[Xen-ia64-devel] privilege level of PV domain

To:	xen-ia64-devel <xen-ia64-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	[Xen-ia64-devel] privilege level of PV domain
From:	Jürgen Groß <juergen.gross@xxxxxxxxxxxxxxxxxxx>
Date:	Mon, 25 Jun 2007 08:34:02 +0200
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Hi,

I've got a question about the emulation of cpl=0 of a PV-domain.
Currently cpl=0 is emulated by using privilege level 2. Is there any special
reason not to use privilege level 1?

The reason for my question is the port of our mainframe operating system to
xen/ia64. We are using three different privilege levels today and it would
make the port much easier if we could keep this approach.
This is only possible, if cpl=0 of the domU is mapped to privilege level 1
by the hypervisor, of course.

If there is no architectural reason for using cpl=2 instead cpl=1, I would
prepare some patches...


Juergen

-- 
Juergen Gross                             Principal Developer
IP SW OS6                      Telephone: +49 (0) 89 636 47950
Fujitsu Siemens Computers         e-mail: juergen.gross@xxxxxxxxxxxxxxxxxxx
Otto-Hahn-Ring 6                Internet: www.fujitsu-siemens.com
D-81739 Muenchen         Company details: www.fujitsu-siemens.com/imprint.html

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