Re: [RFC/PATCH 1/5] context tracking: conditionalize guest support based on CONFIG_KVM

[Kevin Hilman]

Frederic Weisbecker <fweisbec@xxxxxxxxx> writes:

> On Wed, Feb 20, 2013 at 11:41:38AM -0800, Kevin Hilman wrote:
>> So that it can build on !KVM systems too.
>> 
>> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxx>
>> ---
>>  kernel/context_tracking.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>> 
>> diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
>> index 74f68f4..6fe96b1 100644
>> --- a/kernel/context_tracking.c
>> +++ b/kernel/context_tracking.c
>> @@ -1,5 +1,7 @@
>>  #include <linux/context_tracking.h>
>> +#ifdef CONFIG_KVM
>>  #include <linux/kvm_host.h>
>> +#endif
>
> The header should take care of the off-case, no need to ifdef its inclusion.

In their current form, the headers will not build on platforms without
KVM support.  For example, these platforms (like ARM) don't even have
<asm/kvm.h> or <asm/kvm_host.h>.

>>  #include <linux/rcupdate.h>
>>  #include <linux/sched.h>
>>  #include <linux/hardirq.h>
>> @@ -62,6 +64,7 @@ void user_exit(void)
>>  	local_irq_restore(flags);
>>  }
>>  
>> +#ifdef CONFIG_KVM
>>  void guest_enter(void)
>>  {
>>  	if (vtime_accounting_enabled())
>> @@ -79,6 +82,7 @@ void guest_exit(void)
>>  		__guest_exit();
>>  }
>>  EXPORT_SYMBOL_GPL(guest_exit);
>> +#endif
>
> Kvm might be built as a module so we can't actually do this unfortunately.

Ah, right.  How bout using 

#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)

for both conditionals above?  Updated patch below.

Kevin