From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH] KVM: allow host header to be included even for !CONFIG_KVM Date: Fri, 17 May 2013 07:09:42 -0700 Message-ID: <871u95u28p.fsf@linaro.org> References: <20130321072955.GO3889@redhat.com> <87ppyshlq5.fsf@linaro.org> <1363891354.31522.17@snotra> <20130321191600.GG9382@redhat.com> <1363894393.31522.20@snotra> <20130321211736.GI9382@redhat.com> <20130324140114.GV3889@redhat.com> <87txnz9o7n.fsf@linaro.org> <20130515225201.GA2341@somewhere> <20130517010442.GB12928@somewhere> Mime-Version: 1.0 Content-Type: text/plain Cc: Gleb Natapov , Scott Wood , linaro-kernel@lists.linaro.org, Marcelo Tosatti , "open list\:KERNEL VIRTUAL MA..." , open list To: Frederic Weisbecker Return-path: In-Reply-To: <20130517010442.GB12928@somewhere> (Frederic Weisbecker's message of "Fri, 17 May 2013 03:04:43 +0200") Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Frederic Weisbecker writes: > On Thu, May 16, 2013 at 12:52:03AM +0200, Frederic Weisbecker wrote: >> On Mon, Mar 25, 2013 at 02:14:20PM -0700, Kevin Hilman wrote: >> > Gleb Natapov writes: >> > >> > > On Sun, Mar 24, 2013 at 02:44:26PM +0100, Frederic Weisbecker wrote: >> > >> 2013/3/21 Gleb Natapov : >> > >> > Isn't is simpler for kernel/context_tracking.c to define empty >> > >> > __guest_enter()/__guest_exit() if !CONFIG_KVM. >> > >> >> > >> That doesn't look right. Off-cases are usually handled from the >> > >> headers, right? So that we avoid iffdeffery ugliness in core code. >> > > Lets put it in linux/context_tracking.h header then. >> > >> > Here's a version to do that. >> > >> > Kevin >> > >> > From d9d909394479dd7ff90b7bddb95a564945406719 Mon Sep 17 00:00:00 2001 >> > From: Kevin Hilman >> > Date: Mon, 25 Mar 2013 14:12:41 -0700 >> > Subject: [PATCH v2] ontext_tracking: fix !CONFIG_KVM compile: add stub guest >> > enter/exit >> >> Sorry for my very delayed response... >> >> > >> > When KVM is not enabled, or not available on a platform, the KVM >> > headers should not be included. Instead, just define stub >> > __guest_[enter|exit] functions. >> >> May be it would be cleaner to move guest_enter/exit definitions altogether >> in linux/context_tracking.h >> >> After all that's where the implementation mostly belong to. >> >> Let me see if I can get that in shape. > > Does the following work for you? Nope. Since it still includs kvm_host.h on non-KVM builds, there is potential for problems. For example, on ARM (v3.10-rc1 + this patch) has this build error: CC kernel/context_tracking.o In file included from /work/kernel/linaro/nohz/arch/arm/include/asm/kvm_host.h:41:0, from /work/kernel/linaro/nohz/include/linux/kvm_host.h:34, from /work/kernel/linaro/nohz/kernel/context_tracking.c:18: /work/kernel/linaro/nohz/arch/arm/include/asm/kvm_vgic.h:38:6: warning: "CONFIG_KVM_ARM_MAX_VCPUS" is not defined [-Wundef] In file included from /work/kernel/linaro/nohz/arch/arm/include/asm/kvm_host.h:41:0, from /work/kernel/linaro/nohz/include/linux/kvm_host.h:34, from /work/kernel/linaro/nohz/kernel/context_tracking.c:18: /work/kernel/linaro/nohz/arch/arm/include/asm/kvm_vgic.h:59:11: error: 'CONFIG_KVM_ARM_MAX_VCPUS' undeclared here (not in a function) Kevin