From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: [PATCH]Fix the bug of guest os
	installationfailure and win2k boot failure
Date: Tue, 18 Mar 2008 16:32:21 +0000
Message-ID: <C4059F15.1E0DF%keir.fraser@eu.citrix.com>
References: <C40543C0.1E069%keir.fraser@eu.citrix.com>
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On 18/3/08 10:02, "Keir Fraser" <keir.fraser@eu.citrix.com> wrote:

>> In your last sentence, do you mean that we still
>> need to do an entire I/O permission check (including CPL, IOPL, and TSS I/O
>> bitmap) in x86_emulate() for safety consideration? Thanks! :-)
> 
> Yes. Like I said: the CPL-IOPL check is very cheap, the TSS bitmap check is a
> little more expensive but probably relatively rare. And in any case the I/O
> port access latency is largely dominated by the VMEXIT/VMENTRY times. Also the
> devices we emulate are mostly managed by mmio.

I'll cook up a patch for this myself, by the way.

 -- Keir