Gleb Natapov <gleb@xxxxxxxxxx> 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 <gleb@xxxxxxxxxx> 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
>> >> ><asm/kvm*.h> 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 <asm/kvm*.h> 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 <khilman@xxxxxxxxxx>
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 <fweisbec@xxxxxxxxx>
Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxx>
---
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 <linux/context_tracking.h>
-#include <linux/kvm_host.h>
#include <linux/rcupdate.h>
#include <linux/sched.h>
#include <linux/hardirq.h>
#include <linux/export.h>
+#if IS_ENABLED(CONFIG_KVM)
+#include <linux/kvm_host.h>
+#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
--
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