From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerone Young Subject: Re: [Disscussion] Moving x86 code out of kvm.h Date: Thu, 15 Nov 2007 10:44:13 -0600 Message-ID: <1195145053.5696.5.camel@thinkpad> References: <1195115055.21627.17.camel@thinkpad> <473C0494.2080404@qumranet.com> Reply-To: jyoung5-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , kvm-ppc-devel To: Avi Kivity Return-path: In-Reply-To: <473C0494.2080404-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Thu, 2007-11-15 at 10:34 +0200, Avi Kivity wrote: > Jerone Young wrote: > > This is a continuation of a conversation I have been having with Izik > > Eidus on IRC today. > > > > I plan on moving x86 code out of kvm.h and into kvm-x86.h. kvm-x86.h > > would then include kvm.h and would be included by files like svm.c > > instead of kvm.h. > > > > > > Which kvm.h are we talking about? include/linux/kvm.h or drivers/kvm/kvm.h? Whoops should have been more clear about this. It was late for me :-) But I was first referring to inclue/linux/kvm.h. I believe I actually started looking at drivers/kvm/kvm.h at the same time (which is why my email is so screwed, but this is not as big of a deal for now). Never the less it looks like the discussion has taken off. I'll just join in that. > > > Izik pointed out a big issue with this approach and that is it breaks > > compatibility with older userspace. We believe that everyone still cares > > that older userspace should be able to compile against a newer kvm > > kernels. Is this true or should we just dump it? > > > > Of course we can't break compatibility without an excellent reason. > > > Assuming this is true, we have come up with an interesting solution to > > the problem. > > > > - creation of new header name "portablekvm.h" (please give a better name > > if you know one). This would be the new place for common code that would > > normally be kvm.h. > > > > - still create header "kvm-x86.h" for x86 code and would include this > > new "portablekvm.h" header. > > > > - keep compatibility with older userspace by taking header "kvm.h" and > > jsut have it include kvm-x86.h & portablekvm.h and have no other code > > (unless it's for compatibility). > > > > What does everyone thing about this ? > > > > > > Have kvm.h include > > > Also a side discussion is should we really start thinking about having a > > userspace header and stop userspace apps from including kernel headers. > > This does lead to a problem where if the kernel header is updated the > > userspace header must also be updated (but maybe it's time to bite the > > bullet)? > > > > > > The userspace header is include/linux/kvm.h. No need to be cruel to > innocent bullets. > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/