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: Thu, 21 Mar 2013 17:02:15 -0700 Message-ID: <878v5ggv3s.fsf@linaro.org> References: <1363306426-27209-1-git-send-email-khilman@linaro.org> <1363823921.25034.35@snotra> <20130321072955.GO3889@redhat.com> <87ppyshlq5.fsf@linaro.org> <1363891354.31522.17@snotra> <20130321191600.GG9382@redhat.com> <1363894393.31522.20@snotra> <20130321211736.GI9382@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Scott Wood , Frederic Weisbecker , linaro-kernel@lists.linaro.org, Marcelo Tosatti , "open list\:KERNEL VIRTUAL MA..." , open list To: Gleb Natapov Return-path: In-Reply-To: <20130321211736.GI9382@redhat.com> (Gleb Natapov's message of "Thu, 21 Mar 2013 23:17:36 +0200") Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Gleb Natapov writes: > On Thu, Mar 21, 2013 at 02:33:13PM -0500, Scott Wood wrote: >> On 03/21/2013 02:16:00 PM, Gleb Natapov wrote: >> >On Thu, Mar 21, 2013 at 01:42:34PM -0500, Scott Wood wrote: >> >> On 03/21/2013 09:27:14 AM, Kevin Hilman wrote: >> >> >Gleb Natapov writes: >> >> > >> >> >> On Wed, Mar 20, 2013 at 06:58:41PM -0500, Scott Wood wrote: >> >> >>> Why can't the entirety kvm_host.h be included regardless of >> >> >>> CONFIG_KVM, just like most other feature-specific headers? Why >> >> >>> can't the if/else just go around the functions that you want to >> >> >stub >> >> >>> out for non-KVM builds? >> >> >>> >> >> >> Kevin, >> >> >> >> >> >> What compilation failure this patch fixes? I presume >> >something ARM >> >> >> related. >> >> > >> >> >Not specficially ARM related, but more context tracking related >> >since >> >> >kernel/context_tracking.c pulls in kvm_host.h, which attempts to >> >> >pull in >> >> > which may not exist on some platforms. >> >> > >> >> >At least for ARM, KVM support was added in v3.9 so this patch can >> >> >probably be dropped since the non-KVM builds on ARM now work. >> >But any >> >> >platform without the will still be broken when >> >trying to >> >> >build the context tracker. >> >> >> >> Maybe other platforms should get empty asm/kvm*.h files. Is there >> >> anything from those files that the linux/kvm*.h headers need to >> >> build? >> >> >> >arch things. kvm_vcpu_arch, kvm_arch_memory_slot, kvm_arch etc. >> >> Could define them as empty structs. >> > Isn't is simpler for kernel/context_tracking.c to define empty > __guest_enter()/__guest_exit() if !CONFIG_KVM. I proposed something like that in an earlier version but Frederic asked me to propose a fix to the KVM headers instead. Just in case fixing the context tracking subsystem is preferred, the patch below fixes the problem also. Kevin >>From f22995a262144d0d61705fa72134694d911283eb Mon Sep 17 00:00:00 2001 From: Kevin Hilman Date: Thu, 21 Mar 2013 16:57:14 -0700 Subject: [PATCH] context_tracking: fix !CONFIG_KVM compile: add stub guest enter/exit 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. Cc: Frederic Weisbecker Signed-off-by: Kevin Hilman --- kernel/context_tracking.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 65349f0..64b0f80 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -15,12 +15,18 @@ */ #include -#include #include #include #include #include +#if IS_ENABLED(CONFIG_KVM) +#include +#else +#define __guest_enter() +#define __guest_exit() +#endif + DEFINE_PER_CPU(struct context_tracking, context_tracking) = { #ifdef CONFIG_CONTEXT_TRACKING_FORCE .active = true, -- 1.8.2