From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0 of 3] create kvm_x86 Date: Sat, 01 Dec 2007 12:02:00 +0200 Message-ID: <47513118.7050104@qumranet.com> References: <4743F5AE.8090707@de.ibm.com> <4743F7DF.4000107@qumranet.com> <1196284556.9247.22.camel@basalt> <474FBB17.6080800@qumranet.com> <42DFA526FC41B1429CE7279EF83C6BDCA397C1@pdsmsx415.ccr.corp.intel.com> <474FD234.5060203@qumranet.com> <1196448210.7103.47.camel@basalt> <4750732B.7070502@qumranet.com> <1196456956.7103.60.camel@basalt> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: carsteno-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org, kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, kvm-ppc-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, "Zhang, Xiantao" To: Hollis Blanchard Return-path: In-Reply-To: <1196456956.7103.60.camel@basalt> 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 Hollis Blanchard wrote: >> >> These cannot use the same method, since we need to support both vmx and >> svm in the same binary. The arch specific members aren't the same size, >> nor do the symbols they use have the same visibility. >> > > I have never understood this. Why on earth do you need to support VMX > and SVM in the same binary? For example, when would you overwrite > kvm_x86_ops after initialization? If you wouldn't, then why are you > using function pointers instead of the linker? > Consider a non-modular build; common code needs to call either svm_vcpu_load() or vmx_vcpu_load() depending on the current hardware. I imagine it could be done using linker tricks (duplicating the common code to be linked twice, once per subarch, and leaving a stub to detect which duplicate needs to be used), but I never found either the time or necessity to do them. > PowerPC will also need to support multiple processor types, and so I > expect to have one kvm_arch structure for each. That also means struct > kvm_arch must be the *last* member in struct kvm, which is not how it is > shown above. > Do you plan to support multiple processor types in a single binary as well? Or require modules and compile them multiple times? (that was how AMD support was initially added; it was changed before merging). -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- 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