Message-ID: <49E4B8E9.7050703@zytor.com>
Date: Tue, 14 Apr 2009 09:25:13 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Avi Kivity <avi@redhat.com>
CC: Glauber Costa <glommer@redhat.com>, kvm@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] deal with interrupt shadow state for emulated instruction
References: <1239653210-10422-1-git-send-email-glommer@redhat.com> <49E45894.7090700@redhat.com> <49E4B4D4.1020903@zytor.com> <49E4B654.6060101@redhat.com>
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Avi Kivity wrote:
> 
> Why do we care?  The guest can only harm itself, and if it wants to
> disable interrupts, it would be a lot easier for it to run a plain 'cli'.
> 
> I guess it would be a problem if we emulated 'mov ss' for ordinary
> userspace or vm86 mode, but we don't.
> 

Well, the answer is that mov ss is an unprivileged instruction.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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