From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Vrabel <david.vrabel@citrix.com>
Subject: Re: Xen PV PTE ABI (or lack thereof)
Date: Thu, 21 Jan 2016 14:29:22 +0000
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To: Andrew Cooper <andrew.cooper3@citrix.com>, Jan Beulich <JBeulich@suse.com>
Cc: George Dunlap <george.dunlap@eu.citrix.com>, Huaitong Han <huaitong.han@intel.com>, Tim Deegan <tim@xen.org>, Xen-devel List <xen-devel@lists.xen.org>
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On 21/01/16 13:17, Andrew Cooper wrote:
> 
> As we see with the Protection Key feature, newer hardware feature start
> using bits which were previously software available, and we absolutely
> don't want to be in a position where our ABI prevents us from ever
> supporting a new feature.

I don't see a problem in not supporting new features in /PV/ guests.

I think we should document the PV ABI as-is. i.e., that these two PTE
bits are not available for PV guest use.

David