Re: [Qemu-devel] [PATCH] Makefile: Move balloon.o, numa.o and bootdevice.o to common-obj-y

[Thomas Huth <thuth@redhat.com>]

On 14.06.2017 13:25, Paolo Bonzini wrote:
> 
> 
> On 14/06/2017 13:18, Thomas Huth wrote:
>> On 08.06.2017 16:18, Thomas Huth wrote:
>>> There does not seem to be any target specific code in these files, so
>>> we can put them into "common-obj" instead of "obj" to compile them only
>>> once for all targets.
>>
>> Self-NACK: balloon.c uses kvm_enabled() which in turn depends on
>> CONFIG_KVM ... and that flag is target-specific, so balloon.o can not be
>> moved to common-obj right now.
>>
>> We should poison CONFIG_KVM for common code ... I'll have a look into
>> that...
> 
> No, your patch is okay.
> 
> #if defined CONFIG_KVM || !defined NEED_CPU_H
> #define kvm_enabled()           (kvm_allowed)
> ...
> #else
> #define kvm_enabled()           (0)
> 
> In other words, kvm_enabled() forces itself to be 0 only in per-target
> files.  This is done mostly to limit the number of required stubs:
> target-independent APIs can be called from compile-once files and must
> be stubbed; target-specific APIs can only be called from per-target
> files, and their calls are culled by the compiler if !CONFIG_KVM.

OK, thanks for the explanation!
... but I now think my patch is still wrong, due to another reason:
numa.o indirectly uses ram_addr_t variables, and these are target
specific, as far as I can see. So at least that file should not be moved
to common-obj-y.

 Thomas