From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH] x86: Convert shadow-paging to Kconfig
Date: Tue, 19 Jan 2016 13:54:45 +0000
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To: Ian Campbell <ian.campbell@citrix.com>, Xen-devel <xen-devel@lists.xen.org>
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On 19/01/16 13:50, Ian Campbell wrote:
>
>>> What about nested virt?
>> Nested virt is completely broken with respect to migration.
> Sorry, I meant impact (generally) on nested, not WRT migration. AIUI shadow
> is required for either L1 or L2 (not sure which).

There is no requirement one way or another.  It function in any
combination you care to pick.

However, if you don't have HAP all the way down, Xen falls over very
quickly with spinlock contention if a guest actually starts doing some
real work.

~Andrew