Re: [XEN PATCH v3] arm/mem_access: add conditional build of mem_access.c

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 14/05/2024 09:10, Jan Beulich wrote:
> On 10.05.2024 14:32, Alessandro Zucchelli wrote:
> > --- a/xen/arch/arm/include/asm/mem_access.h
> > +++ b/xen/arch/arm/include/asm/mem_access.h
> > @@ -17,6 +17,8 @@
> >   #ifndef _ASM_ARM_MEM_ACCESS_H
> >   #define _ASM_ARM_MEM_ACCESS_H
> >   
> > +#include <xen/types.h>
> > +
> >   static inline
> >   bool p2m_mem_access_emulate_check(struct vcpu *v,
> >                                     const struct vm_event_st *rsp)
> > @@ -35,12 +37,28 @@ static inline bool p2m_mem_access_sanity_check(struct 
> > domain *d)
> >    * Send mem event based on the access. Boolean return value indicates if trap
> >    * needs to be injected into guest.
> >    */
> > +#ifdef CONFIG_MEM_ACCESS
> >   bool p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec);
> >   
> >   struct page_info*
> >   p2m_mem_access_check_and_get_page(vaddr_t gva, unsigned long flag,
> >                                     const struct vcpu *v);
> > +#else
> > +
> > +static inline bool
> > +p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec)
> > +{
> > +    return false;
> > +}
> > +
> > +static inline struct page_info*
> > +p2m_mem_access_check_and_get_page(vaddr_t gva, unsigned long flag,
> > +                                  const struct vcpu *v)
> > +{
> > +    return NULL;
> > +}
> >   
> > +#endif /*CONFIG_MEM_ACCESS*/
> Why would each arch need to repeat these stubs? IOW why would they not
> live in xen/mem_access.h?
Because they are not used by nor defined in common code. It is pure 
coincidence they are named the same. If at some point, some code can be 
shared, then yes I would agree it could be common.
Cheers,

--
Julien Grall