Re: [PATCH] KVM: allow host header to be included even for !CONFIG_KVM

[Gleb Natapov <gleb@redhat.com>]

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@redhat.com> 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.

--
			Gleb.