Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756238Ab3EQOfV (ORCPT ); Fri, 17 May 2013 10:35:21 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:53257 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755317Ab3EQOfT (ORCPT ); Fri, 17 May 2013 10:35:19 -0400 Date: Fri, 17 May 2013 16:34:54 +0200 From: Frederic Weisbecker To: Kevin Hilman Cc: Gleb Natapov , Scott Wood , linaro-kernel@lists.linaro.org, Marcelo Tosatti , "open list:KERNEL VIRTUAL MA..." , open list Subject: Re: [PATCH] KVM: allow host header to be included even for !CONFIG_KVM Message-ID: <20130517143445.GA23086@somewhere> References: <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> <871u95u28p.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871u95u28p.fsf@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6428 Lines: 201 On Fri, May 17, 2013 at 07:09:42AM -0700, Kevin Hilman wrote: > 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) Sorry I forgot to remove the include to kvm_host.h in context_tracking.c, here's the fixed patch: diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index 365f4a6..fc09d7b 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -3,6 +3,7 @@ #include #include +#include #include struct context_tracking { @@ -19,6 +20,26 @@ struct context_tracking { } state; }; +static inline void __guest_enter(void) +{ + /* + * This is running in ioctl context so we can avoid + * the call to vtime_account() with its unnecessary idle check. + */ + vtime_account_system(current); + current->flags |= PF_VCPU; +} + +static inline void __guest_exit(void) +{ + /* + * This is running in ioctl context so we can avoid + * the call to vtime_account() with its unnecessary idle check. + */ + vtime_account_system(current); + current->flags &= ~PF_VCPU; +} + #ifdef CONFIG_CONTEXT_TRACKING DECLARE_PER_CPU(struct context_tracking, context_tracking); @@ -35,6 +56,9 @@ static inline bool context_tracking_active(void) extern void user_enter(void); extern void user_exit(void); +extern void guest_enter(void); +extern void guest_exit(void); + static inline enum ctx_state exception_enter(void) { enum ctx_state prev_ctx; @@ -57,6 +81,17 @@ extern void context_tracking_task_switch(struct task_struct *prev, static inline bool context_tracking_in_user(void) { return false; } static inline void user_enter(void) { } static inline void user_exit(void) { } + +static inline void guest_enter(void) +{ + __guest_enter(); +} + +static inline void guest_exit(void) +{ + __guest_exit(); +} + static inline enum ctx_state exception_enter(void) { return 0; } static inline void exception_exit(enum ctx_state prev_ctx) { } static inline void context_tracking_task_switch(struct task_struct *prev, diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f0eea07..8db53cf 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -760,42 +761,6 @@ static inline int kvm_iommu_unmap_guest(struct kvm *kvm) } #endif -static inline void __guest_enter(void) -{ - /* - * This is running in ioctl context so we can avoid - * the call to vtime_account() with its unnecessary idle check. - */ - vtime_account_system(current); - current->flags |= PF_VCPU; -} - -static inline void __guest_exit(void) -{ - /* - * This is running in ioctl context so we can avoid - * the call to vtime_account() with its unnecessary idle check. - */ - vtime_account_system(current); - current->flags &= ~PF_VCPU; -} - -#ifdef CONFIG_CONTEXT_TRACKING -extern void guest_enter(void); -extern void guest_exit(void); - -#else /* !CONFIG_CONTEXT_TRACKING */ -static inline void guest_enter(void) -{ - __guest_enter(); -} - -static inline void guest_exit(void) -{ - __guest_exit(); -} -#endif /* !CONFIG_CONTEXT_TRACKING */ - static inline void kvm_guest_enter(void) { unsigned long flags; diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 65349f0..85bdde1 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -15,7 +15,6 @@ */ #include -#include #include #include #include -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/