From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] CPUID level 0x00000007:0 (ebx) is word 9, instead of word 7 Date: Wed, 01 Jun 2011 07:47:24 +0100 Message-ID: References: <4DE5F9ED0200007800044BCD@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4DE5F9ED0200007800044BCD@vpn.id2.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich , Xin Li Cc: xen-devel List-Id: xen-devel@lists.xenproject.org On 01/06/2011 07:35, "Jan Beulich" wrote: >>>> On 31.05.11 at 16:59, "Li, Xin" wrote: >>> can't see why we would need to stay in sync with Linux's capability >>> array indices. >> >> why? Typically we reuse Linux code unless Xen has its special logic. > > So you would suggest leaving indices 7 and 8 unused instead? > Looking at current Linux, we certainly could convert Xen to use > index 8 for virtualization features, but since these are being > tracked differently already anyway I don't see a value in this. > > As to index 7, just look at ARAT - we're already diverging from > Linux here (having it allocated in index 3). > > Bottom line is that I think keeping the names (and in various cases > the grouping together, namely when the bits are grouped together > in some CPUID leaf's output) in sync is desirable, but following > Linux to the bit doesn't always make sense. After all, some thinking > will always be necessary when porting over patches. Agreed. -- Keir > Jan >