From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Ehrhardt Subject: Re: [PATCH]0/2 Patches to furthure split kvm_init Date: Fri, 30 Nov 2007 10:52:37 +0100 Message-ID: <474FDD65.5070208@linux.vnet.ibm.com> References: <42DFA526FC41B1429CE7279EF83C6BDCA394B2@pdsmsx415.ccr.corp.intel.com> <474E8D88.4090508@linux.vnet.ibm.com> <474FBF0D.7020601@qumranet.com> <42DFA526FC41B1429CE7279EF83C6BDCA397B9@pdsmsx415.ccr.corp.intel.com> <474FCB79.2010008@qumranet.com> <42DFA526FC41B1429CE7279EF83C6BDCA397CF@pdsmsx415.ccr.corp.intel.com> <474FD21E.8030900@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, carsteno-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org, Hollis Blanchard , "Zhang, Xiantao" To: Avi Kivity Return-path: In-Reply-To: <474FD21E.8030900-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 Avi Kivity wrote: > Zhang, Xiantao wrote: >> Avi Kivity wrote: >> = >>> Zhang, Xiantao wrote: >>> = >>>> Avi Kivity wrote: >>>> >>>> = >>>>> Christian Ehrhardt wrote: >>>>> >>>>> = >>>>>> Hi Xiantao, >>>>>> it looks good to me to move kvm_vcpu_cache out to the x86 specific >>>>>> code = >>>>>> >>>>>> = >>>>> Why is that? Do other archs not want kvm_vcpu_cache, or is it just >>>>> the alignment? = >>>>> >>>>> = >>>> At lease we didn't fall across the similar requirements about such >>>> alignment issues in IA64. = >>>> >>>> = >>> What I mean is, other archs do require kvm_vcpu_cache (without the >>> alignment), so why move the code? Just make the alignment arch >>> dependent with a #define. >>> = >> I think IA64 TOTALLY doen't need this logic, so do the move:) >> >> = > = > Ah, I see. It isn't just the alignment. How do you allocate kvm_vcpu, th= en? > = > = > What about s390 and powerpc? I imagine they don't have an alignment > issue, but do they have a totally unique way of allocating vcpus as well? On one hand we don't have "these" alignment issues, but on the other hand w= e have some complex offset logic to integrate structures and handler vector= s&code (which need special alignment). The major problem is that the our prototype currently only supports one vcp= u per guest and therefore we didn't think a lot about e.g. kmem_cache for v= cpu structures. >>From my current point of view we may be able to use a kmem_cache and be abl= e to do all sophisticated ppc stuff in an arch function filling the arch pa= rt of vcpu, but that opinion may change when we look further into it while = implementing muli-vcpu support per guest. Because of that I think atm your CONFIG_HAVE_SPECIAL_VCPU_ALLOC suggestion = would be nice, with that we could do either way later without restructuring= the generic code too much. I added Hollis to the direct CC List, because this ppc code is his creation= he might be able to give us a much clearer insight how ppc vcpu allocation= in future might look like. > Maybe we should just #ifndef CONFIG_IA64 (or #ifdef > CONFIG_HAVE_SPECIAL_VCPU_ALLOC) this bit instead of duplicating it for > s390 and ppc. > = -- = Gr=FCsse / regards, = Christian Ehrhardt IBM Linux Technology Center, Open Virtualization +49 7031/16-3385 Ehrhardt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org Ehrhardt-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org IBM Deutschland Entwicklung GmbH Vorsitzender des Aufsichtsrats: Johann Weihen = Gesch=E4ftsf=FChrung: Herbert Kircher = Sitz der Gesellschaft: B=F6blingen Registergericht: Amtsgericht Stuttgart, HRB 243294 ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4