Re: [Xen-devel] [PATCH 10/24] xen: mask XSAVE from cpuid

Arjan van de Ven
2009-03-16T14:29:26Z

On Mon, 16 Mar 2009 14:16:32 +0000
"Jan Beulich" <jbeulich@novell.com> wrote:

> >>> Arjan van de Ven <arjan@infradead.org> 16.03.09 01:09 >>>
> >Well.. pretty much all new instructions need Xen modifications due to
> >the need to be emulate to deal with traps/vmexits/etc right?
> >So I don't quite see many cpuid bits that would NOT involve some Xen
> >modification or another ;)
>
> No, new (user-mode accessible) instructions represent precisely the
> kind of extension that do not require hypervisor (or OS) awareness
> (see SSE2 etc, AES, FMA).

so Xen doesn't need to handle a case where the kernel does AES on
uncached IO memory ?

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