Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760718AbZCPORM (ORCPT ); Mon, 16 Mar 2009 10:17:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758726AbZCPOQz (ORCPT ); Mon, 16 Mar 2009 10:16:55 -0400 Received: from vpn.id2.novell.com ([195.33.99.129]:46724 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755725AbZCPOQy convert rfc822-to-8bit (ORCPT ); Mon, 16 Mar 2009 10:16:54 -0400 Message-Id: <49BE6D50.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.0 Date: Mon, 16 Mar 2009 14:16:32 +0000 From: "Jan Beulich" To: "Arjan van de Ven" 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 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> In-Reply-To: <20090315170945.08344b86@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 821 Lines: 18 >>> 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). New registers otoh are examples of where awareness is needed (SSE, AVX), as would be new privileged instructions. Jan -- 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/