-Reply-To: <20080213100354.GA22943@amd.com>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/kvm-devel>,
	<mailto:kvm-devel-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=kvm-devel>
List-Post: <mailto:kvm-devel@lists.sourceforge.net>
List-Help: <mailto:kvm-devel-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/kvm-devel>,
	<mailto:kvm-devel-request@lists.sourceforge.net?subject=subscribe>
Sender: kvm-devel-bounces@lists.sourceforge.net
Errors-To: kvm-devel-bounces@lists.sourceforge.net
List-Id: kvm.vger.kernel.org

Joerg Roedel wrote:
>>>  
>>>       
>> This still has the same issue as the previous patchset:  if the guest enables some other bit 
>> in MSR_IA32_DEBUCTLMSR, we silently ignore it.  We should either pr_unimpl() on such bits or 
>> not handle them (ultimately injecting a #GP).
>>     
>
> Thats not true. The patch saves the MSR value in vmcb->save.dbgctl. This
> value is returned on reads of that MSR. So no bit is ignored. This value
> in the VMCB is also used as the guests copy of that MSR if LBR
> virtualization is enabled. 

Right, my mistake.

-- 
Any sufficiently difficult bug is indistinguishable from a feature.


-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/