Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758030AbZCPO30 (ORCPT ); Mon, 16 Mar 2009 10:29:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755395AbZCPO3Q (ORCPT ); Mon, 16 Mar 2009 10:29:16 -0400 Received: from casper.infradead.org ([85.118.1.10]:43447 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754816AbZCPO3Q (ORCPT ); Mon, 16 Mar 2009 10:29:16 -0400 Date: Mon, 16 Mar 2009 07:29:04 -0700 From: Arjan van de Ven To: "Jan Beulich" Cc: "Jeremy Fitzhardinge" , "Jeremy Fitzhardinge" , "the arch/x86 maintainers" , "Xen-devel" , "Linux Kernel Mailing List" , "H. Peter Anvin" Subject: Re: [Xen-devel] [PATCH 10/24] xen: mask XSAVE from cpuid Message-ID: <20090316072904.733e7e43@infradead.org> In-Reply-To: <49BE6D50.76E4.0078.0@novell.com> References: <1236931920-6861-1-git-send-email-jeremy@goop.org> <1236931920-6861-11-git-send-email-jeremy@goop.org> <49BA3A84.76E4.0078.0@novell.com> <49BA7810.6090807@goop.org> <49BD4CE1.6040100@zytor.com> <49BD6D0E.1010107@goop.org> <20090315154718.00353625@infradead.org> <49BD97C6.2070401@goop.org> <20090315170945.08344b86@infradead.org> <49BE6D50.76E4.0078.0@novell.com> Organization: Intel X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1035 Lines: 26 On Mon, 16 Mar 2009 14:16:32 +0000 "Jan Beulich" wrote: > >>> Arjan van de Ven 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 ? -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/