Re: [Qemu-devel] [PATCH v1 for-2.11 09/10] s390x/kvm: move KVM declarations and stubs to separate files

[Philippe Mathieu-Daudé]

On 08/17/2017 09:35 AM, Thomas Huth wrote:
> On 17.08.2017 13:40, Philippe Mathieu-Daudé wrote:
> > Hi David,
> >
> > On 08/17/2017 06:22 AM, David Hildenbrand wrote:
> > > Let's do it just like the other architectures. Introduce kvm-stub.c
> > > for stubs and kvm_s390x.h for the declarations.
> > >
> > > Add a fake declaration of struct kvm_s390_irq so we don't need other
> > > ugly CONFIG_KVM checks.
> >
> > You can use an opaque pointer to avoid that ("bridge" design pattern).
> >
> > It involves few more changes but looks safer.
>
> There is maybe even a simpler solution than that, see below ...
>
> [...]
> > >    feat-src = $(SRC_PATH)/target/$(TARGET_BASE_ARCH)/
> > > diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> > > index 74d5b35..aeb730c 100644
> > > --- a/target/s390x/cpu.h
> > > +++ b/target/s390x/cpu.h
> > > @@ -41,6 +41,7 @@
> > >    #include "exec/cpu-all.h"
> > >      #include "fpu/softfloat.h"
> > > +#include "kvm_s390x.h"
>
> Do we still need that? cpu.h should theoretically be independent from
> kvm now, shouldn't it? And for the .c files, it's likely better to
> include kvm_s390x.h directly there if they require it.

Oh you totally right, I missed this include.

[...]
> > > +#ifndef KVM_S390X_H
> > > +#define KVM_S390X_H
> > > +
> > > +#include "sysemu/kvm.h"
> > > +
> > > +#ifndef CONFIG_KVM
> > > +struct kvm_s390_irq {};
> > > +#endif /* CONFIG_KVM */
> >
> > change by
> >
> > typedef struct kvm_s390_irq kvm_s390_irq_t;
>
> May I suggest to simply use this instead:
>
> struct kvm_s390_irq;
>
> No need to switch for a typedef here, you can simply use this anonymous
> struct declaration, I think.