Re: [Xen-devel] [PATCH 3/3 V3] XSA-60 security hole: cr0.cd handling

["Nakajima, Jun" <jun.nakajima@xxxxxxxxx>]

On Tue, Oct 22, 2013 at 7:55 AM, Jan Beulich <JBeulich@xxxxxxxx> wrote:

>>> On 21.10.13 at 17:55, "Liu, Jinsong" <jinsong.liu@xxxxxxxxx> wrote:
> From 4ff1e2955f67954e60562b29a00adea89e5b93ae Mon Sep 17 00:00:00 2001
> From: Liu Jinsong <jinsong.liu@xxxxxxxxx>
> Date: Thu, 17 Oct 2013 05:49:23 +0800
> Subject: [PATCH 3/3 V3] XSA-60 security hole: cr0.cd handling
>
> This patch solves XSA-60 security hole:
> 1. For guest w/o VT-d, and for guest with VT-d but snooped, Xen need
> do nothing, since hardware snoop mechanism has ensured cache coherency.
>
> 2. For guest with VT-d but non-snooped, cache coherency can not be
> guaranteed by h/w snoop, therefore it need emulate UC type to guest:
> 2.1). if it works w/ Intel EPT, set guest IA32_PAT fields as UC so that
> guest memory type are all UC.

Can you make sure that "setting guest IA32_PAT fields as UC" doesn't have a conflict with the existing (other) settings done by the guest?

 

--

Jun

Intel Open Source Technology Center

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